An overview of California’s ongoing and extraordinary drought: a tale of exceptional dryness and record warmth

Filed in Uncategorized by on July 20, 2014 658 Comments

Event narrative

Droughts historically have a way of sneaking up on California, and the extraordinary 2012-2014 drought has been no exception.

California precipitation during 2013 was by far the lowest on record. (NOAA/NCDC)

Year-to-year and even season-to-season rainfall variability is quite high in this part of the world, which means that it’s nearly impossible to know whether a single dry year (or season) portends the beginning of a much more prolonged or intense dry period. Indeed–the 2012-2013 rainy season had an extremely wet start–so wet, in fact, that an additional large storm during December 2012 would likely have led to serious and widespread flooding throughout Northern California. But no additional significant storms did occur during December 2012–nor during January 2013…nor February, March, April, or May. In fact, January-June 2013 was the driest start to the calendar year  on record for the state of California in at least 118 years of record keeping. Some parts of the state saw virtually no precipitation at all during this period, which made for an especially stark contrast with the extremely wet conditions experienced just a few months earlier.

 

The role of the Ridiculously Resilient Ridge

How did this drastic change occur so quickly? The second half of the 2012-2013 Water Year saw the development of the now infamous Ridiculously Resilient Ridge (or RRR)–an extraordinarily persistent region of high pressure over the northeastern Pacific Ocean in the middle atmosphere that forced the mid-latitude storm track well to the north of its typical position and prevented winter storms from reaching California.

The Ridiculously Resilient Ridge in 2013. (NCEP/ESRL)

The Ridiculously Resilient Ridge in 2013. (NCEP/ESRL)

While the RRR did become less prominent during the summer months of 2013, it returned with even greater intensity  by the fall. In fact, by November 2013, the RRR resulted in such an anomalous high-amplitude flow pattern that much of Alaska–even regions north of the Arctic Circle–experienced record warmth and precipitation, which led to several high impact weather events (including ice storms and enormous avalanches). In California, meanwhile, the precipitation spigot remained tightly closed as Pacific storms rode thousands of miles to the north of where they typically would have been. Most of these winter storms missed even Oregon and Washington, triggering a drought that is now being experienced rather acutely in these regions in the form of massive, nearly uncontrollable wildfires this summer. In California, conditions during January were so warm and dry that wildfires broke out in the far north in the dead of winter–an essentially unprecedented event in this region.

 

Temporary mid-winter relief

By the beginning of February, the RRR began to lose some of its intensity (and, more importantly, much of its seemingly indomitable persistence). A major pattern change did finally allow a series of significant storm systems to affect much of California, including a fairly impressive atmospheric river event (which affected a relatively narrow region just north of the Bay Area) and a strong winter cyclone (which affected much of Southern California later in the winter).

A beautifully well-defined winter storm brought significant precipitation to Southern California late in the winter. (NOAA)

A beautifully well-defined winter storm brought significant precipitation to Southern California late in the winter. (NOAA)

There were a couple of additional minor precipitation episodes in addition to these, but for the most part, California saw nearly all of its precipitation during Winter 2013-2014 over the course of these two storm systems. So while winter 2013-2014 ultimately came in as “merely” the third driest in the past 118 years, it immediately followed what was (by far) the driest calendar year on record in 2013. And, as it turns out, 2012 was also drier than average on a statewide basis (though not nearly as dry as 2013 or 2014). Thus, the present event now includes 3 successive dry years, and includes the driest year in over 100 years (and perhaps since California’s statehood).

 

Into the frying pan

As California’s long-term precipitation deficits have skyrocketed over the past 18-24 months, another dramatic trend has become increasingly apparent: an extraordinary string of record-warm days, months, and multi-month periods. Most notably, California experienced its record warmest winter in 2013-2014, and (as of June 30th) is currently experiencing its warmest year on record to date. Even more remarkable is that these recent temperature record have been broken by a very wide margin–2014 so far has been more than 1 degree warmer than the previous record warmest year. This record-shattering warmth has serious implications for the ongoing extreme drought, since warmer temperatures result in greater evaporation (and evapotranspiration). This means that an even lesser fraction of the already record or near-record low precipitation was actually available to plants and ecosystems–or as rain/snowmelt runoff into California California’s rivers and streams.

California is experiencing its record warmest year to date as of June 2014. (NOAA/NCDC)

California is experiencing its record warmest year to date as of June 2014. (NOAA/NCDC)

 

Just how severe is the ongoing drought in California?

This combination of exceptional dryness and record warmth have acted in combination to produce the most severe drought conditions experienced in California in living memory (and very probably over a century). The Palmer Drought Severity Index (PDSI) is an aggregate metric of long-term (meteorological) drought severity–which takes into account observed precipitation, temperature, and soil moisture–and is widely used to characterize the intensity of drought conditions. The PDSI is a normalized metric, with a scale ranging form +6 (wet) to -6 (dry), and any value lower than -4 is considered to correspond to extreme drought. At the present time, a large fraction of California is experiencing literally chart-topping PDSI values less than -6. These values–both regionally and on a statewide average basis–are higher than at any other point since at least 1895, according to the latest NCDC rankings. From these data, it’s entirely reasonable to assert that the present drought is already more intense than any 20th Century drought in California.

Another interesting aspect of the present drought is to note the temporal structure of the large positive temperature anomalies California has been experiencing recently.

Daily maximum temperatures in 2014 have been higher than any other year on record. (NOAA/NCDC)

Daily maximum temperatures in 2014 have been higher than any other year on record. (NOAA/NCDC)

Daily minimum temperatures in 2014 have been higher than any previous year on record, though not by as wide a margin as daily maxima. (NOAA/NCDC)

Daily minimum temperatures in 2014 have been higher than any previous year on record, though not by as wide a margin as daily maxima. (NOAA/NCDC)

One of the most striking features in California’s temperature record is the presence of a distinct long-term trend, on the order of +0.2 degrees per decade since the late 1800s. This trend is present in overall temperature, daily maximum temperature, and daily minimum temperature, but the increase has been largest in daily maximum temperatures, which have increased by over 1.4 degrees F since 1895. Interestingly, the temperature anomalies in 2014 have closely mirrored this overall trend, with all-time records set for both daily minimum and daily maximum values but much larger anomalies occurring with daytime maximum temperatures.

A long-term trend also exists in PDSI values for California, which has trended toward lower values over the past century or so. Interestingly, there have been no statistically significant trends in California mean precipitation over this same interval, which suggests that the strong warming experienced in California is likely responsible for the increasing drought severity. I’ll have a more extensive post on the role of climate change in the current California drought (and the RRR pattern) later this year.

Recent PDSI values are the lowest on record for California. (NOAA/NCDC)

Recent PDSI values are the lowest on record for California. (NOAA/NCDC)

 

Impacts of the extraordinary 2012-2014 California drought: Where we stand now

All 58 California counties have now been designated by the federal government as primary natural disaster areas due to the drought. A state-level Drought Emergency has been declared, and state authorities have recently taken unprecedented measures to cope with dwindling water supplies. National and international media attention has become increasingly focused on this ongoing extreme climate event in California as economic damages to date surpass $2 billion, and continues to rise rapidly. Increasingly broad swathes of farmland are being fallowed in the Central Valley (especially the San Joaquin Valley), and entities with access to remaining water are auctioning off their rights for over ten times the long-term average rate. Groundwater pumping has increased exponentially over the past 12 months, and there are growing concerns that this virtually unregulated draining of California’s underground aquifers could have major major consequences within the next couple of years.

Just how low are California’s reservoirs right now? The figure at right shows that most of California’s major reservoirs are below 50% of capacity, and some are well below that meager level. More importantly, many of these reservoirs are near or below 50% of average capacity to date–which is especially remarkable since water levels are typically well below maximum capacity by this point in the summer. One big problem over the next few months is that the extreme long-term dryness–combined with enhanced human and “natural” demand due to record warmth–will allow reservoir levels to drop at rates greater than the long-term mean.

Current reservoir levels in California are low and dropping rapidly. (CA DWR)

Current reservoir levels in California are low and dropping rapidly. (CA DWR)

While last winter’s brief but intense precipitation during February and March prevented California’s reservoir levels from being catastrophically low this summer, many may start approaching record-low levels by October/November 2014. Some small communities in California are at risk of running out of water within the next 3-4 months, but much broader trouble may loom over the next 1-2 years without a series of wet to very wet winters helping to bolster supplies. Even Lake Mead–which is filled by the flows of the Colorado River and is a critical water source for much of Southern California–has dropped to record-low levels as of July 2014 (though it should be noted that these low levels are actually due to a much broader and longer-term drought across the American Southwest).

California’s wildfire season has gotten off to a rather ominous start, beginning with the off-season Northern California fires in January, followed by the destructive San Diego-area fires driven by unusually strong Santa Ana winds in May, and has recently continued with unusually intensely-burning fires in Northern and Central California despite the relative lack of extreme weather conditions usually required to sustain such extreme fire behavior.

Fuel moistures and energy release components (ERCs) in vegetation are near or exceeding record levels (the Mid-Coast region is shown here as a representative example). (NorCal GACC)

Fuel moistures and energy release components (ERCs) in vegetation are near or exceeding record levels (the Mid-Coast region is shown here as a representative example). (NorCal GACC)

In fact, several special fuel and fire behavior advisories have recently been issued for much of California due to record-low fuel moistures and potentially explosive wildfire behavior in the coming months. While there has been a relative lull in fire activity across California in recent weeks, current events in Washington and Oregon likely foreshadow a very severe fire season to come in California. Many in the firefighting community are anxiously awaiting the development of extreme fire weather patterns over the next several months–such as dry lightning outbreaks, extreme heat waves, or strong offshore winds–which nearly always occur in California between August and October.

 

What does the (near) future hold?

The shortest (and, unfortunately, most accurate) answer to this question is: we simply don’t know. The rest of summer will probably continue to be warmer than average, and associated impacts (namely, extreme wildfire conditions and low limited water availability) will continue to grow more acute until that start of the next rainy season during winter 2014-2015. There has been much speculation regarding the likely El Niño event this year and its possible role in alleviating drought conditions in California. I’ve already written extensively on both the development of the present El Niño event specifically and the more general impacts of ENSO upon California precipitation. The quick summary version: connections between California precipitation and El Niño are rather tenuous, except for very strong El Nino events, which are associated with increased cool-season precipitation. This is especially true for inland regions of Northern California, where the majority of California’s reservoirs and “snowpack stored water” capacity resides. While there were some early indications during spring 2013 that the upcoming likely El Niño event could be a very strong event,  a top-tier event now appears less likely.

