2017 hottest summer in California history; Cut-off low may bring widespread thunderstorms

Filed in Uncategorized by on September 9, 2017 4,167 Comments

Overview of recent all-time record California heat

2017 was the warmest (or near-warmest) summer on record over most of the Western U.S. (NOAA/NCDC)

2017 brought extraordinary summer heat to California. While record-breaking early-season heatwaves largely spared the immediate coastal areas (but brought endless weeks of searing triple-digit heat to interior areas), extreme temperatures extended all the way to the beaches over the past couple of weeks.

The late summer and early autumn months are traditionally warmest of the year in coastal California, as the marine layer tends to become suppressed and offshore winds occasionally allow hotter air to encroach from the east. But the late August and early September heatwave that California just endured was on an entirely different level than those historically experienced–breaking (and, in many cases, shattering) temperature records of all kinds. Countless daily (and monthly) temperature records were set statewide, and this heatwave continued the already record-breaking streak of 100+ degree days across much of the Central Valley. Overnight temperatures stayed well above average daytime highs in many places, and new all-time “warmest minimum” records were set. Quite a few coastal or near-coastal California cities matched or exceeded their all-time temperature records for any month–an impressive list that spans from the North Coast (Eureka) to the central coast (San Luis Obispo) and apparently even includes (amazingly) the Farallon Islands in the midst of California’s cold oceanic upwelling zone. Easily the most amazing statistic during this extraordinary event was the fall of downtown San Francisco’s all-time temperature record, where the observed 106 degrees surged past the previous hottest temperature (103) in 147 years of record keeping.

It might not be a surprise, therefore, that summer 2017 was officially California’s hottest on record (and much of the Labor Day heatwave actually fell out outside of the formal June-August definition of “summer”). In fact, 2017 broke (by a considerable margin) the previous record set…just last year, in 2016. Indeed, this year once again puts an exclamation point on a sustained, long-term warming trend over the past century in California. Increasing frequency and intensity of extreme heatwaves is one of the clearest hallmarks of our warming climate, and it’s likely that “extreme” temperatures like those experienced this summer will become fairly routine in just a few decades.

California has experienced a sustained long-term warming trend in summer, and 2017 was the warmest season on record. (NOAA/NCDC)

 

Unusually widespread thunderstorm outbreak possible across California

An offshore cut-off low will be in a favorable position to produce relatively widespread thunderstorm activity. (NCEP via tropicaltidbits.com)

A slow-moving cut-off low pressure system is currently setting up shop off the Southern California coast, and has the potential to bring some very active weather to certain parts of the state over the next 5 days. Mountain and desert thunderstorms have already been quite active over the past few days, but beginning on Sunday convective development is likely much closer to (and perhaps including) the coast. In fact, convective parameters for late tomorrow afternoon for much of Southern California and the Central Coast are quite impressive, with able mid-level instability, sufficient column water vapor, and even some large-scale ascent forced by diffluent flow east of the offshore low.

With all of these ingredients in place, numerous thunderstorms will likely develop over the mountains of Southern California tomorrow afternoon, at least a handful of which will sustain themselves as they move east to west over the coastal plain and even offshore. At least a few of these storms may be quite strong (or even severe), bringing intense downpours along with possible hail and gusty winds. This, tomorrow could be a pretty active weather day even in places that rarely see this kind of vigorous thunderstorm activity.

An offshore jet streak will provide dynamical support for thunderstorms over the SoCal Bight on Sunday. (NCEP via tropicaltidbits.com)

There is at least a modest risk of flash flooding in interior areas hit by strong storms, and some localized issues could even occur outside of the mountains. It’s actually possible that thunderstorms may be more widespread tomorrow across portions of SoCal (including Los Angeles County) than they were during the recent “Lidia” tropical remnant event. (On a related note, if you haven’t checked out this video showing extraordinary webcam footage of the highly localized but quite damaging Santa Barbara microburst last week, you really should. Also, this one.).

On Monday and Tuesday, the thunderstorm threat will shift northward to encompass most of the rest of California–even including the Bay Area and Central Valley.

The GFS is showing fairly widespread precipitation accumulations over most of California over the next 5 days. (NCEP via tropicaltidbits.com)

Scattered thunderstorms may ultimately occur uniformly over much of NorCal as moisture and instability will be present virtually everywhere. This sort of synoptic set-up–with a fairly deep offshore cut-off low and modest amounts of late monsoonal moisture–is reminiscent of the sort of pattern that has historically caused spectacular early autumn lightning displays over parts of California. Hopefully, this event will be associated with enough wetting rainfall to avoid numerous wildfire strikes, but given the time of year and the antecedent heat/dryness, this event will probably pose a significant fire weather threat.

Later next week, the cut-off low will finally move inland and perhaps bring a final round of isolated showers and thunderstorms to a fairly broad area (perhaps even the coast), though coverage and intensity should be less than earlier in the week. After that, quieter weather conditions will likely return.

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  • HD

    Longtime lurker, haven’t posted in a long time here. But always read up the knowledgeable comment section. Got this shot today, single bolt! Probably from the cell which disrupted SFO airport.
    https://www.instagram.com/p/BY7lOXhBizP/

    • alanstorm

      You just blew my mind!
      That’s amazing

      • HD

        Thank you!! Always love reading your posts!

    • Sokafriend

      Spectacular!! Thanks for keeping us in mind. I would never have imagined this over SF.

      • HD

        Yeah! This is by far the best storm I have ever photographed. It was tough with radar down but had a lot of fun chasing the cells.

        • Sokafriend

          It’s great that you got out to do that- it sure seems to have been a rather historic event and your precise capture is stunning.

    • Cap’n

      Great work that is fantastic.

      • HD

        Thank you!

    • alanstorm

      You mentioned SFO getting hit- scroll down to the video of the 10+ CG strikes coming in rapid succession right around Millbrae. Whoah!
      Looks downright DANGEROUS
      http://sfist.com/2017/09/11/photos_freak_september_thunderstorm.php

    • EdInRanchoBernardo

      Great photo!! And with this being a single bolt (split into 3), I betcha the thunder was quite a bit louder compared to just one cloud to ground strike.

      • HD

        Thank you! It was really really loud indeed.

    • Fantastic!

    • Dan the Weatherman

      That’s quite a lightning flash!

    • CHeden

      10 thumbs up!! Truly magnificent display.
      BTW, was this is a still or a video capture? Just curious.
      Either way, a real treasure for the archives.

      • HD

        It is a still. I have a lot more. I will post them in the evening. This storm was definitely the best one I have ever witnessed.

    • osc3_el cerrito

      Wow! Great shot.

    • Thirstier Nick (Santa Maria)

      Worth more than a thousand words.

  • Who Killed Kenny Strawn?

    Why is the Bay Area stealing our thunder? It’s usually Southern California that gets those rare summer storms and the Bay Area gets the bigger brunt of the winter storms?

    • I’m not trippin.

    • rob b-Truckee/East Bay

      Funny you say that Steve Paulson discussed this this AM on KTVU-The Bay Area normally sees Thunderstorms around May and Sept as the seasons are changing.

  • sezwhom

    Well, hello EURO. First rain of the season from the north? Magical 564 goes right through the Bay Area. Probably windy and cooler since main trajectory is more over land but it might be close!https://uploads.disquscdn.com/images/2c3a0c0416b71d4045fb1d48f61ae466a5f01f41c56b3c9e2b312a2e65bff722.png

    • Hopefully it pans out! I’m over heatwaves and summer.

