After mid-August reprieve, yet another prolonged California heatwave

Filed in Uncategorized by on August 25, 2017 3,560 Comments

A very hot summer thus far away from immediate coast; weak monsoon on western fringe

This summer has been among the hottest–and in some places the hottest–on record in most places, except along the immediate coast. (WRCC)

Summer 2017 has featured a recurring pattern across California, characterized by strong and persistent ridging just inland of the West Coast and prolonged, searing heatwaves across most interior portions of the state (and, indeed, across much of the American West). As has been widely noted, immediate coastal regions (within 10 or so miles of the ocean) have not been nearly as anomalously hot this summer due to the relative lack of the strong offshore winds typically required to bring hot temperatures to California’s characteristically chilly beaches. Nonetheless, warm ocean temperatures especially across the SoCal Bight have kept overall mean (and overnight) temperatures above average nearly everywhere. This combination has resulted in a rather curious situation where the majority of California is experiencing a “top 5” hottest summer on record, yet the majority of Californians (most of whom reside in densely populated coastal regions in the Bay Area and in Los Angeles/Orange counties) have witnessed comparatively mild conditions. Cities like Redding and Bakersfield are on track to approach or exceed all-time records for the greatest number of 100+ degree days in a single year, and it’s possible that other places will follow suit after another 1-2 weeks of prolonged hot weather to come.

While Arizona has seen an extremely active monsoon so far in 2017, most of California has seen much less mountain/desert thunderstorm activity than usual. (WRCC)

Another unusual characteristic of summer 2017 has been the relative absence of mountain/desert convective precipitation associated with the North American Monsoon. Interestingly, there has so far been a very strong east-west differential in monsoonal precipitation–with much of Arizona experiencing near record-wet summer conditions and some spots in the SoCal deserts experiencing near-record dry conditions. Part of the reason for this divergence is likely the persistence of high pressure on the western margin of the monsoon circulation, which has inhibited precipitation over most of California. There are still at least a few weeks left in the canonical monsoon season, and it’s often the case that California experiences a late-season surge in moisture/convective potential. Indeed, there is some indication that this very situation may evolve over the next couple of weeks (see below).

 

Upcoming heatwave will be prolonged, and will extend to coast in SoCal

Unfortunately, this post will read something like a broken record: there is more heat on the way, possibly record-breaking in some spots, and this time it may extend closer to the immediate coastline (especially in Southern California). A strong ridge will once again build directly overhead this weekend, bringing hot weather to nearly the entire state. Weak offshore flow will bring hot temperatures all the way to the beaches in SoCal, and some daily record highs may be threatened. Further north, coastal areas may yet again escape the hottest conditions, but another very prolonged streak of triple digit weather is expected across most of California’s interior valleys.

Current GFS forecast showing well above temperatures across California on three consecutive upcoming weekends. (NCEP via tropicaltidbits.com)

A “second wave” of heat may develop by next weekend, preventing any meaningful cooldown. Current model forecasts suggest this one may be centered further north, and could once again bring record-breaking heat to the Pacific Northwest. If this second wave evolves largely as expected, numerous all-time cumulative “temperature threshold exceedance” records (i.e., most days above 90/100/110 degrees in a single year) may be broken in the Central Valley. At present, there are not really any indications of average or below average temperatures heading well into September (which is actually prime coastal heatwave season in California).

Models have variously suggested over the past few days that a fairly robust monsoonal incursion westward into California–affecting the mountains and deserts, and perhaps also the coastal plain–will eventually develop during the second week of this heatwave. Also in the mix is the potential for some tropical remnants to become entrained in southerly flow aloft–and it’s getting to be the time of year when that sort of pattern becomes more likely. So far this summer, the global models have overestimated the westward extent of monsoonal surges, so at this point we’ll just have to wait and see how this evolves in the 7-10 day period.

 

A California connection to potentially devastating Hurricane Harvey?