Therefore, while there was never a high chance of El Niño breaking the current California drought, there is now an even smaller of a chance of that happening. We still don’t know how strong El Niño may be, nor how much precipitation California will experience next winter (regardless of what happens with El Niño). There are some indications in the long-range seasonal forecast models that some substantial precipitation may occur during DJF 2014-2015, but such projections are subject to very high uncertainty (especially in light of the uncertain evolution of conditions in the Eastern Pacific). And–as Mike Dettinger has pointed out–it’s quite likely that California’s drought will persist through next year even if we have a relatively wet winter. While a wet (or even near-average) winter would help alleviate some of the most acute short-term effects of the drought, many parts of California have missed out on nearly a full year’s worth of precipitation, and it will take a long time to gain back that deficit even in a best case scenario.

In the meantime, California’s long, dry summer continues. Stay tuned.

 

© 2014 WEATHER WEST

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  • Ian Alan

    Solid cloud deck today that has been thickening up since sunrise and coming from the east – low clouds starting to form, humidity up to 63 from 40 this morning and dew point at 57. Temp dropped to 69 from a high of 76 at 9am.

  • Ian Alan

    Looking west, essentially same view

  • lightning10

    My area has a 40% chance of thunderstorms for tomorrow. That is the highest chance since last year in August where thunderstorms hit in the afternoon started in Whittier and ended in Pasadena.

    • Dan the Weatherman

      Orange County has the same probability for tomorrow as well. Hope we all get something!

      • Kamau40

        What you guys are getting in So. Cal is a very nice juicey air mass along with great vorticity max. There is some suggestion from a couple of the models that some that moisture may make it as far north as Santa Rosa by Mon. There is a small cut off low of the Ca. coast combined with the already established 4 corners high that could help push some of that moisture up in Nor. Cal within the next 24-48hrs. I’m already seeing some of the high clouds drifting up from the S.E. I think it is something that needs to closely be monitored, especially in light of high active the moonsonal season has been in Ca. during the past month.

  • Ian Alan

    Some thunder and rain started – looked up and this cloud formation greets me.

    • Xerophobe

      nice shots!! i really like the bottom one

  • Ross Mccorkle

    Two rain showers 45 minutes apart in San Clemente.

  • Guest

    2/100ths of an inch this AM! I’ll take it. Interesting sky, too. Looking forward to more!

  • sdmike

    2/100ths of an inch this AM! Interesting sky, thunder and lightning, more to come!

  • sdmike

    Photo that was MIA from last post.

  • Dan the Weatherman

    I am hoping to see some shower and thunderstorm activity here in Orange. So far, it just has been cloudy and muggy, but it looks as if it might rain.

    • sdmike

      Looks like it’s slowly creeping your way. Maybe tonite or Sun?

  • lightning10

    Nothing here in Whittier yet. Sure hope they dont lower the pops for tomorrow.

  • Bandini

    Line of storms parading into the Kingman Arizona area looks mighty impressive. Mammoth already has cells blossoming above as well, hopefully they make it a little west for fire help. You can really see how smoky they are on the cams.

  • lightning10

    I would hate to see this turn into a mostly light to moderate rain event. That is what I think it could become. When cloud tops cool tonight it will be interesting to see if we get more lightning.

    • stormsurge10

      Weird. My neighborhood down here in SD saw some nice looking rain that lasted 30-60 minutes, somewhere before noon.

  • Dan the Weatherman

    It has been cloudy all day here in Orange and has looked as if it is going to rain, but so far I haven’t seen a single drop.

    • I am the white devil

      Where did this rain originate? Easterly wave or e. PAC storm reminants

      • Dan the Weatherman

        Monsoonal moisture and a low that came up from central Baja (somewhat like an easterly wave), which provided the dynamics for rainfall west of the mountains.

  • lightning10

    I would guess that LA and part of Orange county has been under subsidence all day.

  • lightning10

    Just like that pops have been lowered. Sounds like to many clouds and it not being warm enough might kill the day.

  • redlands

    Redlands, Ca ended its 87 days in a row with no rain streak today — as of 812pm August 2 – 2014 Redlands has receive 0.06 of rain . The high rain rate of 0.07 happened at 144pm today – with a wind gust of 14 mph. Hi today was 90.5 at 1116am – low of 67.8 at 455am – present temp of 74.4 humidity 88% — hi dew point of 71 at 8:04pm –was raining very lightly few minutes ago — I sure hope this isn’t all were gonna get —— Any other people get rain and their amounts and locations. Was really nice to see/feel the storm a brewing — wish it gets stronger

  • Dan the Weatherman

    Light rain is continuing to fall here in Orange this evening, and has become noticeably more humid after it started about a half hour ago.

  • so.cal.storm.lover

    I went to a park earlier today in Temecula after 3 hours straight of rain and the water was about 2 feet deep in an area. And when the low approaches tonight all areas will start seeing shower/thunderstorm activity so hang in Dan the weatherman. Also I believe someone said they wanted the storm to strengthen it is. And lightning10 the cloud cover… No problem the lift is more than enough to over come that.

    • Dan the Weatherman

      The latest AFD out of San Diego tonight was saying the same thing about the lift, since the precipitable water (PW) was so high for this area. There is even a Flash Flood Watch in effect for all of San Diego County from late tonight through Sunday. Excerpt from AFD:

      LOTS OF POTENTIAL HERE…EVEN WITH LIMITED DAYTIME HEATING BECAUSE OF THE ANOMALOUSLY HIGH PW…SATURATION OF THE AIRMASS…AND WEAK FORCING NECESSARY TO GENERATE SUSTAINED LIFT. NAM DOES NOT GENERATE
      MUCH MU CAPE THROUGH SUN. LOOK FOR…SUSTAINED UPSLOPE FLOW… SYNOPTIC CONVERGENCE AND POSSIBLE CONSECUTIVELY DRIVEN OUTFLOW BOUNDARIES TO TRIGGER AND MAINTAIN SHOWER DEVELOPMENT. IT WILL BE DIFFICULT TO TELL WHERE AND WHEN MUCH OF THIS MOISTURE WILL GET
      SQUEEZED OUT…BUT THE BEST CHANCE WILL BE ON THE MOUNTAIN SLOPES AND ADJACENT VALLEY AND DESERT FOOTHILLS AREAS. BUT GIVEN THE ANOMALOUSLY HIGH PW AND TRACK OF THE MID/UPPER LEVEL LOW ACROSS COASTAL SAN DIEGO COUNTY…THERE IS JUSTIFICATION THIS TIME AROUND
      TO EXPAND THE WATCH WESTWARD TO THE COAST FOR SUNDAY GIVEN THE THREAT.

      • so.cal.storm.lover

        Yep tonight and tomorrow should be interesting. Also the add says there is a good chance of a mesoscal convective system developing tonight over lower Colorado rice and making possibly all the way to the coast…so I’m rain dancing.

  • Kamau40

    The latest local models here in the Nor. Cal is now considering to adding the possibility of showers/thunderstorms over the next several days because there is so much deep moisture coming up. Could be some interesting weather coming early next week. Stay tuned.

  • Unbiased Observer

    It’s raining at Dodgers Stadium, looks to be a bit more than a sprinkle at this point

  • Ian Alan

    After a measly .02″ this afternoon the clouds continued to thicken and a light steady rain starting around 730p has slowly turned into a more moderated rain and sitting at about .25″ since 745p and a temp of 57F. Feels more like an early fall ‘storm’ except the clouds came in from the wrong direction. lol

  • Dan the Weatherman

    After some light rain, it has lightened to sprinkles, but the cloud deck appears to be lower than it was earlier, so that could be good news for more substantial rain later tonight as more of the air column is saturated.

  • Kamau40

    Here is the latest statement for Nor. Cal late this evening discussing how all of this substantial moisture surge could impact our weather early next week:

    Discussion…as of 9:05 PM PDT Saturday…marine air swept inland
    more vigorously today than anticipated…especially in the sf Bay
    area where high temperatures today were as much as 15 degrees
    cooler compared to Friday. Robust onshore flow continues this
    evening and recent trends from The Fort Ord profiler indicate the
    marine layer is deepening past 1500 feet. Thus…expect more
    widespread low cloud development across inland areas
    tonight…later clearing on Sunday…and continued cooling for
    inland areas on Sunday…especially for the warmest inland
    valleys. A forecast update was recently completed to decrease high
    temperatures for tomorrow and Monday.

    An interesting weather event is underway tonight over Southern
    California…something that may ultimately impact our area by
    early next week. A weak cyclonic circulation center is currently
    centered near San Diego…along with a very moist airmass. The 00z
    San Diego sounding shows precipitable water values that are very
    high for this time of year…at 2.16 inches. By tracing the
    circulation center back in time…it can be seen that this weak
    system originated along the coast of western Mexico near Puerto
    Vallarta on Monday and has been gradually drifting northward since
    then. This would explain the high moisture content of the airmass
    currently over Southern California. The big question now is where
    this system and its subtropical moisture will track over the next
    several days. The 00z NAM forecasts the low center…currently
    near San Diego…to lift slowly north to the southern San Joaquin
    Valley by tomorrow evening and then take on a more northwesterly
    bearing and move to near the Sacramento Delta by late Monday.
    Initially…most of the deep subtropical moisture associated with
    this system will remain to our east…but the 00z NAM then wraps
    moisture around the low center and across the eastern edge of our
    forecast area by late tomorrow and tomorrow night…then across
    the North Bay by Monday night…and eventually across nearly all
    of the sf Bay area by late Tuesday. The 12z European model (ecmwf) is similar…if
    only a bit slower with this process. Have added a slight chance of
    sprinkles to portions of our area through Tuesday…mainly eastern
    and northern portions. Will also need to consider higher rain
    chances given the amount of moisture available. Thunderstorms may
    also be possible…but instability looks marginal at this point.
    Also…the GFS keeps nearly all of the significant moisture to our
    east which adds some uncertainty to the forecast at this point.
    But the upshot is that our area could see some interesting weather
    early next week with potential showers and even isolated
    thunderstorms. Stay tuned.

    &&

    Aviation…as of 5:30 PM PDT Saturday…the marine layer is
    approximately 1200 feet deep. The onshore winds will usher in
    stratus clouds overnight.