    • Thunder98 (Santa Maria Valley)

      A 2010-2011 or a 2016-2017 winter redux please!

    • Nathan

      can you explain what you mean by “maigcal 564”? Is that the dm line that usually results in rainfall?

      • FolsomPrisonBlues

        I believe it means that the pressure level is 546 mb, or around 5500 meters above sea level. Not sure if that is totally accurate or not. And I am not sure what that means exactly regarding the weather.

        This has some good info though. I am reading it now:
        http://www.theweatherprediction.com/habyhints/97/

  • Taz & Storm Master

    Major pattern changes coming it seem starting this week and lasting too mid too late September on beyond maybe it looks like summer will be coming too a end and getting in to some really cool fall like weather it may even feel chilly Overnight

    • RunningSprings6250

      Maybe time for the new name? With a potential season change ‘n all?

      • Taz & Storm Master

        I keep storm master for good luck

    • MetaGhost (Berkeley)

      Isn’t Sept. 12 mid-Sept?

  • Rainmaker (San Jose)

    i’m making the call, no more 90’s for San Jose this year

    • Chris

      No complaints there and I hope you are right!!!

      • Pfirman

        That fool is tempting the weather gods.

  • shampeon

    Caught this #Lightning #bolt in SLO-Mo on the iPhone . #San Francisco #Lightning and #Thunder !! Crazy weather in the city! pic.twitter.com/yakaH5kdoj— Arturo Trujillo (@Turo420) September 12, 2017

    //platform.twitter.com/widgets.js

    • That’s nice! I guess one could do that at night? I failed miserably at getting anything worthy of not hitting the trash bin last night.Is there a ‘hold focus at infinity’ gesture in iphone 6+?. My screen taps seem to reset every time.

      I’ve done slo-mo before on a tripod with a remote shutter but those have all been during the day.

    • AllHailPresidentCheetoJesus

      Okay… That was awesome… Thank you for sharing!!!

  • CHeden

    Here’s a writeup I made of the 9-10-1999 T’storm outbreak in the Bay Area…which was the best one I ever saw in the Bay Area in the 60+yrs I lived there. The similarities to yesterday’s event are quite striking….including the date.

    ” 9/10/99 For most Bay Area Natives, 9/08 – 09 was the most spectacular lightning show ever seen in the Bay Area (yes, I did get some great video’s both here on the coast and from the SF Peninsula)…and at times rivaled some gems witnessed in Colorado and elsewhere. At it’s peak, the NWS reported 217 lightning strikes during a 15 minute period last night along the squall line stretching from just south of San Jose to off the Marin Coast. At that time, 6 different cells were active within my eyesight along I-280 along the SF Peninsula. Lightning was hitting the ground along the Peninsula’s bayfront near Belmont with aircraft trying to land at SFO between me and the lightning. I videoed 1 bolt which I thought hit a plane, but no such reports (fortunately). Tremendous cloud-to-cloud mosaics with dozens of filaments stretching sometimes 10’s of miles and lasting multiple seconds. Hail was reported in many locations, with a brief outburst in Pacifica around 4pm. A total of 0.15″ of precip in briefly moderate showers fell here, and over 0.75″ fell in the hills south of here. Because of the traning effect of the storms (axis almost perfectly S-N with zero W-E advection ) Pacifica had on/off lightning/rain for 15 hours…with lightning visible constantly all night in my area. The peak came at 0400of 10/09 when lightning repeatedly struck the hilltop/ridge directly to my south (about 1/4 mile as the crow flies – about an average par 5 in golf), with thunder arriving less than a second after the flash. With the echoing along the hills, it was clearly the loudest thunder I have ever heard. This event came as a total surprise to virtually everyone in weather watching/forecasting. Other than some high clouds associated with what appeared to be another in a long sequence of cool air upper lows hitting the coast from the SW and positioned off Point Concepcion, there was little sign of the low’s presence. Radar/visible loop analysis (hindsight), indicated that starting around noon of 9/08, moisture flowing up from the tropics (Hurricane Greg remnants) got caught in the upper low’s circulation and in 2-3 hours rapidly developed a very impressive T’storm line on the NE flank of the low in a line stretching from south of Monterey to just north of San Francisco. Due to the low’s slow easterly movement (none), the showers/T’storms started training right up the coast, mostly along the western Coast Range mountains. Close to 1″ fell in localized regions of the southern Coast Range This event has been reported in the media (CNN Live @ 0200 on 10/09 showing great lightening over The City) as the best/worst T’storm in over 25 years around here. I saw the one in 1984. This had it whipped hands down”.
    Excerpted from http://www.viewpacifica.com (with author’s permission).

    • Dogwood

      Yes that’s the one I remember, along with only 2 others 70-80’s.
      Yesterday was barely a blip in central San Jose. Some minor rumbles, all off to the north and east.
      Beautifully refreshing, but benign.

      The 1999 one, for me, was an actual electrical storm.

      Glad it produced elsewhere tho.

  • Shane Ritter
    • 82/83 El Nino baby (San Jose)

      As much as I am ready for summer to be over, I have read on here, Cheden I think, that stronger fronts in September are bad as it means the setup will result in a dry pattern when we get farther into fall/winter.

      I am not ready for a dry year yet.

      • Bob G (Gustine)

        I don’t see a correlation. I would chalk that up to coincidence

      • I still don’t know what a dry fall is vs a wet fall.
        Above average for SON?
        40% or more of season average for SON?
        Something else?
        Otherwise it’s just anecdotal IMO.
        I’m ultimately looking for causation.

      • Chris

        Sept 1976 frequent cold fronts
        Bone dry winter
        Sept 1987 a few strong cold fronts
        Bone dry winter.
        Sept 1989 two cold wet storms
        Bone dry winter
        BUT….
        Sept 1982 wet + Olivia remnants
        Ok 1982-83… need I say more?
        Sept 1996 frequent weak storms
        Floods of ’97

        I think wet Octobers is a truer sign of a wet winter.

        • Bob G (Gustine)

          Did it rain much last October? I don’t remember. It seems wet Octobers are a thing of the past.

          • FolsomPrisonBlues

            We got some around the Halloween week I think. I do not remember how much though.

          • Bob G (Gustine)

            I think the halloween storm for us was next to nothing. It is the only moisture i remember

          • alanstorm

            Last Oct saw a record amount of rain up my way

          • Chris

            Up in the Bay Area it did esp the central coast.
            I had 7.27″ and the average is an inch!

        • alanstorm

          2015-16 : nothing went according to forecast
          2016-17 : DITO

          It’s like trying to predict which way a rubber ball will bounce: to many variables.
          & don’t forget chaos/entropy.
          Oh, & unprecedented heating up global climate ….

          • Chris

            Wait and see, wait and see….

          • alanstorm

            That’s why it’s so exciting. (for us anyway)
            A real-time reality show that affects millions that changes like the….weather!

    • Bob G (Gustine)

      Interesting. The NWS yesterday said temps were supposed to rebound in our area to normal and even some above normal temps. This would change that forecast

  • Thunderstorm

    Walked outside and noticed that the lawn looked greener. Then remembered that one bolt of lightning produces 8 tons of nitrogen. Free fertilizer for farmers in mid west. We get more tonight then everyone will notice a green up. Read for round 2 definitely.