A strong, persistent, and anomalous ridge over the Western U.S. will bring major California/PacNW heatwave, and prevent Hurricane Harvey from moving away from Texas. (NCEP via tropicaltidbits.com)

At the time of this writing, rapidly-intensifying Hurricane Harvey was approaching the mid-Texas Gulf Coast. There has been widespread consternation in the meteorological community over the past 48 hours regarding the potentially devastating impacts of this remarkable storm, which likely poses the greatest threat to human lives of any landfalling American storm since Hurricane Katrina. While the storm is currently approaching category 4 status (with sustained winds in excess of 120 mph), these destructive winds (and even the enormous storm surge associated with them) are actually not the primary concern associated with Harvey. Instead, the extremely slow-moving nature of this storm following landfall has the potential to generate truly astonishing rainfall accumulations across the Texas low country. Recent simulations from the ECMWF model, for example, are showing the potential for 50+ inches (over 4 feet!) of rainfall in less than 5 days. Needless to say, rainfall of even half this magnitude could produce widespread and devastating freshwater flooding–and the latest model forecasts would approach the largest rainfall totals ever observed in North America.

Aside from the potential for a weather disaster of national significance, Harvey is also interesting from a California perspective given the importance of the anomalous western ridge in “setting the stage” for a tremendous tropical rainfall event over 1000 miles away. Hurricane Harvey is already moving slowly, but will continue to decelerate and eventually stall over land within 100 miles of the Gulf of Mexico over the weekend–potentially remaining within 150 miles of the Houston area for the next 5-6+ days. This extremely sluggish movement will occur due to the combined influence of the powerful Western ridge (which will prevent westward movement and rapid dissipation over relatively arid West Texas) and the lack a of deep trough over the central U.S. (which will prevent Harvey’s circulation from being “picked up” by a larger passing storm). Thus, as the West Coast bakes amidst yet another prolonged heatwave, parts of the Gulf Coast may simultaneously experience an astonishing–and potentially devastating–tropical deluge. Stay tuned.

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  • CHeden

    WV shows our low over the Cent coast hasn’t appreciably moved at all today. I thought it would be on the move towards the SoCal coast by now….but like I said this morning, now not so sure. https://uploads.disquscdn.com/images/338700d32b1e7d6fb1991b201b0dfca87302f1cac77143e293499d1a0bd9ad09.jpg

  • FolsomPrisonBlues

    Has anyone else noticed that there seems to have been a lot more humidity this summer than most? Might just be me, but I am used to the hot and extremely dry summers we normally have.

    • jstrahl

      Yes, especially the last couple of weeks or so. The extreme heat ended Monday, but temps have remained relatively warm, and noticeably humid.

      • FolsomPrisonBlues

        Yea agreed. I went outside yesterday in the early morning and it was 68 degrees out, but 87% humidity =O

    • Admode (Susanville)

      It’s not just you.

    • CHeden

      Up here in the north Valley, it’s been lower humidity than usual. Seems like the cutoff line between humid and dry is just north of the Bay Area.

    • malnino

      Waaay more humid this summer, certainly in SoCal .. except for a bit of a break in the 1st half of August, monsoonal schmutz and moisture has been more or less constant. Still steamy here in the LA Basin, but nothing like the 110° and 60% (or more?) humidity from last week. Yikes.

  • AlTahoe
    • Huff (Anaheim Hills)

      Awesome! Kinda looks like fall has begun in the Tahoe region.

    • SlashTurn (Santa Barbara)

      No pollen problems for a while.

  • jstrahl

    CNN just now: Irma likely to hit Keys with 160mph winds, i.e. Cat 5, Cat 4 to affect much of southern Florida, including Miami.

  • Charlie B

    One of the kids left a half eaten piece of Dominos pizza on the picnic table out back and it is now a soggy mess after a rather intense thunderstorm here in Reno. This is a perfect example of nature polluting garbage.

  • MetaGhost (Berkeley)

    just visited fl511.com to view traffic cams in Key West. If you go to the cameras for the end of the road way west, you still see cars driving around.