    High cloudiness continues to edge north over the southern forecast
    area well north of a tropical rich air mass and circulation center

  • Dan the Weatherman

    The rain has once again picked up here in Orange during the last few minutes and it is the heaviest that I have seen so far tonight. It has mostly been alternating between sprinkles and light rain ever since it started earlier this evening. I haven’t seen any lightning as of yet, and I have been keeping my eye on the sky tonight to see if any develops. It is definitely warm and muggy tonight with the tropical air mass in place.

  • Utrex

    A combo of t-storms and showers will push through Nor. Cal. Monday through Tuesday, even bringing a threat of inland storms as well.

    Speaking of the rare event, remember that forecast for way above precipitation totals for August for all of California? I’m thinking that may take effect…

    • Zepp

      It sounds like Dodger Stadium got about a 1/4″ of rain, based on the incredulous remarks Rick Monday was making, which out put them well above average for the month of August. It doesn’t take much, really. Even up here, in August .25 inches is above normal for the month.

      Fires everywhere up here, and while we’re in a locations away from the worst of them, our skies are filling with smoke.

  • inclinejj

    Was watching the Dodgers vs Cubs came in SoCal last night. It was raining pretty good in extra Innings I guess it was around 10 to 10:30.

  • xeren

    Is the storm done for so cal? It looks like the system has swung north already, but I have no knowledge in this area

    • Looks like convection will probably fire just about everywhere later this PM across SoCal.

      • C M

        Can you send some up to San Jose as well? I would love to see a good light show? How’s the El Nino coming along?

        • I don’t believe it is related to the possibility of El Nino. I’m in San Jose also and we pretty much had high clouds. Models are all over the place with these types of weather systems recently. We will see what happens…

  • lightning10

    I don’t see why everyone is being so optimistic today. A lot of haze/clouds, temps are running 10-20 degrees below average, and instability parameters are fair at best.

    • Blaze202

      There are actually pretty good cloud break occurring right now. I think that bodes well for something to fire up across the area.

  • rob b

    In the northern part of the state we can only hope if we do see T-Storms that they are wet. Sounds like fire resources are very thin, North Ops in Redding is at level 5 on a scale of 1-5 basically everything available is assigned and they are asking for more. I know many Cal Fire stations are now being filled by local Gov’t crews, I was driving along 80 yesterday and noticed a contract dozer staged in Auburn at the Cal Fire offices there.

    I had read and heard reports of dry lightning possible mon/tue on the Western Slope of the Sierra, that area has seen many large fires recently. Hopefully those storms include plenty of moisture in them.

  • Dan the Weatherman

    It has been very humid here in Socal since yesterday. Dew points are in the upper 60’s to low 70’s as of noon today in much of coastal Orange and San Diego Counties. Here are a few examples of current temperatures (T) and dew points (D) for selected cities in the region as of noon: Santa Ana: T 83 D 73, Fullerton T 84 D 69 Laguna Beach T 76 D 71 San Diego Limbergh T 74 D 67 Temecula T 78 D 72 and Huntington Beach T 76 D 71.

    • Sunchaser

      Very humid here in south east part of Glendale as well. Running at 70 – 73% ….Had about .03 of light rain last night which was enough to get the pavement wet and that’s about it….Hope all this interesting weather leads us to a wet fall/winter…

      • Dan the Weatherman

        I hope this all leads to a wet winter. This summer definitely has that “El Nino summer” feel to it like the summers of 1994 and 1997 did.

  • lightning10

    I think the last time dew points where this high where mid July of 2006. Also new models show there might be some hope for the valleys before sunset for T-storms. The sun has fought its way through.

    • Dan the Weatherman

      I remember that period in late July, 2006 and it was very hot and humid. That episode ended with a thunderstorm over my area that dropped between .25″ and .33″ in which the lightning was very close to here. There was a very loud clap of thunder that set off the car alarm. Around that same time a brush fire was started by lightning on Catalina.

      • lightning10

        I have some video. I remember several nights of lightning in June and July. In June also a wild night where we had a very strong microburst her in Whittier.

        I think for later on for south eastern la county and Orange county I would expect outflow to help the cause for some more showers and thunderstorms in this area. As the sun has been out.

  • craig matthews

    Sure looks like someone down there getting thunderstorms with heavy rain from vis satellite perspective. Very impressive!

    • Kamau40

      Those are some VERY impressive convective cells in So. Cal.

      • Dan the Weatherman

        There is a Flash Flood Warning in effect until 5 p.m. in the eastern San Gabriel Mountains in Los Angeles County, and this includes the Mt. Baldy area.

        • craig matthews

          Those clusters of Thunderstorms look like they are almost stationary over San Gabriel Mtns and San Bernardino Mts. Must be some flash flooding up there

          • Dan the Weatherman

            The Flash Flood statement mentioned that those storms were nearly stationary.

      • craig matthews

        Looks like the sun broke through enough to get things going today, at least over what appears to be San Diego and San Bernardino county areas. I hope this makes it to norcal like some of the models are showing now.

  • TheNothing

    It’s nice to see you guys down there getting some action, I just hope we get a little up here too.

  • Kamau40

    Looking at the latest models, they are still split on where the deep moisture surge will go. The GFS model keeps the moisture east of the Nor. Bay on Tue. However, the NAM model is still very bullish in curving the deep moisture westward Tue/Wed right into the S.F. Bay Area including many portions in the Nor. Bay.

    • craig matthews

      Kamau40, I posted a GFS model output above. A rather complex pattern evolving over/off CA in which models have a hard time with how the low moving ENE from the pacific is going to react or merge with the subtropical low as it moves north out of Socal.

      • Kamau40

        Yep, I saw both models earlier. I will take another look tomorrow. If you look at the NAM models though, it is much more aggressive of curving the moisture right toward the Bay Area and much of Nor. Cal by Tue thru late Wed. The NAM has been more accurate lately in projecting how sub-tropical moisture will move compared to the GFS models.

        • inclinejj

          Kamau40 Where are you located in the North Bay?

          • Kamau40

            Between Napa and Calistoga. How about you?

          • geopower

            He’s in Incline Village

  • craig matthews

    18zGFS 6 hr precip forecast for Tuesday. This is an impressive early August precip forecast for the northern sierra/parts of Norcal for Tuesday. Sure is nice to see parts of this parched state getting some relief, albeit temporary, and not a drought buster by any means.

  • Ian Alan

    Only trace amounts of rain today and while I had given up hopes of getting the forecasted 1″-3″ rain the rain has picked up right now and thunder in the distance…..forest falls to the south is getting hit hard as well as wright wood area to the west – massive complexes in the desert to the east…..can’t something drift this way geeze it’s all around me lol

    • Dan the Weatherman

      Maybe you will pick up something early this evening before it ends later.

      • Ian Alan

        Sure did – another .25″ as shortly after I posted the skies opened up, no hail but a very soaking rain @ 57F and an odd thing, dense fog rolled in and stuck with us, never saw that in the summer before.

  • lightning10

    Looking rather threating here in Whittier over the past 30 min.

  • lightning10

    Here is a real time lightning tracker

    http://www.lightningmaps.org/realtime?lang=en

  • Dan the Weatherman

    I picked up .03″ last night here in Orange, which is the first measurable rainfall here for the 2014-15 season. There hasn’t been any rain here today, but the sky looks darker to the east and northeast, so there still might be a chance of something this evening before things wind down.

  • Dan the Weatherman

    It appears that some cells have developed to the east and southeast of my area here in Orange and the clouds are looking much darker than they have for much of the day. I can’t quite tell which way they are moving, but the cells look to be building a bit more to the west. I will certainly be on the lookout for lightning and I hope to get a bit more rain here tonight.

  • Judith Blakely Sanders

    It was just wonderful here in the IE ,when we got an almost steady rain yesterday, and a bit more today,…but I realized just how long its been ,looked at our nearly blackend field by our house, …This sure is frightening, ..praying for more rain!

  • Kamau40

    It looks like we could see some activity up here in Nor. Cal starting late Mon and lasting into at least Tue. Models are more in an agreement with overall synoptic weather pattern to bring in the possibility of showers/thunderstorms from the huge moisture surge coming up from So. Cal. The precipitable water values are also very high for this time of year. Here is the updated statement from this evening:

    Area forecast discussion
    National Weather Service San Francisco Bay area
    848 PM PDT sun Aug 3 2014

    Synopsis…showers and thunderstorms will be possible beginning
    tomorrow lasting through at least Tuesday afternoon. The best
    potential for this threat will be from the Santa Cruz Mountains
    and Santa Clara Valley north into Napa and Sonoma counties.

    &&

    Discussion…as of 8:48 PM PDT Sunday…plenty of low clouds
    around the forecast area this evening with many local airports
    reporting overcast skies this hour. The current infrared satellite image
    is showing high clouds moving over California with plenty of
    lightning strikes over Southern California. The satellite/GPS
    derived total precipitable waters is showing nearly 2 inches of
    tpw over Southern California. This moisture is expected to move
    into our forecast area on Monday.

    The 1200z European model (ecmwf) and 1800z gfs40 have initialized well with the
    current synoptic pattern. Both models slide a low pressure system
    up from Southern California into central California/western Nevada
    Monday. As this low slides northward it advects abundant moisture
    into our forecast area. This moisture combined with modest amounts
    of instability will result in a possibility of showers and
    thunderstorms Monday into at least Tuesday afternoon. The best
    possibility of showers and thunderstorms will be from the Santa
    Cruz Mountains and Santa Clara Valley northward into Napa and
    Sonoma counties.

    Forecast soundings for koak are indicating precipitable water
    values of 1.5 to 1.75 inches Monday evening into Tuesday morning.
    This amount of precipitable water is well above what we typically
    see in central California this time of the year. Therefore…expect
    any thunderstorms to be wet tomorrow with this event. Keep in mind
    that there is always a possibility of lightning striking outside of
    the thunderstorm rain shaft…potentially sparking a fire. One
    other possibility with these thunderstorms will be ponding on the
    roadways due to clogged storm drains.

    • craig matthews

      Yup, looks like a Bay Area and points north event right now. GFS has recently shifted in a more NAM direction as far as how the pattern is to evolve next 24-48 hours. Looks like Monterey county going to get missed by this one. But I am so happy to see many areas of CA getting wetting rain in August.