  • SoCalWXwatcher

    Still a ways out, but If this verifies, it’s definitely going to feel like Fall. Hope it does.

    https://uploads.disquscdn.com/images/ceed6a9fdc77ccec20ed66266fc85808d154a706fa744faf52da11552ab16d3c.png

    • Bob G (Gustine)

      Me too!! I’ve had enough of the summer heatwave already this year. This week is off to a good start. I am hoping we’ve seen the end of the 100 degree days

      • SoCalWXwatcher

        Glad things begin to cool down somewhat this week, and it looks like long range model trends are showing more seasonable or even cooler than average temps for a while at least through the 25th. I’m on board with that!

        • FolsomPrisonBlues

          I am totally good with cooler than normal. It will be a nice change!

        • Dan the Weatherman

          Since the heat started earlier than usual here in Socal, I have been wondering if we will cool down earlier than usual this year. That may be the case if this forecast verifies!

          • SoCalWXwatcher

            Looks like another warm spell after the 25th (hopefully a short one). I’m still apprehensive about the upcoming Santa Ana season.

    • Thirstier Nick (Santa Maria)

      That’s quite a vortex. Might see 60s for highs in the Central Coast.

  • Bob G (Gustine)
    • SoCalWXwatcher

      I hope Ken Clark’s call is right. I think the most honest call was Patzert, essentially saying they just don’t know.

      • Bob G (Gustine)

        I think how the SSTs in the east pacific setup this winter will have an effect, They are still changing

    • matthew

      I am calling for an early, cold onset of storms followed by a relatively dry Nov-Jan and a few “please give us some rain” storms in Feb-Mar. I will be riding my road bike in shorts in Jan/Feb. In other words, back to the drought.

      • Cap’n

        I threw my dart at the board and it landed on 93% of average precip with some good cold storms, yours landed on drought. Time will tell I guess. One thing is for sure, this is the most unique September I’ve seen since living here. Summer last Monday, intense late season summer storms, lows predicted next week that look more like late October early November. Who knows. I love this time of year because anything is still possible for a good winter. My elbow is still bugging at times for January shovel-fest.

        • matthew

          Going forward I figure if I call drought every year I will be correct about 80% of the time. The odds are with me.

          • Cap’n

            Aint that the truth. I’ve enjoyed these last days of any snow at this level, it will be folklore soon.

          • Yolo Hoe

            Your picture from Lola was a beauty — long may it last

      • Dan the Weatherman

        Socal is definitely due for a wet March. March has been incredibly warm and dry in recent years, especially 2015 and this year.

    • Hopefully Patzert was misquoted, again. LOL

      • SoCalWXwatcher

        “For this coming winter, however, with no El Niño in sight, he’s making a not-so-bold prediction: It’s going to be either wet or dry.”

        Yep, playing it safe. Kayak sales will be slow this year. 😉

        • The fact that Los Angeles received 131 percent of average rainfall the following winter — Oct. 1, 2016 through April 30 — and the Sierra Nevada received record levels of snowpack is inexplicable, he said.

          “Either we slip back into drought or we have a repeat of last winter,” Patzert said.

          —So we have a drought or another inexplicable year. That was the nit I picked :))

          • SoCalWXwatcher

            My money’s on neither.

          • Dan the Weatherman

            We will probably have something in between, not as wet as last year, but not drought conditions like 2012-15, either.

      • Bob G (Gustine)

        LOL. Brian A thinks the SSTs in the Eastern Pacific will be similar to what we had last year

    • alanstorm

      In other words, since last 2 winters were contrary to predictions, they have no idea.
      I put more stock in predictions & opinions on the WW blog.

      Maybe a trough /inside slider next week for Northern Counties?

    • Hollow Scene (Riverside)

      Drought periods are often punctuated by wet years, and last winter could have been that. I’m loosely betting on drought or slightly below average. I would like to test the Santa Ana wind theory out again. If fall is full of weak to moderate events, then drought; if we get some moderate to strong events then likely around average or above. We will see 😀

      • FolsomPrisonBlues

        SST’s aren’t unlike last year in the north pacific, other than lan nina more than El Nino on the equator. I have a feeling this year will be around average.

  • flyboy45

    https://uploads.disquscdn.com/images/c327cb680c8819a856775de8d151392f0ac5887f148981bcdd7ad26286cf5e32.jpg
    More signs of an early Fall. The SW monsoon ended rather abruptly in most of Arizona almost a month ago with the passage of a dry Pacific trough bringing killer westerly flow. This multicellular CB over the Jemez mts of NM was taken August 23, 2017. The last major moisture intrusion there, also almost a month early by my recollection.
    The southernmost tower is seen just pushing through what’s left of a dramatic pileus.

    • Hollow Scene (Riverside)

      Is all the thunderstorm activity in northern New Mexico and Arizona today not from the monsoon?

      • flyboy45

        Only isolated high-based in Eastern Arizona. Some leftover moisture in NM being acted on by disturbances moving out of the NW. Not your classic monsoon setup at all. This summer started out well in AZ but fizzled. In NM the moisture mainly came out of Texas on backdoor cold fronts, another setup not characteristic of the south to North flows out of Mexico.

  • Bob G (Gustine)

    Here is Howard’s thoughts about the upcoming winter:

    The key teleconnections are quite a bit different as compared with last winter. There is cooler than normal water in the Bering Sea, VS last years warmer them normal SSTA. The QBO has become East to West arguing for a deeper Hudson bay Low and the Pacific Decadal Oscillation is now neutral trending Cold for the west coast. This all argues for more meridian flow for the eastern pacific and across the CONUS vs zonal flow from the pacific last winter. It appears that from a temperature point of view, the Fall will become quite cold (November) with periods of Continental Air backing into the Great Basin at times this Winter. As far as precip, it is still too early for a call, but at the least, not nearly as wet as last winter. Colder storms will higher snow to water ratios seem more likely. AR events, although still quite possible in an ENSO neutral trending Cold, will be far fewer in numbers. Last winter we has some 15 AR events. Normal is about 5.

    • alanstorm

      ARs are welcome

      • Yolo Hoe

        1861-2?

        • alanstorm

          I’d be happy with 2016-17 although it was a bit on the soggy side

          • Yolo Hoe

            Careful what you ask for Mushroom Man — I remember those self portraits you posted at peak saturation

    • SoCalWXwatcher

      Meridional flow could open the door for some interesting cold snaps.

      • Dan the Weatherman

        I just hope we don’t have a year like 2006-07 that featured an epic mid-winter cold snap and very little rain. Despite the January cold, I didn’t like that winter because it was almost as dry as the Atacama Desert here in Socal. I would take a milder winter overall with more precipitation as opposed to a year with a lot of cold snaps and little rainfall.

        • SoCalWXwatcher

          I think that was the driest season on record. It was certainly the driest one that I can recall.

  • Bombillo1

    A most pleasant night sleep last night with the sound of rain drops and an occasional thunder clap. Unfortunately the bill came due and found this going on at our upper pond. Not much sleep penciled in for tonight. https://uploads.disquscdn.com/images/bc35a697d2953083577b6889438f0617f0e7c390bef5bdf66a15168bf8419644.jpg https://uploads.disquscdn.com/images/cd36eab469c816e6024405e62c1eae49043d822420d0c88324ae54f368753514.jpg https://uploads.disquscdn.com/images/fc1fd8083a4cd639f03081caea95347e2ba9c490316b4ab30ebe588698fe00e3.jpg

    • annette johnson

      Fingers crossed they get that under control soon. Thankfully your pond is nearby?!

    • Sokafriend

      Are they taking water from that pond? I searched and can’t find a reference to that fire by general description you gave.
      Until I read the long ,long list I didn’t comprehend how many significant fires are active all over the northern forests. Oh man.