  • alanstorm

    Last Vegas: INCOMING!!
    All kinds of flash flood watches for the Eastern Mojave, my favorite Kelbaker Rd area getting HAMMERED. Dry lakes will be full!
    I pity anyone camped out there now.
    Looks like Last Vegas may see some serious FLASH FLOODING in the next few hours
    https://uploads.disquscdn.com/images/c5c513f59a88698b2ee15d16c9a68d6373af81963af4d2812f0797a8929a1faa.gif

    • Dan the Weatherman

      I wonder if Zzyzx Rd. is getting some action?

  • Very interesting setup for Sunday across most of SoCal. Could see some coast-moving strong to severe thunderstorms if the stars align. I may have a blog post tomorrow if things still look on track for a significant event…

    • Bombillo1

      When does Northern California get a very interesting setup? My patience is not without limit..

      • Admode (Susanville)

        The nerve of the weather making you wait. >:(

      • CHeden

        We got ours in the north Valley Tues. night and again Thurs morning. Both were “maverick” events. Couldn’t have been any more “interesting” IMHO> LOL!

  • PRCountyNative

    End of the world – latest sign of the apocalypse?

    Weirdest cumulus cloud ever?

    Firecane?

    Looking about east from near Craig’s house.

    https://uploads.disquscdn.com/images/df72d4b347d258dcd512e00e1d19f2d7d831c782d85854ed625466da5d3f7ecf.jpg

    • malnino

      Tank? Warhead on a launcher? Giant turtle, maybe?

    • alanstorm
      • PRCountyNative

        My one is acting like smoke, but looks like a cloud… I’m perplexed.

        I would think I could tell.

      • Admode (Susanville)

        It looks like it’s pumping it’s fist in solidarity.

        • alanstorm

          Only to be dissolved by the winds of divisiveness moments later…..

      • Dan the Weatherman

        That cloud does look like a dog believe it or not, with the tail upright in the back and its nose and mouth pointing upward!

  • molbiol

    There is a lot going on this weekend. Below is the latest from NWS Los Angeles. Looks like Las Vegas is going to be active all night into Saturday and now the radar shows convection offshore of San Diego….

    “At this time, the models are showing significant moisture and
    strong instability moving over the area, with a potential of
    strong thunderstorms forming Sunday afternoon through Sunday
    night. The storms may be strong enough to produce wind gusts over
    50 mph, hail, heavy downpours, and flash flooding. The flash flood
    risk will be highest over the foothills and mountains, and around
    recent burn areas. In addition, dangerous cloud to ground
    lightning will be possible over both land and ocean areas.”

  • Nate

    Mexico’s quake last night was unusual in both its mechanism (extensional in a subduction zone) and the size of its tsunami for its depth. The Berkeley Seismo Lab has an interesting writeup on it:

    http://seismo.berkeley.edu/blog/2017/09/08/a-rare-quake-made-even-rarer.html

    • Nate

      It’s also interesting how long (4-6 min) and strong it was in Mexico City. This is primarily due to amplification from the old lake sediments that it’s built on, but it’s also because the earthquake ruptured directly towards Mexico City, sending the bulk of its energy to the NW.

  • Bombillo1

    Embarrassing revelation. So little loss of life in Mexico from humongous EQ was due to their Earthquake Early Warning System. Many were able to get out of their homes and save themselves from the falling debris due to the notification. The Mexican system has been in place since 1993!! We’re just now beta testing ours? What the hell, gringos can’t even make a decent fish taco.

    https://phys.org/news/2017-09-mexico-quake.html

    • molbiol

      Three words:
      “Money, Money, Money”
      In this country we prefer to wait for the shit to hit the fan and pay billions of dollars rather than invest a fraction of that in preventive measures that ultimately will save money in the long term. Unfortunately formulas describing the PMF of large earthquakes in California yield probabilities too low to be worth the investment

      • Bombillo1

        Money you say? How do you explain the fish taco problem?

        • molbiol

          That also comes down to money but opens up a whole can of worms (no pun intended) that I don’t think is appropriate to discuss on this blog

        • Sokafriend

          I totally agree with you on the fish taco dilemma- hardly anything better than a good marlin taco made right..
          One of the pioneers of a mega popular fish taco stand in Rosarito shared her secret batter recipe: Krusteaz..:) so not kidding.