      • Kamau40

        Absolutely!! If you notice, we have not had this type of weather pattern in Ca. during the last 3yrs. There are signs we may see more monsoonal and subtropical events for the state as we go further into Aug. In looking at some of the long range models, some of the dates that bears watching are Aug 19-20 and 25th. Yet, another large 4 corners Continental High pressure cell may set up in the right position which may mean more moisture surges. The pattern is totally different this Summer. We have also been having some good marine layers along the coast. This time last year, it was nothing but blazing sunshine and hot temperatures and no moisture surges extending this far westward.

        • craig matthews

          Seamed like focus of monsoon surges last summer were further east over the sierra and Nevada deserts. This year the focus is further west, over California. This summer in some ways reminds me of the summer of 1991 where I live. But this summer is more active so far.

          • Kamau40

            Exactly. The monsoonal surges were much further east over the Sierra and Nevada deserts this time last year. We have seen I believe we have seen IV monsoonal surges over the past month extending all the way out to Ca. so far. If the long range models are correct, there is more to come down the road. We may see the next moisture surge(# 5) coming up along the Sierra mountain range maybe next Tue or Wed of next week. Daniel Swain mentioned in an earlier blog that he sees more possible opportunities for moisture surges statewide down the road. Do you see more hints of activity down the road too?

        • Dan the Weatherman

          This is definitely looking like an El Nino summer to me and the high humidity reminds me of some good El Nino summers of the past: 1994 and 1997 especially. The western ridging, higher humidity here in Socal from the warmer SSTs off our coast, Midwestern troughing, an active monsoon, a good deal of tropical activity in the eastern Pacific with Iselle possibly affecting HI later this week. An less than normal Atlantic hurricane season is also a feature of an El Nino year, but despite only two storms so far in the Atlantic basin, it is still too early in the season to call it below normal as of yet because the Cape Verde season is just getting underway which provides a good deal of the action in the Atlantic from August until the end of September.

          • Kamau40

            I totally agree! I remember the summers of 1994 and 1997 very well. The overall weather patterns in those years were very similar to the weather conditions we are currently experiencing this summer here in Ca. The following Fall/Winters of those years were also very wet!!!

  • Bandini

    She’s taking her time marching north. Glad to see my brethren in So Cal get some good rains. My buddy was out near the Ord mountains today and spoke of some fantastic storm cells.

    • so.cal.storm.lover

      So am I!

    • rob b

      Looks like Tahoe and Truckee have had rain all day, nice to see hopefully we’ll see some water return to the Truckee River.

      • Bandini

        It’s very wet out.

      • I was up at Sonora Pass yesterday and there was soaking stratiform rain for a few hours. Very strange for early August, but certainly not unwelcome in that area.

  • Pingback: Rain in Southern California - Ann About Town()

  • redlands

    Redlands,Ca – Weather Update Redlands has finally gotten to join the summertime rain club !!!! August -2 – 2014 — Redlands received 0.12 – to end a 87 days in a row with no rain streak. — August – 3 – 2014 we received 1.28 of rain – with a High Rain Rate of 5.28 — yes 5.28 — that’s how hard the rain was coming down , along with thunder and lighting. Hi Dew point of 72 — wind gust of 13 mph. So we got 1.48 of rain for the 2 day total — Would have to check , but I think this puts us at my station — the 2nd wettest August — Anyone else get a good soaking ???

    • Ian Alan

      Nice! I only heard the thunder and recieved a two day total of .52″ while just up the road in rimforest and lake arrowhead areas received up to 3″ and more.

  • craig matthews

    Weather pattern getting a little more complex off CA coast as the upper level low far to the west of Point Conception tries to draw moisture with the sub tropical low now moving up sierra westward across Norcal next 24 hours.

    • Kamau40

      It is getting more complex. Right now there are lots of high & middle level clouds and very breezy conditions up here in Nor. Cal. We’ll be watching things closely over the next 24-48hrs, could get interesting!

  • alanstorm

    Really happy for everyone in the parched So Cal, Ariz, Nev & Sierras getting RAIN! What a blessing. Not a drop yet here in Mendocino Co, but this overcast is a welcome break to a Hellish 2014 summer. Just finished 8 consecutive days of over 100? with 3 of them being around 104?. Here, its all about fires, we have several burning, but nothing major yet. Fire planes flying to & fro, water trucks delivering everywhere as pot growers are out of water, & last night a bear visited my neighbor’s pond, no doubt coming out of the highlands with all the other critters looking for water. My fear is tomorrow’s predicted rain showers will have lightning. Being the driest anyone has ever seen here, plus the daily afternoon winds that come out of nowhere, a light rain event could spell catastrophy here.

  • Xerophobe

    Here’s a TPW forecast for tomorrow. Good site to take a peek, too.

    • craig matthews

      Been trying to find this TPW site W. West posted last week. Thanks.

  • David Thomas

    This has been more of a fall like storm with rain most of the day N of i80 with a few showers S. This is what you would see durning the fall and winter and not in the mid two late summer. T storm today have been a bust for all areas thanks two Clouds cover and rain up N. I would. Say that today event for the N would be the 1st rain of the season All. So sac is looking at RECORD high low for today with. Things being so cool. All so I think with all the cool air we have in the valley and mts I think snow levels have fallen two the highst. Peaks I wounder if there been any snow reported. With all the rare valley and my rain we have had today

    Like I said. Today event is more of. A fall/winter. Storm. Then a monsoon. Evnt

    • inclinejj

      Mt Rose had a bit of white on the top the other day. Don’t know if it was snow or hail.

  • Ross Mccorkle
    • geopower

      Since it was cloudy and raining in Death Valley Sunday, I’d guess evaporative cooling is what gave them such a relatively low high. Or, maybe all the commenters are right about this “data” refuting the MSM conspiracy to promote MMGW. Which is why it’s published in the Post.

      http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=vef&sid=ISWC1&num=72&raw=0

    • Coincidentally, I happened to be in Death Valley on Sunday–the coolest August afternoon there since the 1980s. It was cloudy all day, and there was a stratiform rain for much of the day! Truly a strange weather pattern in all corners of the state.

  • Utrex

    Unusually high instability levels are noted in the NAM for Tuesday afternoon / evening for inland valley areas. Moisture is quite limited, however if we get enough rain the moisture will be more than modeled. Looks like tomorrow will be when the thunderstorms actually arrive. (Monday night into Wednesday)

  • Bandini

    Couldn’t be happier. It has been raining nonstop in Truckee for 18 hours. Nothing intense, but a nice soaking rain, light to sometimes moderate and as someone mentioned below it feels much more like a fall storm in the Sierra than a typical monsoonal surge. My friend’s rain gauge in downtown shows 1.14 and it is still coming down. This thing has been focused right over us.

    • rob b

      Looking at The Weather Channel forecast they show a chance of rain each day through Saturday in the central Sierra! Not great for the tourist business this week, but long term could be really good news.

  • Kamau40

    Looking out to the East this evening here in the North Bay, I see lots of dark clouds slowly moving in.

    • craig matthews

      Radar shows some yellow’s heading your way from the east-northeast. Have fun!

      • Kamau40

        It is actually raining a little bit. Nothing heavy, but it feels soooo great to finally feel and get some extremely badly needed moisture.

        • Dan the Weatherman

          Have you seen any lightning in your area tonight?

          • Kamau40

            I did not see any lightning this time in my area, but it was awesome to finally see the first light rain of the 2014-15 rain year. Given the fact this is happening in Aug here in Ca. is very exciting and perhaps a promising sign of things to look forward to later in the year!

  • Zepp

    We’re finally getting significant rain here in McCloud! Fairly rambunctious lightning, knocked out the power in town, and now a strong steady downpour. It’s wonderful!

    • Dan the Weatherman

      At least you are getting heavy rain with the lightning as opposed to dry lightning. Hopefully any fire starts caused by the lightning are getting doused with the rain!

      • Zepp

        That’s my hope. When I got up, I took a long, careful look around. It’s not smoky, and doesn’t smell like smoke. It’s overcast, and I think more rain is in the offing. We got .15″ last night.

    • alanstorm

      Man. That must be nice. Hope it soaks things up good for you. Luckily its a slow mover. Nothing here yet, but I’m waiting…..

  • Dan the Weatherman

    There was flash flooding yesterday in the San Gabriel Mountains and other mountain areas of Socal. One man was swept away by the flash floods in his car in the Mt. Baldy area and died. About 2,500 residents were stranded in Forest Falls and Oak Glen because debris flows washed over the roads into those areas and people couldn’t get to or leave the towns.

    • so.cal.storm.lover

      That’s sad a man died.

      • Dan the Weatherman

        Apparently the car was swept away by the raging floodwater and overturned, and his body was discovered inside the vehicle later.

        • xeren

          The article I read about that claimed baldy got 5″ of rain

          • Bandini

            I heard that too, any confirmation?

          • xeren

            none that i’ve seen. it possible, i guess, since baldy picks up more snow than the surrounding areas in the winter

          • xeren
          • Bandini

            Thanks! Man that is wild. I spent a lot of time in the Cucamonga Wilderness and hiking up Old Baldy in the past and I’ve experienced some fun weather up there, mainly snow. That is an astronomical amount of rain for such a short period of time. There have been cells up here lately with some high rain rates and insanely big drops but it is hard to imagine 3.98 inches in an hour!

          • Xerophobe

            Here’s a seven day total. It’s quite possible that somewhere nearly received as much as 5″ This shows over past 7 days, There was almost 3.5 inches reported the past two days at Yucaipa ridge (i’m assuming that’s close to Mt Baldy?)

          • Ian Alan

            Yucaipa ridge is not close to mt. Baldy it’s close to mt. San Gorgonio in the San bernardinos. 40 miles apart or so as the bird flies. It’s the same thunderstorm responsible for the heavy rains in Redlands and loma Linda as these areas sit below Yucaipa ridge, which goes up to 9000′.

          • Xerophobe

            Thanks for the pointing me in the right area!

          • Ian Alan

            I should also mention, Forest Falls is in a unique location that caters to summer thunderstorms and heavier winter rainfall, mud and rock slides is the norm and if you ever go there you’ll see why. It’s a community in a narrow mountain canyon starting at 4k and rising over a few miles to 6k. On the east it quickly rises to 10k and 11k feet to the San Gorgonio wilderness and on the south and east rising quickly (like a cliff) to Yucaipa ridge which then falls quickly to 1000′ in the valleys to the west.

    • Kamau40

      Very sad story indeed. Our hearts and prayers goes out to his family.