      • Bombillo1

        Yes they’re taking water. 3 helicopters now, 1 tanker. Just east of Big Bend. Remote ground, no foot soldiers for this.

        • Tuolumne

          Just curious – when did the giant windmills farther east on 299 go in?

          • Bombillo1

            About 6 years ago the windmills went in. Aren’t they beautiful?

          • Tuolumne

            Pretty amazing. I’ve been in that region of the state a number of times, but hadn’t driven 299 all the way from Redding to Alturas until I drove to and from the eclipse last month.

          • Bombillo1

            That is also one of the main arteries to get to Burning Man. Hang a right at Surprise Valley and you are there. I am North of 299, tucked into a valley with several 6 to 8 thousand foot peaks. Pit River goes thru it. About 25 mi from Mt. Shasta.

          • Tuolumne

            Surprise Valley – now there is a really cool and obscure place!

          • Tuolumne

            Northwest of Tunnel Reservoir?

  • happ [Los Angeles]

    Fire containment is improving nicely as temps lower and rain chances increase. Over 2 inches of rain occurred on 9/15/15 from remnants of Dolores. This summer has similarities including easing the fire season in SoCal, thus far.

    Troughs are our friend
    https://uploads.disquscdn.com/images/349586925639ae469e1b6a893d88021c642e5f0fd2248cf0213f08a692972c09.jpg

    • Nathan

      those NW forest fires won’t be out until first big rains, no doubt. At least their intensity can probably be reduced. Low-intensity lightning fires are most definitely a part of the cycle up there.

      • RunningSprings6250

        They’ll be out in a week or two…

        • Nathan

          down, maybe, out, I doubt it…

  • Tyler Price (Carmel Valley)

    Is there really going to be more thunderstorms later this afternoon?? The skies are so blue and the weather is so quiescent ATTM in Monterey and as far as I can see..? It still feels downright muggy and very humid outside, but it doesn’t seem like there is going to be any thunderstorms at all.. not even the HRRR is showing anything for the central coast even though the SPC has a marginal chance for thunderstorms?! Am I missing something????

    • happ [Los Angeles]

      Glad that Monterey county received rainfall even in Salinas Valley. Humidity reminds me of the summer 2015 but even last summer was muggy. This year seems the worse and am sure there is plenty of data to confirm.

    • My guess is from the west/southwest as the COL comes inland.

      • Tyler Price (Carmel Valley)

        Hmmm I believe you are correct sir.. latest HRRR is starting to pick up on this and I do see cumulus starting to develop alas.. storms should be much slower moving today and it looks like a bullseye for the Monterey bay and possibly SF later this evening!! 🙂 super excited as it should be juuust in time for when I get off work later this afternoon.

    • Thunderstorm

      All the action is to the north. A slight build up east of Salinas and nothing over the ocean. NWS blew this one.

  • alanstorm

    1200 CG lightning strikes & 5800 in-cloud bolts for yesterday’s Bay Area event.
    Is this unprecedented?
    https://www.google.com/amp/www. sfgate.com/local/amp/Bay-Area-thunder-lightning-rain-storm-weather-SF-12189916.php

    • Sokafriend

      Sheesh. How could it not be?

  • Sokafriend

    It’s only 11:30 and we are already 8 degrees above forecast high. Forecasts have been off like this for over 1 month- since before the last heat event.
    Sudden cool down envisioned for tomorrow associated with a trough, with 10-20 degree below normal Thursday and cool through Monday.

    • 82/83 El Nino baby (San Jose)

      Do you know if your city or town has wide variances in temps? For example, in San Jose, downtown and areas north gets a sea breeze that my area does not. This causes my temps to continually be 10 degrees higher at home higher than what is is where I work and what is forecasted by the NWS.

      • Sokafriend

        Well yes, we do have fairly wide variances betwwen rhe coast and a few miles inland. But NWS accounts for that- and even still, our temps
        have routinely exceeded forecasts lately, especially a few miles inland.
        We’ve also had more than a few nights, early evenings on a 30
        foot cliff above the coast, with sudden and uncomfortable increase in temperature and humidity.. we’ve even turned on AC after the cooler late afternoon on the beach. It really is a different something.

      • Tuolumne

        The differences in summer weather in San Jose are revealed by the distribution of oak trees along creeks. Closer to the Bay where there is more of a sea breeze and the marine layer comes in more often, you find live oaks (along with the usual riparian trees such as willows). As you move farther from the Bay and it gets warmer in summer, you start finding deciduous valley oaks which don’t like too much of a coastal climate. You can see this on the Guadalupe River and its tributaries, for instance.

    • Dan the Weatherman

      I hope this week’s forecast cool down verifies because I am ready for some cooler weather for a change.

  • inclinejj

    Pacifica. 11:30 am 83.8 degrees. 47 percent Humidity Barometer 29.71. Looks like something is trying to move in from the South.

    • matthew

      75F/55% up here. The clouds are starting a serious buildup right now. I am guessing that we are 2-3 hours from the storm starting.

  • Jim

    Fog making a hard push inland along Santa Cruz County coastline…already in a couple miles in spots

  • Cap’n
    • happ [Los Angeles]

      60’s low 70’s currently surround Lake Tahoe

  • Quagmire Cliffington

    Hello old friends – Winter is coming!

  • Thunder98 (Santa Maria Valley)

    Deep Marine came in last night and it’s still hanging around and produced drizzle as well today.

  • gray whale

    rapidly developing Cb calv. looking NE from Gold Hill. Reminiscent of and about 5 degrees off from the King afire pyrocumulus 3 years ago (probably to the date)

    https://uploads.disquscdn.com/images/af1ea299e4e33aaa32afb8305e1d0d9cd41cd9f3325e4cbc6943209c37efcc72.jpg

    • happ [Los Angeles]

      beautiful shot

  • alanstorm

    KTVU Chan 2 noon news weather girl on today’s forecast:
    “……and that’s when we’ll see those thunderstorms pop up like yesterday”
    REALLY???

    • inclinejj

      Was it the Rosemary? Tall Brunette?

      • alanstorm

        Yesssssss?
        Not sure how you could be a “meteorologist” & not be frothing at the mouth over what happened yesterday & even the slimmest prospect of a repeat today

    • Maybe it was the way she said ‘pop’? Just guessing.

      • alanstorm

        I get it- ha ha.
        BTY- storms building all around me currently.
        Thunder rumbling constantly… 3pm will be GO TIME

    • lodule16

      “Weather girl”? What is this, Mad Men?

      • alanstorm

        Ok…Weather Human
        Soon to be Weather Droid

        • Nathan

          so catchy.

        • lodule16

          Already weather droid on NOAA weather radio… the brother of the bot who told you “your door is ajar”…

  • Thunder98 (Santa Maria Valley)

    So far I have seen 0.46″ of rain in September 2017, the average is only 0.16″. In fact this is the wettest September since 1997!

    • RunningSprings6250

      ?….

    • SlashTurn (Santa Barbara)

      I remember September of 97′ quite vividly with active subtropical moisture and electrical storms…that following winter was pretty good… prettay, prettay good.

      • Thirstier Nick (Santa Maria)

        Yep, I remembered that winter. This might be a good sign.

        BTW, my house recorded .61″ so far this month.

  • Thunder98 (Santa Maria Valley)
    • SacWx

      There has been strong agreement from climate models on a wet December for NorCal… anyone have any good analogs for this coming winter based on ENSO conditions?