        • Jason Jackson Willamette

          Del Taco and a lot of other drive thru taco places that served really good fish tacos keep closing to make room for, wait, here it comes

          BURGER PLACES! grrrrrr——

      • Admode (Susanville)

        Exactly. The oroville dam comes to mind.

    • Hollow Scene (Riverside)

      Are there any geological reasons why?

      • Bombillo1

        Area around Mexico City is VERY active geologically. Volcanoes and plates galore. Much more so than Ca. It was in their best interest to get this done.

        • Nate

          It’s easier to implement in Mexico too–the general population lives further from the nearest seismically active area than we do, so they have more time to process data and send out a warning.

      • SoCalWXwatcher

        Here’s the warning times given a couple scenarios in California. San Francisco would have 1-2 minutes warning for a magnitude 8 or 9 quake up near Eureka. Los Angeles would have 1-2 minutes warning for a magnitude 8 quake along the Southern end of the San Andreas.

        A Loma Prieta-type quake would only give San Fran a few seconds warning, if that. A rupture on the Newport Englewood fault underneath Los Angeles, or a repeat of the Northridge Quake would afford almost no warning, for residents there.

        https://uploads.disquscdn.com/images/f1f291d38bb2a9268a869f6cba7541a4ca0a2cb3bb05a92d224b68ad5a5ca318.jpg

        • Bombillo1

          Maybe there is a god, I accept your wager Pascal. SF and LA are most in need of a good culling.

          • SoCalWXwatcher

            Yep, the big 8.0 a couple hundred miles away isn’t the scariest threat. It’s the 7.0 right under our backyards that will do us in. Only warning will be flashing Earthquake Lights discharging around town, assuming it’s about to go off at night, and you just woke up to take a leak and noticed the lights.

            “Earthquake lights have already been used to help predict quakes. Just before Italy’s L’Aquila earthquake in 2009, a man in his kitchen saw bright flashes of light. Because he had reportedly read about earthquake lights before, he moved his family to a safer place.”

            http://news.nationalgeographic.com/news/2014/01/140106-earthquake-lights-earthquake-prediction-geology-science/

          • Nate

            The smaller (and arguably more dangerous) faults are almost always overshadowed by the San Andreas. The Puente Hills Thrusts of this state aren’t well known by the general public.

  • Cap’n

    While not the rodeo ride that Al and other parts of the basin got today, this is the third day this week getting a steady, light/moderate soaking rain. Tue: .3″, Wed: .2″ and today .3″ and counting. It was summer on Monday, and I think fall is here now. I’ve been up here 11 years and I don’t remember ever contemplating covering up my wood stash the first week of September. Who knows what this will lead to.

  • Thunder98 (Santa Maria Valley)

    The Sun was literally out for only 35 Minutes today. Very gloomy for September.

    • Great Winter of 2017 (SMC)

      Yesterday or the day before it was cloudy the whole entire day between the clouds related with the Low of the coast and the marine layer

      • Thunder98 (Santa Maria Valley)

        That was Monday I think?

  • Sublimesl

    IS it me, or does Irma look like its about to make landfall in Cuba..weaken then brush the West Coast of Florida? Disaster deferred?

    • SoCalWXwatcher

      Its Southern Eyewall is pummeling Northern Cuba, but apparently it is intensifying at the moment. I wonder if it will lose some punch when it makes that turn towards the Keys.

    • Bombillo1

      If it enters Camaguey its innocence and billfold will be lost. I never got mine back..

  • SlashTurn (Santa Barbara)

    12k freezing level in the eastern sierras right now…Palisade glaciers getting in on the action.

    I’m ready for winter! https://uploads.disquscdn.com/images/0a8a1ccca482fd587b9dd0462c3d4627a7833727cdc961699e9a119260d7ca2a.jpg

    • Cap’n

      I figured we’d see some dustings up high next week, looks like earlier! I’m ready too.