    • craig matthews

      There might have even been a few isolated places that picked up more rain in a few hours then what they had all of last winter! Some of those stationary thunderstorms produced rain rates in excess of 5 inches an hour according to some earlier posters. But while it is fun to watch, hearing the sad news that someone died from this intense thunderstorm is quite a punch to the heart.

  • Bandini

    Rain has really picked up the past 30 minutes. It has officially been raining for 24 hours now and the radar is still cranking.

  • Joseph B.

    A nice steady rain now in Martinez. So exciting I can’t sleep! Can’t believe it’s August.

  • xeren

    http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/anim/wkxzteq_anm.gif

    August 1st – here comes another kelvin wave!

    (you may have to click the link to see the aug 1 image)

    • Xerophobe

      Thanks! nice to see there seems ot be some support from as far ‘east’ as Indonesia hooking up with the warm pool over New Guinea. It seems to stretch from Indonesia to the Solomon’s, now. Also in the last frame it also appears that the cool pool is dissipating as well.

      • craig matthews

        Thanks Xeren and Xerophobe. It sure looks like that new warm Kelvin wave is organizing, and increasing in size and temp as well. SSTA’s are beginning to drop in the far western Tropical pacific and in the area between Darwin and Indonesia. And SSTA’s are increasing near the dateline. So hopefully this possible increasing west to east SSTA gradient will cause the atmosphere to respond and become coupled with the ocean to give the push that is needed for a true El Nino. But we still don’t know for sure if that is really the reason why this El Nino is taking longer to develop. Though its a good theory. Have you heard any news on the IOD?

        • Xerophobe

          I was going to look more later today. I think warm water between the Horn and India and cool water between India and Indonesia is the optimal set-up for supporting El Nino. I’ve notice cooler water above Indonesia recently and at least something around the Timor Sea (between Oz and Indonesia). I think the atmosphere will hook-up somewhat for awhile if the trend continues. As we are seeing water temps can change a lot in a month or two.

        • Xerophobe

          Craig, here’s something to keep you entertained re IOD. I didn’t have time to look at it today.

          http://www.jamstec.go.jp/frcgc/research/d1/iod/HTML/Dipole%20Mode%20Index.html

      • Kamau40

        Yep, I noticed that yesterday as we continue to monitor things out in the Tropical Pacific on a weekly basis. This looks like a very healthy and impressive oceanic kelvin wave developing.

        • craig matthews

          Indeed. The new Kelvin is really getting organized and increasing in strength right now. Should see a jump in upper ocean heat content soon from this new surge of warm waters. Been wondering if the odd development of this El Nino has something to do with time of year and the way seasonal oscillations are lining up with angle of sun over the ocean. Perhaps the warmer waters in the western tropical pacific have something to do with that as well. It appears that some El Ninos of the past tend to increase in strength right around the autumn equinox. This is just a thought with no scientific evidence to back it up.

          • Kamau40

            Yes indeed. I believe in light of the newly developing kelvin wave, the heat content should increase again by the end of the summer. You thought on the possible affects on the odd delayed response of the current still developing El Nino pattern is a good one, but I’m not aware either of any scientific evidence to back it up. Daniel Swain did mention, however, awhile back which makes sense too is the phase of the MJO. But, he said and so am I, is that we are still learning more in depth how the MJO phase work. Remember, the 1982-83 event, for example, developed late and so did the ocean and atmosphere response which did not get going until late Sep and Oct of that year.

        • Xerophobe

          It’s interesting to look at Nino 1+2 forecasts as well and it would seem from the CFSv2 as well as JAMSTEC (Japan) that this will be a central based event of possible moderate strength.

  • alanstorm

    Weird. Can’t remember when I’ve seen a rain event training east to west like that here. That thing has just been sitting in one spot spinning precip westward, total reverse of the norm cause of where that low is parked.Seems like I’m in a reverse rain-shadow being on a westward slope in Mendocino county. Not a drop here. The usually rain shadowed east slopes are getting all the rain, & its “training,”so should be good amounts for them. Come on rain, move my way! Chalk it up to another bazaar 2014 weather event.

    • geopower

      Yep, Reno’s had almost continuous gentle rain for the last 36 hours. It feels much more like typical West slope fall weather, and we aren’t complaining about it. Surface irrigation water for northern Nevada farms was shut off last week (2 months early) so these rains are saving a lot of crops and pasture. It’ll be interesting to see how this affects the gamebird populations, since they are usually limited by summer water and forage, and the last two years have been really rough.

  • So can we discount these rainfall quantities as spurious anymore? Looking at the GFS, the Sierras seem to be in for some rain for the next 96 hours or so. All that has to count for something, right?

    • xeren

      i’m not seeing any improvement yet

      http://weatherwest.com/wp-content/uploads/2014/07/water.jpg

      http://cdec.water.ca.gov/cdecapp/resapp/getResGraphsMain.action

      we need a lot more rain like this to really make a dent.

      • It’s very unlikely the recent/ongoing rainfall will result in measurable increases in reservoir capacity/streamflow. Despite localized very heavy totals, spatially-averaged totals are not that high, and the ground is so dry that not much will actually generate runoff. The main benefit here would be local/regional/temporary decreases in wildfire risk, though in other areas widespread lightning has more than negated the precip benefit.

      • Yes. Way more…Our Reservoirs here in the South Bay are nearly empty. This has really killed the freshwater fishing here. They can’t save the fish, so they end up dying.

    • rob b

      It has to help, I know Donner Lake has seen it’s level rise over the last week. That’s good news for residents of Reno, as the top 5ft of water is drained from Donner Lake after Labor Day weekend and sent towards Reno. I have been told that Reno “owns” that water but there is a deal in place they can’t drain the water before Labor Day Weekend.

      Hopefully we’ll see some rises in other area dams/water storage lakes like Boca and even Lake Tahoe. It seems these rounds of storms have really been focused on the Crest of the Sierra and even more the Eastern Side of Lake Tahoe/Truckee/Reno.

  • craig matthews

    12ZGFS shows a weak mid level low dropping south southeast down into the central coast tonight around the sub tropical low over Norcal. That is a strange idea and it would be the first time I have ever seen monsoon moisture enter the central coast area from the northwest. This is a very odd pattern.

    • Yeah. I don’t think I have ever seen this before…What an unusual Winter/Summer.

  • Joseph B.

    0.12″ in Martinez so far. Loving it!

  • craig matthews

    Those images Tweeted above on the right side of this blog on the Gulch Fire in Oregon look like a giant volcanic eruption. Has to be an extremely hot and intense fire to generate that kind of convection that high up in the atmosphere. Our local fire resources are stretched thin already and its a good thing that we are seeing wet thunderstorms across most of the state, though we are still getting some bad fires up north. Prayers go out to our boys on the fire line.

  • Cachagua1

    Great site. State reservoir levels are surpassing all time lows! I can’t imagine what another dry winter would do to California. I am tired of seeing my front view glittered with dead oak trees all over the mountains. I have been taking my grey water and tying it into a drip system that goes to the sycamore and alder trees on my property that are normally sitting in a full running stream year around. I use bio soap so to not hurt anything, not to brag here, but I think its a good idea. These trees seam to be taking to my grey water so far. But elsewhere along the creek out front, trees are almost all dead. Never seen anything like this. We have had bad droughts in the past, but I do not remember seeing creeks that run year around stay completely dry for 2 years.

    • Xerophobe

      I think the sycamore and alders can go dormant in times of great stress. You are doing good with the grey water, just be sure to water enough in that it gets down to root level. I’m no arborist but if you have deciduous trees I think you need to be less concerned about watering at the drip line of the tree, because the trees are bare when it rains, unlike live oaks and redwoods and evergreens. (but check it out) I know enough to be a lose cannon.

      • Cachagua1

        When sycamores and alders start to loose their cambium layer, or the bark starts to peel off and you can see straight into the heartwood, that usually means the tree is either dying or completely dead. Many sycamore and alder trees along my creek are doing this very thing and it is scary. So the few alders that are remaining barely alive, I am making every attempt to keep them alive even if they drop their leaves knowing that they are going dormant to sustain themselves until water comes. My drip system goes 3-5ft down underground and I have noticed some improvement of the few alders and the one sycamore I have left here. I hope it works because I would like to atleast have a few of these river trees left on my property.

        • Xerophobe

          I was talking with a couple just today who are out in the Village and they were mentioning the same things as you as well as some of their oaks. I don’t know if their oaks were diseased before the drought but it seems the same situation. I had no idea that was happening to the trees along the creek bed. Thanks for pointing that out. It’s hard for me to admit but this summer here on the coast has been most pleasant. Usually I count on one hand the ‘nice days’ each summer, yet this year, up until a couple of weeks ago I was counting fog/overcast days on one hand.

  • Kamau40

    Howard discusses the unusual weather pattern for Ca/NV. He also mentions a return to the S.E flow weather pattern shaping up as early as next Mon and is likely to continue off and on into at least the 3rd week of Aug. Based on how the weather has been since the beginning of summer, this could also mean more monsoonal moisture surges for Ca. There is another very important point he made within his blog today. The water temperatures off the Sea of Cortez and down within the Baja area, the water temperatures are running as high as 90 degrees which could very well setup the potential for a tropical system to eventually affect the So.Cal and the L.A. area and perhaps even statewide later this summer. In addition, the water temperatures off the coast of Ca. has been running way above avg. too. This may also be part of the reason why we have been experiencing monsoonal surges much further west than usual. This has been a very interesting summer indeed.
    http://mammothweather.com/

    • xeren

      sometimes howard’s posts are a little too techy for me, but I always try to read them. this one was much more readable for the layperson.

      very crazy about the storm potentially making a u turn and coming back to socal! i wish it wouldn’t run out of water before it made it back down here

      • Bandini

        Agreed he geeks out but I still love him. He really has central Sierra weather down.

        • xeren

          yep, and sure enough, that storm is rolling back down the coast right now! as predicted, isn’t producing too much rain though

  • David Thomas

    This will make things a little more fun come fall and winter if we get any good flooding rain events things do not look good for the dam right now good thing we are in the dry season still but if we get back two back flooding rain events or hvy rain wish would likey refill the lake up the dam could break if a fix don’t come soon

    http://www.uniondemocrat.com/News/Local-News/New-cracking-at-Twain-Harte-Lake-dam-worrisome

  • Kamau40

    Latest weather statement from this afternoon maintains the possibility of precipitation thru Wed, especially in the Nor. Bay. The low pressure system is expected to re-curve southward later tonight into Wed which the models indicated quite well. Currently, it is cloudy with some very light rainfall, but so far no convective activity. Interestingly though, the European models are suggesting another cut-off low pressure system affecting Nor. Cal. later in the weekend into early next week. It is something that bears watching as we have just entered into that time of year where we can experience see cutoff low pressure systems.