  • V-Ville

    A few drops in Vacaville. Just enough to mess up the even layer of dirt on the farm truck. Clouds are gorgeous. Hope it continues and finishes the job.

  • GFS still trending even further Southwest – snow line is showing first real snows of the season in Tahoe now. Before it was just a dusting at mammoth.
    On another note, got some footage of the activity yesterday, got to my viewshed a bit late for any solid action – is the same spot, the peninsula, still going to be hammered or is it expected to shift east. And its incoming from the ocean this time right? Trying to prep for tonight ahead of the show.

    • rob b-Truckee/East Bay

      Steve Paulson mentioned he’d thought storms tonight would trend more to the Eatern part of the Bay Area.

      • Crap thats BAD for me, I have a few spots I can hit up when the bolts start dropping but I don’t want to get Tyler Priced, not all my tripods are carbon!!!!

        • Carbon conducts pretty well too. It splinters/shatters yet is so hot the splinters cool into a mass of threads.

  • Summit Steve

    Rain is coming down heavy yes it was on the drive from Kingvale to the Soda Springs.

  • Thunder98 (Santa Maria Valley)

    Youtube video of the Severe 2nd Thunderstorm that hit Santa Maria on Sunday. Constant Lightning and Thunder.

    • Wolfpack

      That’s very Midwest like. A Very rare treat for your part of California.

    • SoCal Al (El Monte-SGV)

      The guy was lucky since most of the lightning was c-c and not c-g. Standing outdoors (though under porch) is not a good idea especially with a huge tree next to you……though I must say my nerdiness, I would have done the same.

  • Rainmaker (San Jose)

    This morning, i made a call about no 90’s for San Jose for the rest of this year, its 91 right now. Temperatures were 6-7 degrees higher then predicted. That caught me off guard. However, we are still closing in on the fall equinox with a trough that will bring a lengthy period of well below average temperatures. In a couple of days overnight lows will drop to the lower 50’s; and GOA storms are returning for Northern California, times they are a changing!

    • Tuolumne

      That would be so nice to have lows in the lower 50s!

  • Cap’n

    Steady rain on 89 by Squaw. Radar shows another storm potent cell heading towards my house. Gonna have to start doping my dog up on tranquilizers at this rate.

    https://uploads.disquscdn.com/images/c35807f4a3d48ef86e01ebd178cfa5b1741a0e77899bc19418f327b4c4fee65d.png

    • rob b-Truckee/East Bay

      Forecast for next week looks like it will be fireplace season….highs in the 50s?! Fall is coming in fast and hard…..

      • Cap’n

        I’m sitting at 6 cords right now, with access to oak down in Auburn if I need more, I’ve got it stacked in places I never thought to stack. If there was ever a winter to start burning early I guess this would be it.

        • inclinejj

          I forgot if I told you this before. Buy some chicken wire about 1/4 and attach it with bailing wire to your fire place grate The chicken wire holds the hot embers from falling and your fire burns longer and hotter.

          • Cap’n

            We use a stove.

      • AlTahoe

        Perfect mountain bike weather. Hopefully it stays like this till mid Nov. Then it can start snowing.

  • Thunderstorm

    NWS still sticking to the forecast of thunderstorms this evening for the bay area. Very unlikely I think.

    • 82/83 El Nino baby (San Jose)

      Agreed. Nothing on radar in CA except the sierras.

      • Idaho Native

        A very strong push of fog has just spread inland across SF. Makes me doubtful as well for a repeat 🙁

    • It’s evolving exactly as depicted by the models. I would expect rapid develop between 5 and 8pm across the Bay Area.

      • Even with the fog flowing? You don’t think it will shift East or South? I wouldn’t even bother you if this wasn’t relevant – for safety and productivity purposes. Not a fan of being struck by lightning 🙂

    • Patience my friend.

    • SoCal Al (El Monte-SGV)

      They may develop a little further south of SF. The MTR NWS has this in their latest AFD:

      A handful of forecast models — such as our in-house Monterey WRF, HRRRX, HRRRX Ensemble Mean, GFS, and CANSAC WRF — all paint locally heavy QPF along coastal Monterey County south of the Monterey Peninsula from about 6Z to 12Z Wednesday (11 pm PDT Tuesday to 5 am PDT Wednesday). We`ll continue to monitor and evaluate the latest incoming forecast models trends.

  • Round 1 from last night, framegrab from a timelapse – wish I had time to drop video but I gotta get ready for the incoming stuff: https://uploads.disquscdn.com/images/c0f40cc0965a6a189cb604c292e7f78a18e6390d2fcbabb238b044920c21c925.jpg

  • alanstorm

    Monster cell spanning
    entire eastern Mendocino County swallowing Mt Sanhedrin over Willits.
    CONSTANT lightning & thunder, expanding my way
    https://uploads.disquscdn.com/images/5968d3f97d0ee2e2b8daeea8d71813227c54742af089ff8691316cc19a457b9f.jpg

    • Thunderstorm

      The low will miss the bay area but there is still moisture up your way.

  • Cap’n

    Severe storm alert just popped on the radio; where am I Kansas

    • happ [Los Angeles]

      No you are instead in Oklahoma; take cover a tornado is coming your way

      • Cap’n

        Absolute window rattling thunder but the rain is light at best, pretty dry storms so far. A mile or two to my west could be a different story.

  • Bob G (Gustine)

    The NWS in Hanford forecast the potential for some serious thunderstorm activity on the west side of the valley. So far the radar is quiet and there is nothing but sun outside

  • AntiochWx

    Still nothing on the radar for Bay Area, hope things pop soon.

    • inclinejj

      The fog is pushing right along the coast. Will probably move inland at nightfall. In Pacifica we have dropped 10 degrees in the last 2 hour. 84.2 at 4:30.

  • Great Winter of 2017 (SMC)

    peaked at 89 today with dew point up to 68 F, Heat index hit 92.2!

  • This doesn’t look good… isn’t this basically a sign of fugeddaboutit: https://uploads.disquscdn.com/images/c9bb5a7b0e1b75c745d1fa71adbca9f29473575a8195e548cb817215e9775058.jpg

  • I’m beginning to think nothing is going to happen.

    • Hollow Scene (Riverside)

      Wouldn’t these storms not be dependent on daytime heating but dynamics from the low?

      • I guess, but I don’t like seeing the marine layer pushing inland.

        • It has made the temp here plummet, and “cold thunderstorm” aren’t two things that go together, like Walrus Janitor, Buddhist Macaque, Candy Corn and Salad, or President Trump. See? Doesn’t make any sense!

    • Thunderstorm

      YEP!

  • Nate
    • So basically nothing tonight, but something tomorrow for the south/monterey bay

    • Rusty Rails

      Seems optimistic considering the fog will have been in place for roughly 24 hours by then unless the flow shifts.

      • This would definitely be an “on top of the marine layer” scenario, which is common during NorCal autumn convective outbreaks. Storms develop in a layer of elevated instability well above the surface, and do not depend in any way on daytime heating (in fact, “nocturnal convection” is partly the product of differential cloud top cooling that occurs after nightfall, which destabilizes the atmosphere further. There’s two ways to increase the temperature lapse rate with height: you can warm the surface, or you can cool the upper levels!

        • Fascinating, I recall seeing an event with an on-top scenario in the bay around 2011, a typhoon remnant hit the bay with the marine layer quivering beneath it. Dropped bolts all over the Peninsula and Marin Headlands.

        • Great Winter of 2017 (SMC)

          Why haven’t any cumulonimbus clouds initiated in the Bay Area?