      • PRCountyNative

        Ready!!

    • matthew

      Nope. Not ready for winter yet. I want autumn first. I want to see highs in the 60’s/70’s. Lows in the 30’s. Slow changing of the foliage to fall colors. We were cheated out of spring. I do not want to lose fall too.

  • Thunder98 (Santa Maria Valley)

    Dew Points are finally in the 50’s!

  • DelMarSD
  • Great Winter of 2017 (SMC)

    Weather channel showing 60-80% chance of thunderstorms in my area Monday Night, suprsingly the weather channel is good at predicting when there will be precipitation but not how much

  • RunningSprings6250
    • Hollow Scene (Riverside)

      I just had some nice convective showers over here!

  • Tyler Price (Carmel Valley)
    • alanstorm

      Boulder City & Stateline have been under FLASH FLOOD ADVISORIES the last hour.
      Looks like it’s currently dumping in Las Vegas metro

  • Tyler Price (Carmel Valley)

    Very cloudy with steady drizzle from Carmel to the Monterey bay this evening.. accompanied by cool temperatures.

    • Craig Matthews

      I was just through the mouth of the valley about half hour ago and had to turn my windshield wipers on because of the drizzle. Smelled great on the roads. Hopefully we will get some real raindrops this time around later this weekend and early next week with the cut off Low.

  • Craig Matthews

    Last evening was the final of several consecutive evenings of spectacular sunsets in the Monterey Bay area. https://uploads.disquscdn.com/images/d11e83e16a41eb8968525d2161e4dccdd37dea5a7c23c2cdc8c69c66000403c8.jpg

    • Dan weather maniac (ORINDA)

      Spectacular!

  • Wolfpack

    When does Irma make the right turn North? So far this trend is looking better for Florida’s east coast.

    • alanstorm

      Maybe Miami not getting the brunt, but SW coast is now looking at a 10ft storm surge, which should cover a good portion of the entire area!
      Really unfortunate

      • tomocean

        Looks like Irma and Jose may both intensify to category 5 storms in the coming hours. That is just plain nuts the amount of energy those storms have.
        Hopefully, Irma takes even more time to turn and misses Florida altogether!

      • Wolfpack

        I’m just wondering if there’s a slim chance it doesn’t make that turn and continue her westward track into the central g.o.m?

        • alanstorm

          Like Katrina, it’s all about when it makes its northward turn.
          Sounds like it’s a done-deal for the fate of alot of real estate down there, marching right up the entire state.
          Geez Louise ?

        • Bombillo1

          Maybe doesn’t turn, continues into GOM but then does a Fugiwhari slingshot with Jose into Miami. There is a true Shakespearean outcome.. Daniel’s Grey Swan.

      • weathergeek100

        Yup. That’s basically the flattest place in the entire US. It’s even flatter than Miami (I read that the elevation in parts of Miami reach a whopping 20′). The Everglades, Naples and Fort Myers are basically screwed.

        • Crank Tango

          My aunt and uncle in Cutler “Ridge” (Miami) are at six feet, about a mile and change from the water.

    • Bombillo1

      Right. Cuba getting it in the shorts right now. Probably bought the Miami Dade line too much. Camaguey and now La Habana? # 3 and #1 most populous cities.

    • weathergeek100

      In a way, it could be very bad news. If it parallels the west coast of Florida with the eye right offshore, it may have trouble weakening and wreak havoc from the Everglades to Tampa and beyond.

    • Thunderstorm

      Buresh from talking to the tropics blog says, it has to slow down to make the turn north probably late tomorrow. Maybe it will completely stall, the water on the south side of Cuba is much warmer, lot of extra fuel there.

  • Rusty Rails

    This morning Netflix dropped a 4 episode season of “Fire Chasers,” a doc covering the 2016 fire season from the perspective of Cal Fire, LA County, etc crews. I’m part way into episode 1 and the imagery and access is pretty amazing.