  • geopower

    Reno is already over 1.1 inches of precipitation so far this month. Five days in that makes this the wettest month here in a year and a half, since December 2012, when we had a whopping 2.1″ over 3 storms. The last time before that we had over an inch in a month was January 2012 at 1.5″. The ground here is loving the rain.

  • alanstorm

    FINALLY SOME REAL RAINDROPS!! It took forever, but now the west side of Mendocino Co highlands are getting wet. So dry, drops are making “puffs” in the dust. Don’t see any lightning, so all is well. Fire planes still flying constantly, so hopefully this is helping get those fires under control. What’s this about another cut-off low with a monsoonal connection next weekend??

    • Kamau40

      That is awesome, you guys finally got some REAL RAINDROPS. We had a few last night. Even though it was not a whole lot, it just felt good to see actual water to fall from the sky period. Today, it has been mostly cloudy and humid, no thunderstorms this time. At some point in time I believe we will get our share. Yes, the latest European models are already suggesting another cut-off low that may affect us with yet another monsoonal connection late next weekend. Even though it is still 5 days out, it is certainly a possibility with a SE flow developing late next weekend and early next week. Something I think is definitely worth watching in the coming days!!

  • geopower

    I’ve seen pyrocumulus clouds before, but never from their level. Stunning pics of the start of the Oregon Gulch fire: http://www.slate.com/blogs/future_tense/2014/08/05/oregon_gulch_fire_photos_show_pyrocumulus_clouds_and_fighter_jets_over_wildfire.html

    • Dan the Weatherman

      Those were some really neat close-up shots of the clouds. They look HUGE from that perspective!

  • Bandini

    Tahoe Basin and Truckee have felt and look like the Pacific Northwest for the past 48 hours. I sure hope these are early signs of a huge winter, either way it is great right now.

  • lightning10

    Is it Christmas yet? Am I watching the Chargers take the AFC West while eating my Christmas cookies? It will be December with I hope 20 inches of rain!

    • Xerophobe

      Oh that is soooo funny.

    • so.cal.storm.lover

      Same here lol. I love the chargers.

  • Xerophobe

    Here’s NOAA’s NWS glossary for terms, phrases and abbreviations.
    for understanding Wx geek talk from the pros and posers (with no t) like me.

    http://w1.weather.gov/glossary/

    and I have found Unisys page helpful too.

    http://weather.unisys.com/upper_air/details.php

    Oh and BTW some rain drops in South Santa Clara County and here is another TPW anomaly forecast for 24 hours.

  • 60blue

    I have been looking at earth.nullschool.net for the past few weeks. There seems to be a lot of activity in the Pacific now. Is this unusual? Is it a predictor of whether or not we will see an El Niño?
    This is a great website and I am learning a lot!

    • Xerophobe

      It’s unusual for Hawaii to possibly get hit by two hurricanes in a year let alone this weekend. Although Julio may travel just north of the Islands on Sunday. Iselle seems forecast to hit the Big Island like a bullseye on Friday morning.

    • Some of the increased oceanic heat from the big Kelvin wave earlier this year has dispersed N and S of the equator, which may be contributing to increasing tropical cyclone activity. To the extent that the Kelvin wave was related to the still-developing El Nino, there is probably some relationship, though it would be indirect.

  • Dogwood

    A few drops fell downtown San Jose at dawn I noticed.
    August is a tough one- would be very rare for my location to get real rain: 1997 (.51), ’76 (.71), ’75 (.68) & ’68 (1.98), the only notable accumulations in my lifetime.
    Add a couple of hundredths on a scant few occasions.
    Enjoy it where you’re getting it!

    • I had an opportunity to drive from Downtown SJ to Campbell and back around 6 AM. I felt it to be a good dousing, say somewhere between 0.001 to 0.01. Among other things, I was greeted by my very wet indoor-outdoor cat when I got back.

    • C M

      Were any of those events thunderstorms? What was the temperature during those rain events?

  • Reeks_

    So is this weird overcast, muggy, hot, weather normal for Northern Bay Area?

    • tomocean

      No. Monsoon events can certainly occur anywhere in California in the Summer, but the strength and frequency this year is very unusual.

      • Reeks_

        So is the monsoon weather and dewpoints causing the weird summer weather. I like in the bay area (Napa Valley and the sky is hazy blue and then looks completely overcast where the hills touch the sky

    • xeren

      it’s not really normal for most places in california. the last time i felt humidity in los angeles was probably 2 or 3 years ago?

    • Definitely not. Dewpoints today were as high as the upper 60s–phenomenally high for the Bay Area, and probably record-breaking (if such records were regularly reported, which I suspect they are not).

      • Boiio

        Had a high dew point of 66 today. Can’t ever remember seeing readings that high around here. Feels like Hawaii!

      • Reeks_

        What do the dewpoints effect?

  • redlands

    pics

  • so.cal.storm.lover

    Wouldn’t the best chance of a hurricane/tropical storm hitting california would be in late september/october when there is a low off coast pushing the hurricanes that come north in cal. Also the warm ssts off the whole coast off mexico and california.

    • Typically, yes–that would be the likeliest time of year. But with SSTs quite high presently, and a trend toward anomalous low pressure regions near CA this summer, it’s possible at any point for the rest of summer, too. But keep in mind that it would still be quite unlikely for an actual hurricane/TS to hit CA directly. Not impossible, but very unlikely. Remnants from such storms, however–including tropical moisture and even a closed circulation–can result in significant weather events here every 3-7 years or so.

      • so.cal.storm.lover

        Has that event happened in the last 3-7 years, otherwise saying are we due for a significant weather event.

        • Dogwood

          In early October 2009 the remnants of Japanese Typhoon Melor got hooked up with an offshore low and just walloped the state. 21″ of rain above Big Sur. Several feet of Sierra snow.
          And the astute meteorologists called that one a week in advance.

          • Dan the Weatherman

            Even the remnants of Melor brought some good early season rain to Socal. I believe I picked up just under a half inch from that storm here in Orange.

        • xeren

          we can be “due” for an earthquake because of pressure building up in the earth, and we can be “due” for an el nino event because of the natural oscillation back and forth of SST anomalies

          but i feel like individual weather events are too random (or at least we still don’t know enough about them) to say we are due for a so cal tropical storm remnant, other than to say that we know how often they happen on average, and that it has been X years past the average. nothing is really building up to force an individual event to occur

        • xeren

          check out my awesome excel skills! i made a chart of the occurrences of what wikipedia considers california hurricanes, from here: http://en.wikipedia.org/wiki/List_of_California_hurricanes

          http://i.imgur.com/AE0zsQp.png

          as you can see, there isn’t much predictability to it. the years where multiple events happened in one season tended to end up being el nino years, but there are tons of el nino years that has zero hurricanes, so there isn’t a whole lot to say other than “hurricanes like warm water”, but we already knew that- they don’t really become overdue as far as i can tell.

          • To be clear, in none of these years did an actual hurricane make landfall in California. These would mostly be years when remnant moisture/circulations made it ashore, and in a couple of instances when a weakening tropical storm/depression approached the coast.

          • C M

            Actually- a hurricane has made landfall in San Diego before; http://en.wikipedia.org/wiki/1858_San_Diego_hurricane
            If it happened once, I think it could happen again. Don’t wish for this to happen as it would cause widespread devastation and some deaths since Southern California’s landscape and architecture is NOT build to withstand such heavy rain and winds.

          • In 1858, a tropical cyclone (perhaps a hurricane) did indeed make a close approach to San Diego (though did not actually make landfall). However, it remains the case that no hurricane in the 20th or 21st century has made landfall in California. It’s very unlikely, but not impossible, and it were to occur it would most likely be during a strong El Nino year with elevated E Pac SSTs.

          • so.cal.storm.lover

            Yes climate change may be a factor in those numbers going up.

        • That’s just an average recurrence interval–there’s no physical reason to expect that a event is more likely now simply because it hasn’t occurred recently. However, there are some physical reasons to believe that the likelihood may be higher than usual this summer, but they have nothing to do with the time elapsed from the last event.

          • C M

            Flip a coin and get 6 heads in a row. Next flip does NOT mean a higher chance of tails; it’s still 50/50. I believe the same principal applies in weather. A 100 year event could occur 2 years in a row or there could 500 years before it repeats itself.

          • Ross Mccorkle

            It’s been a LONG time since we’ve had any tropical moisture from a tropical stormhurricane coming up Baja. I recall a few such events in the earlymid 90’s and honestly can’t remember one happening since.

  • redlands

    A picture just recently

  • rob b

    Looks like rain and some thunderstorms developing around I80 over the Sierra Crest. A week of rain everyday would sure be nice.

  • Bandini

    Thunder and lightning at Donner around 3-4 pm with rain, looks like the Emigrant Gap area has some heavy cells coming in.

    • geopower

      A line of thunderheads building over Reno right now:

      • Bandini

        Nice! I took this on my way home 20 minutes ago, heading south across Martis Valley on 267 towards Kings Beach. Carson range, literally directly on the other side of those clouds. Hope you get some action.

        • geopower

          Sadly that line sputtered and dissipated. it’s hard to be too disappointed though, after the great week we’ve been having here.

  • C M

    San Jose actually had some warm rain this morning. Temperatures were in the low 70s around 7AM (normally it’s around 55-65 that early in the morning even on days that exceed 90 in the afternoon). The afternoon was humid and in the mid 80s- I felt like I was on the East Coast. The only thing missing was thunder and lightning.

  • Ian Alan

    Monsoon moisture back on tap for next week according to NWS SD with a closed low – again – low confidence – again. Flip flopping I’m sure will continue until rain drops fall from the sky, or not. LOL

    Summer rain forecastng is maddening.

  • David Thomas

    With all the hurricane going on in the C PAC and W PAC. Oct. Could be vary wet in CA in other words we could be looking at a vary. Early start two the rainy season. May be has early has mid two late Sepmber.

    Oct is looking vary wet

    The 1st GFS map is 204hrs out show a nic fall storm but weakens buy time it gets here in the long ranges GFS the W PAC. Stays vary stormy has you will see

    The long rages even has a stronger storm

    It’s only a matter of time. But am likening what am seeing. I would keep a eye. On the GFS runs the cold fronts are looking vary good for this time of year any comment on this post ?