        • Rusty Rails

          We shall see considering the same setup seems to have suppressed the big activity progged for this evening.

        • Chowpow

          Thats exactly what happened over Eureka last week, very cool setup!

    • CHeden

      The HRRR has been showing this all day….so pretty high confidence.

  • Great Winter of 2017 (SMC)
  • alanstorm

    By far the BEST lightning show in years for interior Mendocino Co, watched several dozen bolts hit this same area, apparently started a few small fires.
    Column of smoke going R to L from Lake Phillsbury area, maybe Butte Co, then spotted another around Snow Mtn.
    Looks like they have them under control, maybe due to downpours & high humidity.

    https://uploads.disquscdn.com/images/f38f069c87ee365ea52c801980166b4588937fab35e0958d9a420e182ee1cef9.jpg https://uploads.disquscdn.com/images/3fab66cf05d29458309513db70bd2c169bffa16751e34f2d08cb19fb1f01e440.jpg https://uploads.disquscdn.com/images/a6f7d60302867ab624e9202970be6060146766af5810efaeb74671a6c97c96a5.jpg

  • AlTahoe

    Today was supposed to be the big day thunder storm wise but nothing is getting going here in South lake. We have had some sprinkles and a couple rumbles of thunder but the cells are dying out really fast. Last night’s light show was amazing though.

  • Thunderstorm

    Would like to play poker with the NWS tonight. There bluffing!

    • Great Winter of 2017 (SMC)

      What?

  • Keiko the Sleddog (Mammoth)

    Can feel the thunder here in mammoth

    • Keiko the Sleddog (Mammoth)

      very scare

  • AntiochWx

    Seeing some the beginnings of cumulonimbus clouds off to the east, wonder if they will develop into anything.

  • Great Winter of 2017 (SMC)

    Intense thunderstorm over Mammoth and snowing on the Palisades and White Mountains where I was 12 days ago https://uploads.disquscdn.com/images/d254cc6af03819a077705c6188909bdcd3435067f4428d00f2b0d48d4f0ae3a0.png

  • Admode (Susanville)
  • Nate

    Here’s some video from last night. I was able to find a high point with an okay view of the Santa Clara Valley. The sheer amount of flashes was impressive–I’d estimate that I saw at least 1000 over the span of ~1.5hr, with rates anywhere from 10-20 per minute, most of the lightning being C-C. This was by far the most impressive lightning display I’ve ever seen in the Bay Area.
    https://youtu.be/1EHLvk8Hv3o

  • Dan weather maniac (ORINDA)

    Maaaaan I knew it!!! Best thunderstorms ever in the bay and I’m in NYC! So nice to see it all here after checking into the blog.

    I hope more comes tonight.

    I got this though, 9/11 remembered. https://uploads.disquscdn.com/images/37282cf226914669db3ed84f1cff78958f844b3eefe0233fb595ab6dc1764575.jpg

    • C M

      Don’t worry: NYC gets thunderstorms a dime a dozen so if you’re there all week, you’ll probably catch one or two.

    • Dan the Weatherman

      It looks as NYC has a chance of t-storms around Thursday and Friday if you are going to be there until then.

  • Charlie B

    A pretty good thunderstorm is headed my way in south Reno. It already has a very nice rainbow. https://uploads.disquscdn.com/images/5858a72586aaa5c068804b62775181e3d9e5255d5eb3c620b1e49e9c700d8ec8.jpg

  • C M

    Best thunderstorms I’ve seen in a while from 3-5PM in South San Jose and was hoping for a repeat today. However, skies have been disappointingly clear today but my app calls for thunderstorms from 1AM to 5AM. If you had to bet $100 on thundestorms or no thunderstorms at this time, which would you bet? Should I stay up all night to enjoy the storms or will it all be for nothing?

    • I think from looking at the trend on the Radar/Sat, yes they will come, however I’m currently grappling with the marine layer – trying to find a spot just outside of it to capture the show, not quite sure where the marine layer will tucker out at however, so I’m eagerly watching to see where this goes.

      • Great Winter of 2017 (SMC)

        What did we learn from this last thunderstorm outbreak: trust Daniel’s calls and the GFS is the one to trust for this event, so yes

        • C M

          Okay: I will stay up all night to watch but I do have an 8AM meeting tomorrow. Haven’t pulled an all nighter in about 5 years.

          • Cap’n

            Call Tyler’s guy Hector.

  • Craig Matthews

    Alto cumulus beginning to develop over the northern Santa Lucias this evening. As the upper level cut off Low approaches the central coast tonight, if the HRRR is correct, we could see rapid development of elevated convection and thunderstorms across the central coast,,,again. https://uploads.disquscdn.com/images/7495e77b9909eecfbf85439fa78e90d0c2a3a1304aef14e55c76c09f1aa466d9.jpg

    • Great Winter of 2017 (SMC)

      elevated, it didn’t pour when thunderstorms went over you?

      • Craig Matthews

        Nope it poured, just was very isolated and there was not much accumulation being it was very transient…as most elevated cells tend to be around these parts. During yesterday afternoon we had terrain induced convection which formed off the santa lucias, and then pounded us with lightning -thunder and about a third of an inch of rain in a very short time.

  • Despite the slight delay, I still think Bay Area thunderstorms are likely tonight. May initiate as soon as 1-2 hours from now south/west of San Jose, and further north overnight. The upper low is edging slowly eastward, and conditions are still particularly favorable for nocturnal convection tonight–which can take place even on top of a stable marine layer.

    • C M

      I am going to take your word and stay up all night and watch. My app says it will hit South San Jose from 1AM to 5AM which means risking no sleep as I have an hour commute and 8AM meeting tomorrow. Is there any chance it could hit me earlier like midnight to 3AM so I can catch a couple of hours of zzzz’s?

      • Cap’n

        This is a dangerous game you’re engaging in. Staying up all night almost ensures that it will be a bust. I say sleep and if the thunder wakes you up it was meant to be.

        • C M

          That’s what my wife is saying (She loves to poke fun at my weather obsession).

      • I’d sleep with a window open (so it there’s thunder it’d hopefully wake you up). 🙂

        • C M

          My wife doesn’t want me to sleep with our window open so I’ll sleep on the couch (I’m normally a heavy sleeper but more likely to wake up on the couch then in the bedroom (which has a very small window and no screen)

    • Rusty Rails

      Don’t stop believin’!!! ???

  • Great Winter of 2017 (SMC)
  • Great Winter of 2017 (SMC)

    Kind of made that my rain gauge decided to not work yesterday, had to clean tipping device and inside of gauge. 🙁 Got atleast .1-.25 inches of rain

  • Seeing rapid buildup near peninsula and altamont area, at least on radar. On the way to find a fog free spot, wish visual satellite worked at night 🙁 anyone know of any resource to finding the fog cloud top height other than like a metar/taf/AWOS etc, haven’t had much luck with those resources

  • C M

    Was yesterday the warmest temperature that San Jose ever experienced rain before? I do recall a small handful of summer thunderstorm events in the past but none on a day where it exceeded 90F.

    • Chris

      I rememeber seeing rain when it was 96 degrees in September 1984

      • C M

        I was born in 1986 and can only remember the weather from 1991 onwards 🙂

      • C M

        I wasn’t born yet

        • Chris

          Your parents should have had you sooner ?

  • cthenn
    • annette johnson

      So very cool. Awesome to see the big picture.