  • alanstorm

    Reed Rimmer talking about “mini-vortices within the eyewall” detected in Harvey….
    Reminds me of the mini-vortices observed in big tornadoes

  • Great Winter of 2017 (SMC)
    • Bombillo1

      What a crazy exercise in capriciousness. No steering mechanism whatsoever.

  • DelMarSD

    Had some nice light showers. Hopefully more on Sunday!

    • Dan the Weatherman

      It clouded over here in Orange late this afternoon, but it didn’t rain. I am hoping to see some rain this weekend, though!

  • MetaGhost (Berkeley)
    • Jason Jackson Willamette

      What happens overnight is critical. Irma has taken a southwestward turn over the past 6 hours. It’s eye is now almost entirely over the northern Cuban coast. This is not the mountainous part of Cuba, that in the Southeast of the island. So what degrading effect this has on the storm is yet to be determined. I’m hopeful this turn of movement toward the SW will continue, and spare Florida.

      Here’s my favorite phrase regarding the future.

      We’ll see –

      http://www.ssd.noaa.gov/goes/east/carb/flash-ft.html

      https://uploads.disquscdn.com/images/9947b8b81e6ae5e11246ef80daca918d2183a5b7ab0acb2e9704384fe06f59ed.jpg

      • Great Winter of 2017 (SMC)

        It looks to be in position to move back out to sea to the NW

      • Thunderstorm

        I don’t think being over Cuba will weaken it at all. The water to the south of Cuba is much warmer also looks to be doing another eye wall replacement. Lots of energy and fuel on the south of Cuba. Still think it will stall and get stronger tomorrow.

  • John Curtis
    • What’s your prediction for Norcal in the Winter?

    • max

      Where is the Curtis fog? From a brethren in the Ojai Valley

      • John Curtis

        As you know my fellow Ojaian, it is non-existent. Check back in on October 15 for my winter prediction.

        • max

          I will be looking forward to your prognostications. We Have had some fog down in the hinterlands, if I recall.. Great light show over the Mountains the last couple of nights. My neighbor put his tin foil hat on , in case it was a UFO crashing!!

    • Thunder98 (Santa Maria Valley)

      Santa Maria will be in a favorable spot once again

  • Sokafriend

    Great little shower on Baja as we drove in – even more spectacular cloud draped moon radiating a soft buttery glow over Chula Vista an hour ago.
    Beautiful late summer night in the southlands.

  • Cap’n

    A buddy of mine and his wife hiked Mt. Whitney on Tuesday and caught a little weather action. All eyes on Irma tomorrow, I’ll be off the grid until Sunday night, afraid of the images I’ll come back to.
    https://uploads.disquscdn.com/images/ed1093a5d6cd5a6b42e3d971002faa94024de817d670b164d0cb5249fc921d3c.jpg

    • Jason Jackson Willamette

      Looks like Mars!

  • Jason Jackson Willamette

    My last post for today/night, I promise!

    First outer bands of Irma seen approaching the keys from the south. Tomorrow will be the day when we find out Florida’s fate….

    https://uploads.disquscdn.com/images/2bdadbf242c59113a6bfd34e69f424d321c12827fe9e092dff33019647622ecb.jpg

    • annette johnson

      I enjoy your posts! Yes, many of us sitting on pins and needles…

      • Jason Jackson Willamette

        Thank you Annette. Isn’t this comment site a blast? Love to share and pontificate like I know what I’m predicting, hahaha. Predicting the weather is as old as cave men (and women)… Those who get it right 50% of the time are elevated to godlike status. In modern times that success rate has surged to 60% +/-

        Have blessed day!

        • annette johnson

          Thank-you and Lol! It is a blast, especially with all the different personalities. Different ages and backgrounds but yet we have the weather obsession in common!

  • SolarWinds56
    • Jim

      Sure gives a good picture of just how big Irma really is..

    • Thirstier Nick (Santa Maria)

      I sure hope Jose will move north through the Atlantic. Two hurricanes hitting the mainland in a short period of time is bad enough.