    • geopower

      Try typing your comments in Word first to use the spell/grammar check, then paste? It’s pretty hard to follow your comment as written.

      I’m not aware that tropical hurricanes headed west from the C PAC have any impact on rains in California. Especially August hurricanes on October rains. But maybe I misunderstood what you were getting at.

      • In the fall months, California can occasionally see some pretty dramatic downstream effects of W. Pac. typhoons if enough energy is entrained into the Westerlies. Happened pretty dramatically with Supertyphoon Melor a few years ago, when NorCal saw a very unusual extreme rain/wind event in October.

        • geopower

          Well then, fingers crossed for October hurricanes with northerly tracks I guess.

  • Bob G
    • Xerophobe

      I was going to type a diatribe about this article but like most of the time, I don’t post them.
      Don’t get depressed unless you were in the super El Nino camp.
      Rain is what we need this winter.

    • Things certainly don’t look as promising for a strong/very strong event as they did 3-4 months ago, but calls for “El Nino’s demise” remain premature. The Pacific has been behaving strangely lately, and there is some evidence of a transition between large-scale states (ENSO and/or PDO-related), so as frustrating as it is I think we’ll still just need to wait and see.

      • Kamau40

        According to the latest CFS models though, it still is projecting at least a moderate ENSO event.

      • Kamau40

        Dan-
        Remember though as I have said many times on previous blogs and shown with great supportive facts of past years as good detailed examples, we don’t necessarily have to have an El Niño to develop to have a wet winter in Ca. I have lived in both So. Cal and Nor. Cal all of my life and have seen wet winters in non El Niño years. Although as you know the system does increase the odds of having a wet winter, but even that is not guaranteed. There have been some strong events in the past that has produced just avg. or even below precipitation statewide. What really matters along with of course other global tele-connections and oscillations is having the jet stream in the right position to give the state a great wet season. Moreover, the system does not just affect Ca. weather, but it affects the weather on a global scale as a whole. The forecast, however, does help to make planning easier due to the advancement in technology.

    • Bob G

      I sure hope the rain comes. Another dry year is going to be a disaster in so many ways. Being involved in agriculture, some farmers were really hurt while many are managing to get by this year. Another dry year and I suspect there will be no surface water available for anyone. I also believe that residential users will really feel the impact of another dry year, much more than they have this year.

    • Bartshe

      Thanks for flagging the article.

      Bill Patzert is making more bearish projections on the winter. Seems like California news media does not put forth a climate-related article without getting his commentary.

      Sobering and salient comment by Jay Lund at the end of the article.

      • Bob G

        The state is behind in creating water storage and has been kicking the can down the road for years. Friant Dam, which feeds the San Joaquin River, was at approx 40% full and did not release any water this year except for some water to satisfy exchange contractors. If we have another dry year, I would expect to see no releases from Shasta Dam either except for urban use and that would be based on strict rationing.

  • A very active summer weather pattern appears likely to continue over the next 10 days after a brief lull at present. In fact, Central/Northern coastal areas may see their best shot at thunderstorms yet this summer somewhere in the day 5-8 period. I’ll have a full update this weekend summarizing recent events and the medium-term forecast.

    • Bob G

      Where I am from in Central CA, we haven’t seen a drop in moisture from all of this summer moisture. That can be good or bad depending on who you are. It would be really nice to get a good soaker in late September or early October. A few years ago I recall getting three inches of rain from a storm that hit us late September/early October

      • Yes–the “have nots” in this drought continue to mostly miss out on what modest precipitation has fallen this summer. Unfortunately, the upcoming event will probably not be as moist as the previous one (even if dynamics are better), so while the risk of lightning may increase the risk of heavy downpours may actually decrease. Stay tuned.

    • Kamau40

      Yep, I have in recent days starting to see model trends pointing to that likely hood of thunderstorm activity.

    • C M

      I’d love to see a good thunderstorm here in San Jose but don’t want to any fires started by lightning strikes. Are we talking cloud-to-cloud lightning or cloud-to-ground lightning?

  • Xerophobe

    What is promising to me at least is the latest CFSv2 forecast seasonal normalized precip. anomalies with skill mask is FINALLY showing a leaning towards more than a 50/50 +rain forecast for the first time that I have seen. I’m not sure I understand what I just typed nor can I define this map, however this is the most conservative (conservative probably isn’t the right term either) outlook that I know on the CPC website.

  • Kamau40

    Here is an excellent explanation from NOAA’s statement today regarding what is current happening with the development of El Nino and why the models are still predicting a weak to moderate event by Fall/early Winter.
    http://www.climate.gov/news-features/blogs/enso/details-august-7th-enso-discussion-how-has-forecast-changed

    • Xerophobe

      Here’s your warm water. Latest JPL image. And in the far Western Pacific the SST’s seem to be looking cooler, which is what they should be doing for +ENSO

  • so.cal.storm.lover

    You guys should check out southern california weather central they have extremely accurate weather and hit the things nws don’t. The gentleman who runs the page has a facebook you should like it keeps you updated with all of the accurate forecast and he also has an email alert system.
    http://www.southerncaliforniaweathercentral.com/

    • C M

      Kevin Martin is NOT a certified meteorologist; take what he says with a grain of salt.

      • so.cal.storm.lover

        They say that because they fear him people are jealous ive been seeing him forecast spot on for the past year, if you like his page he is very accurate he got the whole july 2014 forecast right for so cal and he get the things that nws misses (which is a lot of things). He’s trying to get the site big by winter to save lives and make money for his friend (that helps with the site) for a bucket list his friend who has stage four skin cancer and only has 2 years left. He admitted on his site he doesn’t have degree or phd but is extremely accurate you shoult take some time to check him out

    • xeren

      kevin martin is a scam artist, according to rational wiki. the NWS has also put out a press release talking about his false “official” reports

      http://rationalwiki.org/wiki/Kevin_Martin

      http://www.nws.noaa.gov/om/notification/pns11martin.txt

      http://kevinmartinscwxa.blogspot.com/

      look at the rest of the kevin martin nws search results:

      https://www.google.com/search?q=kevin+martin&oq=kevin+martin#q=kevin+martin+nws

      take his weather reports, and anything he says, for that matter with a giant boulder of salt

      • Mike Stephenson

        Ive followed him for a while but take it for what it is, Ive seen him make some very accurate and informative casts for Socal. I really enjoyed his private weather site scwxa. He would occasionally forecast dangers that NWS missed. (Dont mean to bag on NWS)

        • xeren

          I followed him for a while as well, and found his forecasts to be less accurate, and usually filled with hyberbole. “The storm will SMASH into socal!” For storms forecasted to get .10″ and we end up getting .05″. There are several other socal forecasters I prefer, including Howard sheckter, who just mentions so cal offhand but has been more accurate than km.

          But ignoring that, I can’t support such a mean hearted person, who will go to any lengths to smear those who disagree with him. If you believe what the people wrote in the links I provided, he is a fundamentally bad human being

          • Mike Stephenson

            I guess i can’t disagree, I just thought his site was cool to help you understand whats going on a little better and his casts were fun. Is what it is i guess

      • so.cal.storm.lover

        They say that because they fear him people are jealous ive been seeing him forecast spot on for the past year, if you like his page he is very accurate he got the whole july 2014 forecast right for so cal and he get the things that nws misses (which is a lot of things). He’s trying to get the site big by winter to save lives and make money for his friend (that helps with the site) for a bucket list his friend who has stage four skin cancer and only has 2 years left. He admitted on his site he doesn’t have degree or phd but is extremely accurate you shoult take some time to check him out.

        • xeren

          Oh jeez, I give up. I just hope other people read those links I provided, even if you dont

          • so.cal.storm.lover

            There are trolls attacking his site and facebook that he has be spending hundreds of dollars on.

          • xeren

            you say trolls, i say people getting fed up with his scams

          • xeren

            “The new website he will be running with his (multiple personalities) imaginary editors and co-workers is called public weather service. (publicweatherservice. com) I strongly advise you against visiting that site as people have allegedly been attacked with trojans and viruses on his previous websites. This move is just the next in line from from the many previous websites which included but is not limited to cashgiftingtwins, ows, ontarioweatherservice, southerncaliforniaweatherauthority, SCWXA, theweatherspace, haarpstatus, chemtrailstatus, chemtrailforecasts, and many more, it is hard to keep up with a person with such a vivid imagination.

            Please put the word out because friends don’t let friends listen to bogus weather reports from a person who’s only claim to knowledge about weather comes from a lightning strike and or being autistic, it depends on the mood he is in to which it is.”

            http://kevinmartinscwxa.blogspot.com/

  • Kamau40

    The week of Aug 17-23 bears watching!! We could see some very interesting weather event here on the west coast. Yes, it has a lot to due with the highly amplified “dipole” weather pattern which will bring well below normal temperatures in the Mid-West and East Coast. Also, there is yet another typhoon in the Pacific that will first impact Japan and then could curve and move into the westerlies, which mean more heat or above avg. temp in the West and the possibility of another significant monsoonal surge for Ca.

  • Bandini

    Some heavy cells moving into west shore and now firing up into Truckee, red on the radar in spots. Lots of thunder.

    • Kamau40

      Nice!! You guys are just not getting a break from thunderstorms this summer. They just keep on coming. Now, I’m just waiting for them to head this way to the Nor.Cal. coastal sections.

  • Bandini

    Looking west.

  • Sunchaser
    • Oh great……

    • Dan the Weatherman

      The article states: “The strongest El Niño events in California occurred in 1983 to 1984 and 1993 to 1994”.

      Wrong! They occurred in 1982-83 and 1997-98. Somebody needs to do their research!

      • Sunchaser

        That’s the LA times for ya….lol

  • Bandini

    Took this from my place (6300ft) around 5:00 this evening as I saw a line of heavy cells firing up along the crest and heading east. Big red and yellow cells with constant thunder and lightning but at my place just some big drops but no downpours. It is unreal how much activity we’ve been getting lately. It seems that everyday there is a storm lately. I know hardly anything, which is why I enjoy reading this blog, but it sure seems like all this action must be a sign of something right…? Like a massive winter to come. Probably wishful thinking but I’ll tell you this is a blast.

    • craig matthews

      I love your pictures. They make up for the boring marine layer I see every day I look out my window. Those are some intense cumulus clouds, lots of instability up there, and looks like some smoke in the air too. Wish I was up there to experience these storms.