  • 805 Weather (Camarillo)

    Is it just me or are the mesoscale models beginning to have a hard handle the on the wrap around moisture associated with the cutoff low? These outbreaks have been helping sustain quite the boundary just offshore… https://uploads.disquscdn.com/images/776edb80872de40076a0eaadf45199ab9e02fa80c560291f940c5bb8e5f44f3a.gif

    • Tyler Price (Carmel Valley)

      All I know is I like the position the CoL is moving gives me some hope to see it moving toward the coast like that it’s setting up Monterey bay and SF bay in its NE quadrant and as the CoL getting overhead closer it brings with it the colder air aloft which should also help to spark off convection.. so it it keeps moving like it is toward the Bay Area like that something is bound to pop off sooner or later tonight! I’m feeling pretty optimistic we will see some showers and thunderstorms sometime around the early AN maybe that’s start to fire up around 11 pm or 12 am and last through the morning hours? We’ll have to wait and see..

  • Taz & Storm Master

    the models are hiting at some really chilly fall like air comeing down even no not in the forecast for the mts but with the chilly air comeing down we could see snow levels down too 6000 too 7,000ft in the mts if there any moister in the air

    • Eddie Garcia

      yeah both the gfs and cmc are agreeing that cooler air is coming. hopefully this trend continues

  • Taz & Storm Master
  • C M

    What is the ETA of the thunderstorms to South San Jose so I can set my alarm in case I don’t wake up to the thunder?

    • Henry

      What was the ETA for Irma to make landfall over Miami as a category 5 hurricane? I would not assume that everything predicted by forecast models will happen. Sometimes it is better if they don’t.

    • I wouldn’t count on it.

    • Thunderstorm

      Everything will now be south if at all.

    • Nathan

      Precisely 2:17:43 AM

    • Jim

      The HRRR still picking up on activity starting around 2am…we shall see !!

  • Bombillo1

    Fire that started last night has grown despite the all day assault. About 4 mi from the ranch. I have assured the family all is well and they have gone to bed. The dog and I are getting in the Mule to head up there now… https://uploads.disquscdn.com/images/8c89780b309f5c66e6c558e28f7e5cc70da6adf3732ffb2bcbed2e8123408c89.jpg

    • Jason Jackson Willamette

      Be careful there Bro. We’d hate to lose you.

      • Bombillo1

        Your kind thoughts notwithstanding, I would hate to lose me. We’ll see what today brings….

    • Sokafriend

      That’s a lot closer than I thougt. Let us know what you found when you’re back.

      • Bombillo1

        What I found is not good. I am hoping to hear the helicopters in about 4 hours. Going to start getting my stuff out into the pasture with all the sprinklers going.

    • Sokafriend

      So it’s reported at 100 acres now, in steep terrain.

      • Bombillo1

        https://uploads.disquscdn.com/images/6a009ed534796b0d38b8640c2ecca88c8e53a51758eae44a5be155d4c3425292.png

        Local fire chief says 500 acres now. It is growing with a fair 6 mph breeze, coming toward the ranch. PG&E has their Pit 4 powerhouse that would be the first casualty. My place would be the next structure.

        • That looks serious – are you at DEFCON 3 or 4?
          Weather West Lead Pulaski Party?

          • Bombillo1

            I’m at DEFICATE 10 if this thing is still coming at me by morning.

        • Sokafriend

          How’s it going?
          Light West winds under 10mph today. turning steady from South to 15 this evening.

          • Bombillo1

            Thanks for wondering. Winds started out from the south right from the get go, quite strong, and blew the smoke north. Much more resources today: skycrane, 5 other helicopters, several dozers now. Cal Fire truck came flying up the driveway about an hour ago with 2 low boys behind him with more Dozers. I thought I heard a bugle trumpeting and the fellow kind of looked like John Wayne.

  • C M

    Thunderstorm chances in San Jose have been diminished from 70 percent to just 30 percent at peak tonight.BUST! I’m going to sleep and not waking up til the alarm goes off at 6AM. Wife is telling me “I told you so!”

  • The only thing I see on radar, is a Clutter fest.

  • 805 Weather (Camarillo)
  • Scap

    The fog mist in capitola at least feels like a very light rain.

  • All cameras ready, even the thermal one…calibrated and temperature tested.
    This all but guarantees it will be a bust. https://uploads.disquscdn.com/images/7810fab6558b88c6782523b0b4efb7fc9ac3441440471a70e6590db29252e3b6.png
    Maximumbustbait.jpg https://uploads.disquscdn.com/images/c7f5fe794c538f5a6015fa9efdc9e89a136dd8ee97bb4c889123dbbd172986bc.png

    • 805 Weather (Camarillo)

      Sweeeet.

  • 00z shows a beautiful fall like pattern setting up.

  • Tyler Price (Carmel Valley)

    Whoa the weirdest thing is happening outside in Carmel valley right now.. the lightning over the ocean right now is somehow lighting up the marine layer here in Carmel valley?!? Never seen this before? I’m seeing bright flashes of light that lights up the marine layer here in the valley, but no sound of thunder and nearest lighting is out over ocean far from where I can see it.. with mountains impeding my view of ocean.

  • Tyler Price (Carmel Valley)

    I’m hearing thunder now!!! Lots of lightning flashes!! Sooo many I’m seeing them all from here since the marine layer is lighting up!! In half I stayed awake this is something I’ve never before seen!

  • Tyler Price (Carmel Valley)

    Holy weeeee cows!!! Constant lightning and thunder heavy rain joe too!!!

  • AntiochWx

    Possible T-storm now showing up just SE of Antioch.

    • AntiochWx

      Well so much for that, missed and tracking over Mt. Diablo.

      • From 4 to about 6:30, we were getting constant lightning in Brentwood. The last clap was the brightest and the loudest. A grand finale, if you will.

  • Jim

    Looks like some new cells are forming near Hollister/Gilroy area and some headed for Tyler again

  • rob b-Truckee/East Bay

    Thunderstorms are moving West from the Sac Valley now headed towards concord 680/hwy4 area. Lots of actin around Mt. Diablo the last 20 mins with multiple flashes and thunder rolls.

    • AntiochWx

      Yeah had another pop up shower after the first missed to the south. Nice surprise this morning.

  • Tyler Price (Carmel Valley)

    Here comes round 2!!! Constant thunder!!! Tons of lightning to my south east a lot more than what’s showing up on radar!!! Lightning every 2-5 seconds! And constant rolling thunder what a light show!! Incoming!! https://uploads.disquscdn.com/images/ddd8f5e70ade8a8325cf74e2458760210b21ae829f4e70336bf2eaeefd4e7a10.png

    • Yes! SSE of Morgan Hill. Monday night was s light show. This morning thunder too. Hope it moves up towards me.

    • Yolo Hoe

      Dude — radar just keeps lightening up for your area — been watching since 04.30 and the sustained wave pattern has been very cool indeed — your channeling of Hector has been a success

  • Jim

    Fog is lighting up here in Watsonville in southern Santa Cruz County…looks like it’s moving this way from the Santa Clara Valley

    • Jim

      Now starting to hear some thunder…

  • Great Winter of 2017 (SMC)

    Weather is a wierd who red thing, well until next time

  • Jim (Watsonville)

    How dare that cell die out like that !! Oh well, saw some flashes in the fog before it pooped out

    • Rusty Rails

      As I suspected last night the much hyped activity over Santa Cruz County never transpired. Watching that cell fizzle as it came over the hill was a sad sight.

  • rob b-Truckee/East Bay

    Second Round of action rolling through Clayton/Concord area. Right on schedule based on radar images.