  • Bombillo1

    Look at this strange: a. Attempt at eye wall replacement right over Miami b. Bombogenesis that is not taking place at mid latitude or c. What? https://uploads.disquscdn.com/images/8061cccc969f9134e2996c161ff462c3d86d13c1398da52b4520ceab66a24b60.png

  • Thunder98 (Santa Maria Valley)

    A decent chance of Thunderstorms on Sunday and Monday again

    http://i.imgur.com/add9dzf.jpg

  • Yolo Hoe

    Just got word from Miami colleagues that they have dodged the bullet — storm shifting west and they should only be hit with Cat 1 winds — flooding still an issue from surge — now the worrying shifts to colleagues in Tampa Bay Area, etc

    • Chris

      My cousins family with a newborn baby fled to Naples.
      Now they are in the bullseye!
      Also, looks like the mountains of Cuba tore into the hurricane. Winds “only” 130mph now

      • Jim

        Saw that too…thought oh good not as bad then…then read it will likely restrengthen to a CAT 5…going to be ugly

    • MetaGhost (Berkeley)

      That’s really premature. It still has the potential to reach either FL coast and still an opportunity (albeit small) to re-strengthen.

    • matthew

      I have friends in Venice who decided to stay put based on the forecast of the storm tracking on the eastern side of the peninsula. They are now in SYP mode.

    • cthenn

      The storm surge forecast is down for Miami as well. Combined with potentially lesser winds, it does appear the impact may be dramatically less than the earlier forecasts.

  • Rusty Rails
  • MetaGhost (Berkeley)
    • Jason Jackson Willamette

      I’m waiting for the turn to the north. Irma’s trajectory west seems to be difficult to break, since it’s been on that track since it formed late in August. It’s like Newton’s first law – “His first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.”

      That external force has been weak, caught in the summer/fall duldrums of weak steering currents.

      Irma may well not turn until it gets out into the GOM, well west of FL. Of course, then where does it go? Katrina all over again?

  • CHeden

    As I was mentioning last evening about the possibility, overnight our CoL has not moved at all towards offshore the SoCal coast…and in fact seemed to shift a tad more north over the immediate Bay Area. Assuming the low stays put, Tahoe will again be in the cross-hairs today as well as the rest of the Sierra. The low’s location will also favor possible squall lines to form SE of the low and bring a chance of localized precip to SoCal. Should convection break out within one of these squall lines, it’s possible rains will train over a given area and result in much higher amounts.
    Regardless, the upstream kicker should help push the low (wherever it winds up) east on Tuesday/Wednesday, with Tuesday being the most likely day for widespread showery precip….some of which could be on the heavy side depending on the amount of tropical moisture the CoL starts to entrain.

    https://uploads.disquscdn.com/images/b4f6e4db3e78f77c45dce912263e981a66418deafc4b36cae04d2ee9f72ba6d3.jpg

  • 805 Weather (Camarillo)

    All Euro members showing exactly what I’ve been worried about. Irma is reaching its warmest water its had available in this region and it’s in the worst possible position to do so due to the lag in Cuba. Since Wednesday I was noting this area of water was .5°C-1°C higher than the water Irma was thriving in at the time (still at Cat 5 when I made mention), unfortunately the elephant in the room is that Irma was generally forecasted to begin shaving off a category from the point it hit Cat 4 yesterday by most weather agencies, only the NHC was being more conservative which is good IMO. The ugly side to all this is that the models were showing a possible re-intensification of Irma over the Straits due to this bath water before making it’s Florida landfall… Euro’s members now put this into full perspective this morning. From what I can see this morning, there is some slight drop in the SSTs in the Caribbean since Irma has been in the vicinity. https://uploads.disquscdn.com/images/66e83b6bcb5a60aabddbb04caacd04f00e1519725ff48aee53adef47a532f271.jpg https://uploads.disquscdn.com/images/2abc6c8828fbd48d5602f91dece5939dd03089fe57bf2f47b14f0b5e767001ad.png

    • CHeden

      Worst case scenario is the core of Irma just skirts the west coast of Florida, with the NE portion of the eyewall raking the entire coast. With the warmer SST”s off Tampa, it’s logical that Irma will be feeding on those higher TPW’s as she moves up the coast.
      IMHO, the wild card is how much dry continental air will get pulled in from the NW which will tend to weaken Irma before the trough starts to lift north.