      • Bandini

        Thanks! Yeah it has been fun lately. I can see them forming again today but it looks like they might be staying to the south and east. Hoping for action from tomorrow through Tuesday.

  • Kamau40

    Mammoth was a very wet month. They picked up 1.45in of rainfall for the month of July and so far in Aug they have already picked over .50in of rain. All of this activity the mountains have been experiencing is indeed very unusual and could be a good sign of things to come in the future!!

    • Azmordean

      This is excellent news! Certainly not drought busting rains, but 2in of rain has to make a huge difference for local trees and wildlife, as well as dammpen fire danger a bit.

      That said, my inclination is that unfortunately it tells us little about this winter, since the summer monsoon is a totally different pattern than what we would see in winter. My hope is for a wet winter, but at this point, with El Nino looking weak-moderate, I think our chances are 50-50 and the strong monsoon doesn’t really change that.

      • Yeah, the summer monsoon pattern is not really a predictor for the following winter. Recent thunderstorms have certainly brought some highly localized benefits, but they remain relatively insignificant in the long run and in the broad scheme of things, unfortunately.

        • Bartshe

          living just north of Mammoth I can attest to the fact that the rain in the Sierra is highly localized in terrain-favored areas and overall there has been little to no rain over the broader region

      • Kamau40

        Ditto Dan’s comments below. Furthermore, a good start to the rainy season does not necessarily mean a great winter ahead. I have seen many good starts and bad finishes over the years. In reality, no one really knows what the upcoming winter will look like. We will just have to wait and see and pray that we do not end up with another bone dry year.

  • Kamau40

    Midday Sun-Mon bears watching for possible isolated thunderstorms for Nor.Cal incl. the S.F. Bay Area. The extended forecast for later next week is also uncertain:
    The Area forecast discussion
    National Weather Service San Francisco Bay area
    858 PM PDT Thursday Aug 7 2014

    Synopsis…slightly cooler than normal temperatures are expected
    through the weekend and into early next week as weak low pressure
    develops off the California coast. Somewhat warmer weather is
    forecast during the second half of next week.

    &&

    Discussion…as of 8:55 PM PDT Thursday…temperatures were
    slightly below normal today due to a relatively deep marine
    layer and moderate onshore flow.

    Water vapor satellite imagery currently shows a series of weak
    upper level disturbances over the eastern Pacific along 40n. The
    first of these disturbances should help maintain a relatively deep
    marine layer as it approaches the northern California coast
    tonight. One of these disturbances is forecast to move to the east-southeast
    and form a cutoff low west of San Francisco by Saturday afternoon.
    On that point the models agree quite well. Formation of this
    cutoff low will likely result in further deepening of the marine
    layer over the weekend. As the low draws closer to the coast later
    in the weekend…we may even see the marine layer mix out entirely.
    Temperatures are expected to remain on the cool side of normal
    right on through the weekend and into early next week due to this
    upper low.

    As the low approaches the coast this weekend it should tap into
    some monsoonal moisture to our east and southeast. Most of that
    middle/upper level moisture is expected to wrap around the north side
    of the upper low and remain to our north and east. However…the
    18z GFS forecasts isolated quantitative precipitation forecast across our area from midday Sunday
    through midday Monday. The latest NAM and European model (ecmwf) keep our area
    entirely dry (except perhaps for some coastal drizzle falling out
    of the marine layer clouds). The 18z NAM indicated an increase in
    middle level moisture over the weekend…but the 00z NAM shows less
    moisture reaching our area. However…the 00z NAM does forecast
    increasing instability over our area as the weekend wears on. In
    fact…the 00z NAM shows MUCAPE values in excess of 300 j/kg
    across the sf Bay area on Sunday. If that much instability were to
    phase with sufficient middle level moisture we could see isolated
    thunderstorms late in the weekend and into Monday. There is still
    too much model inconsistency and disagreement to add thunderstorms
    to the forecast at this point. But future forecast updates may
    need include a slight chance of thunderstorms for later in the
    weekend…depending on what the next few model runs show.

    The upper low is forecast to move to the east of our area by
    Tuesday of next week…which should allow temperatures to warm back to
    normal during the second half of the week. However…the medium
    range models disagree on how the pattern will evolve late in the
    extended. The 18z GFS and 12z GFS ensemble mean show an upper
    ridge developing just off the West Coast by Thursday while the
    12z European model (ecmwf) develops another cutoff low offshore.

    • craig matthews

      Seams like the last few thunderstorm events have gone completely around coastal Monterey county. I hope that cut off low develops more to my southwest so moisture/instability can be pulled back to the west northwest further south over my domain, so I can see some action where I live too. Seams like its consistently been a Bay area north situation lately with the low centers being too far north from where I live. Hopefully it will be different this time around. But I might need to take a trip up north if this keeps up.

    • rob b

      I/We have had some interesting discussions on Twitter this AM with meteorologists at a local TV Station and NWS offices in regards late Sunday/Monday on the chance of thunderstorms and hopefully rain. Some of the models show a lot of moisture focused towards the Sierra over the Lake Tahoe area, also see some north of the Bay Area. From their trained eyes could be interesting, hopefully these storms carry moisture and are not just dry lightning.

  • alanstorm

    Yesterday’s Contra Costa Times ruined my day with its “El Nino is Fizzling Out” bullcrap. How dare they make such a gloom & doom proclaimation?. Wasn’t long ago it was proclaimed a “Super El Nino” was developing, so obviously it could easily rebuild as fast as it fizzled.They went on to predict “another dry winter” & no mention of the RRR’s role in the drought. We can have a wet winter WITHOUT. El Nino, ya know. HELLO??.

    • Right. The key message–which continues to be underemphasized–is that El Nino is only a meaningful predictor for our area if it’s quite strong. Wet winters certainly occur here without El Nino. However, the absence of a strong El Nino does somewhat diminish the likelihood of the very wet kind of winter we’d need to see to make major progress in erasing long-term precip deficits. That does NOT mean we will see another dry year (though it also not not mean that we won’t). In a month or two we may have a better idea what the upcoming winter will look like regardless of ENSO based on the SST configuration. Currently things still look vaguely PDO+, which would at least signal a change from last winter’s extreme conditions (though the persistence of the North American Dipole pattern this summer is a bit unnerving).

      • Dan the Weatherman

        Even if we only have a weak El Nino, is there a better chance of the subtropical and/or southern branch of the polar jet potentially undercutting the persistent ridging in the North Pacific with the current SST configuration with a more positive PDO?

        • craig matthews

          Hi Dan T. W. M. I think you’re right. Positive PDO and even a weakly positive ENSO increase the odds of California having a wetter then average winter, especially socal, as both ENSO and the PDO are “in phase” with each other, in a positive mode, and those forcings involved lend the westerlies moving across the north pacific basin an extra hand in getting further east toward the west coast. I haven’t heard the latest PDO index for July, but it must still be positive, because it appears SSTA configuration has not changed much in the North pacific basin around 20N. Have you heard any updates on the PDO?

          • Kamau40

            Craig-
            I have been keeping track of the PDO on a monthly basis, the July values have not came out yet. It should come out sometime in the next week. But, looking at the overall ssta in Nor. Pacific, everything is still in the positive territory.

          • Dan the Weatherman

            I haven’t heard any updates, but CPC’s latest ENSO Diagnostics Discussion SST anomaly map of the north Pacific still shows a +PDO signature. The only bad thing I have seen on their maps is that the central and eastern equatorial Pacific has cooled down in the last 4 weeks, but the western Pacific has been trending cooler during the same time period, which could be a good sign.

          • Kamau40

            Dan-
            Earlier today I was looking at the SST maps and the Pacific Ocean is still in the +PDO mode overall which is a good thing. The Western Pacific has indeed been cooling which to me could be a good sign.

      • craig matthews

        I have heard the very active typhoon activity in the western tropical pacific might be a partial reason for the persistence of the North American Dipole pattern this summer. There was an article about this last month and I was wondering about it.

    • Let’s see if we have an El Nino how the RRR will play out. I will be beyond baffled if it is still blocking storms our way. We could be heading into a major disaster here soon.

  • lightning10

    I have seen for So Cal during the months of July, August, September, and November when So Cal gets above average rain in any of the months it often means less rain in the Winter.

    While October is the only month that if we get above average rain it has always lead up to an above average Winter.

    • C M

      The few Julys and Augusts that San Jose saw measurable rainfall usually resulted in above average rain the following winter. August 1968, a thunderstorm dropped almost 2 inches of rain in one day and that turned out to be one of the wettest winters on record.

    • Dan the Weatherman

      Recent years have certainly been drier than normal when we have had measurable rain during the summer months, but it hasn’t always been the case in the past. A good example of this recent phenomenon is 2006-07, but examples of the past include 1939 and 1997.

  • Now appears there will be a major NorCal lightning outbreak Sunday-Monday. Blog update most likely Saturday, definitely by Sunday noon.

    • C M

      Any chance of audible thunder and visible bolts in San Jose or is just a mountain event?

    • Bandini

      I was just reading that, looks like the Northern Sierra could be getting blasted, hopefully accompanied by rain.

  • craig matthews

    18zGFS for Sunday morning/ at the 500mb level. You couldn’t ask for a better set up for a thunderstorm outbreak over Norcal in the next couple a days. Recent models are now hanging this low off Bay area for up to 4 days. Time for me to travel north so I can see some action.

    • Kamau40

      Yes indeed!! It is the best setup for a nice thunderstorm outbreak for Nor. Cal. I hope you can make it up here during the Sun/Mon time frame because this where most of the action will be this time.

      • alanstorm

        Yes, come and watch everything burn. If this happens, look for a major fire catastrophe for everyone. It could burn for months.This is the worst thing that could happen right now.

        • Kamau40

          Hopefully the storms will have some moisture and not just dry lightning. Otherwise, if it is just dry lightning that would be very bad news especially with the exceptionally dry conditions with the ongoing extreme drought.

          • alanstorm

            That was my fear back in Jan when the RRR/wavey jet-stream was doing it’s thing. Hopefully not a repeat of summer ’08 when dry lighting started 100+ fires up here . Way drier now

    • This sucks. I am leaving to Southern California on Sunday. I will be back on Wednesday. Hopefully it sticks around by then.

      • craig matthews

        Yup, with this low were a bit more south. This projection would mean a dry southwest flow and thick and boring marine layer where I live.