  • C M

    Total Bust for the night lightning. Glad I didn’t stay up for nothing. Good news is there is some activity around the Gilroy Area. I am off to commute to my meeting from South San Jose to North Downtown. It will last from 8-10AM. If I’m VERY lucky, the cells might come up to San Jose around the time I get off.

  • Tuolumne

    Apropos of a recent discussion here, there were a couple of strikes this morning between Antioch and Brentwood, and a couple more within a few miles of the top of Mt. Diablo.

  • Tyler Price (Carmel Valley)
  • Thunder98 (Santa Maria Valley)
  • rob b-Truckee/East Bay

    NWS Reno discussion is mentioning snow levels….looks like Fall is coming to say hello.
    “….. Any amounts
    would be light, generally up to a quarter inch which could fall as
    snow above 7000-7500 feet. One other interesting aspect is that the
    lake effect machine could get going Tuesday night. Anomalously warm
    lake temperatures will support it provided there is little wind
    shear which is questionable at this time.”

    • Chris

      I swam in Lake Tahoe Labor Day Weekend!
      Very warm indeed!

    • AlTahoe

      If you zoom in to the top left side of this picture I took this morning, you can see the steam coming off of the lake. https://uploads.disquscdn.com/images/2e213a252c63de7bff674862232143be9323639a2fdb2da54d22d79bc446e5ee.jpg

      • rob b-Truckee/East Bay

        Could be an interesting week for Tahoe, I believe Oct 1st is the day most boats on buoys need to be off….with temps going below freezing there could be a quick trip for many to pull their boats off the lake.

  • BRP (Ventura)

    Just a quick gee whiz moment. September 23rd and 24th will be the only two of four days of the year that our sun sets directly due west at 270° and rises due east at 90° (here in VTA). When the kids were younger, I would make them take a compass outside on one of these four days to get a good perspective of what and where true West and East were, based on the sun! What a nerd…..

  • Thunder98 (Santa Maria Valley)

    The chance of rain next week will go far south as Santa Rosa, CA!

    http://forecast.weather.gov/MapClick.php?lon=-122.71925314748754&lat=38.44973096563575#.WblSctFlCUk

  • Thunder98 (Santa Maria Valley)
    • Thirstier Nick (Santa Maria)

      It’ll be a matter of time to see the leaves changing color.

  • FolsomPrisonBlues

    All rain for the Folsom area has been pulled for the next 10 days 🙁

    • Don’t fret it’s only September. I’d like a couple of storms to come through mid-October to get and keep the hills greening up.

  • Rainmaker (San Jose)

    the gfs 2m temp anomaly is beautiful. A large dark blue all over western USA. Bring it on Fall! 5-6 days out https://uploads.disquscdn.com/images/66102fc5014dbb42cc4626530be120c469a7ebafdfb9b3a1e548bd8bb8086064.png

  • jstrahl

    Got enough drops around 8AM to wet the streets in central Berkeley. Notable how lows have stayed above 60 deg F this month (except for one day).

  • Los Padres NF/ Piñon Pines
  • SoCalWXwatcher
  • Fairweathercactus

    Yesterday a lot of high and mid level clouds over the area. The air mass for the first time since May felt like it changed over to that more crisp fall air.

    Also I would not be surprised if Summer has 1-2 more tricks up its slevel coming into the end of September and October.

    • SoCalWXwatcher

      Long Range 12z GFS looks like it is hinting at a possible offshore flow event/Santa Ana setup towards the end of the month. (Thankfully it’s still out in model “Fantasyland” for the time being). At least we can enjoy some Fall-like temperatures until then.

      https://uploads.disquscdn.com/images/1ada460020c91282f0612371f0fed09d95e4e31912be7d84ba55fbe57148bab5.png

      • 805 Weather (Camarillo)

        For some reason I have a feeling we should keep any out for that later on ?. I’ve been itching at the possibility of a really crappy Santa Ana season.

        • SoCalWXwatcher

          I’m just going to enjoy the cool down, and hope that GFS Fantasyland heat wave is just a model hiccup. I’ll be more concerned of it gets within the EC’s 240hr window and both models show it.

      • Thirstier Nick (Santa Maria)

        Can’t be as bad as September 1-3. Bring it!

      • SlashTurn (Santa Barbara)

        Hopefully it’s “dry” heat from proggresive surface HP… Not that bad considering what we’ve been going through…maybe patterns like this lead to more cut off low entertainment with a steep jet through the Great Basin…

        • SoCalWXwatcher

          The problem with dry heat/offshore flow is the fire danger. Especially down here in SoCal. We’re bracing for Santa Ana season.

          • SlashTurn (Santa Barbara)

            It’s only a problem if there’s ignition…I have always welcomed Santa Ana season (especially at the coast)…it would clean out the stagnant SoCal air and make the waves have shape…being a former seasonal wildland firefighter, this time of year was the slowest for work and most Forest Service employees get laid off…From a statistical perspective, most large wildfires in Calfornia are in mid summer…The last destructive wind driven fire in Sept-Nov was 10 years ago in San Diego (Witch Fire)…

          • Jim (Watsonville)

            I worked in the supply unit on that fire…wished I had got a t-shirt from the vendors…one of the few fires i didn’t get one

          • SoCalWXwatcher

            I think we’ve been fortunate over the last several years. The worst fire storms in SoCal happen during the Fall Santa Ana season. Don’t want to see anything like THIS again:

            https://uploads.disquscdn.com/images/2af9b60e658b89d63918934c1c34be60b7ab1435a3af582d26e28f57ffa75563.jpg

          • SlashTurn (Santa Barbara)

            Sure that’s true, but “fire storms” here in Autumn are a very rare occurrence similar to a cat 4/5 hurricane making landfall….I’m just not the one to promote some kind of fear of Santa Ana winds especially when the only existence of danger is predicated on the fickle occurrence of human ignition. The winds signal a changing of the season and I quite enjoy them…

          • SoCalWXwatcher

            I wish I could enjoy them, but aside from tempting the pyromaniacs, they dry out my sinuses. 🙂

          • SlashTurn (Santa Barbara)

            Ya i’ve noticed over the years im in a very small minority of the dry offshore wind fan club…

          • EdInRanchoBernardo

            The 2007 fire was caused by downed power lines. So I guess that could be “human ignition” if one were to blame SDG&E. But the lawsuit going back and forth here pits SDG&E vs (act of) God (God = wind).

          • weathergeek100

            That image must be from either 2003 or 2007. I remember 2003- I was a senior in high school and school was cancelled for a week (we called it ‘fall break’). Much of San Diego had mandatory evacuation orders. Freaky stuff.

          • SoCalWXwatcher

            Yeah, that was 2003. Several bad fires, especially the Old fire, Simi fire & Cedar fire.

        • SoCal Al (El Monte-SGV)

          The huge upper trough will develop over the Great Basin and be too far east to provide cut-off lows over coastal Cali. More likely the seasonal “inside slider” type.

      • Hollow Scene (Riverside)

        Would that be a more of a fall style heatwave?

        • SoCalWXwatcher

          It looks like it.

      • Dan the Weatherman

        This summer started earlier than usual (mid June as opposed to the beginning of July) and the heatwave last week may very well have been our last “summer mode” heatwave of the season. If the weather is following the pattern that I think it may be, then an offshore flow hot spell would make sense at this point for late in the month and would be more like that of an October pattern rather than that of September.

  • inclinejj

    Pacifica 10:32. 65.1 degrees and trying to drizzle. Fog moved in overnight and it looks like it may stick around for awhile.