      • Hollow Scene (Riverside)

        I have relatives that are riding it out just north of Tampa in Tarpon Springs. Yikes! I thought being on the West coast they might be a little better off, but now that doesn’t look like the case.

        • CHeden

          No, it doesn’t.

      • 805 Weather (Camarillo)

        Same here, however the SST’s below Irma do not care… They will overpower any shearing that may intrude. She is a beast of her own now.

  • Blue__Bear

    Irma is breaking records:

    — Highest ever Accumulated Cyclone Energy (ACE)
    — Longest period (37 hours) of sustained winds over 185 mph

    Both directly attributable to warmer-than-normal ocean and air temperatures. Manmade climate change is a major contributor to the warming.

    • Jason Jackson Willamette

      No argument here. Irma is mankind’s child. Who shall claim her?

      • RunningSprings6250

        I will.

  • Jason Jackson Willamette
    • Jason Jackson Willamette

      My thoughts are not how much damage Irma does to Florida, but how the models all got it wrong, which would bode ill for future evacuation orders.

      • CHeden

        IMHO, it’s premature to cast doubt on the model’s based on precise track forecasts. Seems like it’s just a matter of minor timing differences which is having a noticeable impact on Irma’s forecast track…..a possibility all the pundits have been cautioning about for many days. Other than that, Irma is behaving pretty much as expected (i.e. really bad). Note that while Miami may not see the heaviest of Irma, it is already getting clobbered from the initial outer bands. IMHO, it would be foolish for the east coast folks to get too complacent.

      • Hollow Scene (Riverside)

        What did the models get wrong?

        • AllHailPresidentCheetoJesus

          Everything…

          • tomocean

            Not really. They were amazingly accurate. Since last Tuesday onward, they’ve had south Florida bracketed. They’ve ALWAYS said not to pay close attention to the exact track, since it could deviate by 100-200 miles (which it has). They’ve also been very close on calling the intensity. They NEVER said it would be a Cat 5 on landfall in Florida, always a high Cat 4, which it is on track to do.

          • annette johnson

            Better safe than sorry. Even if Irma doesn’t do exactly what the forecasts predicted, there will be some destruction somewhere in Florida. It’s just too big.

    • Bombillo1

      This was really a Cuban hurricane. Interesting that the big storm had no particular affinity for water and just as easily tracks over Cuba instead of warm water.

      • CHeden

        It really didn’t track “over” Cuba. The land-sea interface kept it on a coast-hugging track….bad news if this trend holds true once Irma starts nearing the Florida west coast.

        • Bombillo1

          My thought was that if land or even the land/sea interface was a real impediment to the storm why did half of it drift over the Cuban land mass? The storm was not ushered back to sea by the encounter. I think everyone was looking at the warm ocean between Cuba and Fl and thinking that would have to be its natural course.

  • alanstorm

    Has Irma made the turn north yet?
    (checking here first)

    • CHeden

      See above.

      • alanstorm

        Got it.
        Weatherwest Breaking News link

  • CHeden

    Irma’s core looks like it’s pulled ever so slightly off the north coast of Cuba. The eye is still very much intact, and enhanced rainrates are appearing within the northern quadrant of the eyewall. Too early to say for sure, but this may be the start of the expected NNW turn of Irma towards Florida. Also note the initial bands moving over Miami and further north up by Cape Canaveral. The rain band(s) are training over the same area, and are getting some significant rain and winds already.
    Here’s a still image as well as a link to the loop. https://uploads.disquscdn.com/images/be0683667f37b7d9c226a59ba464187888faefd1f4347773960c9c8bd7326764.jpg
    https://weather.com/weather/radar/interactive/l/USFL0316:1:US

    • Wolfpack

      I saw that as well, also the infrared show rapid cooling of cloud tops around Irma’s southern eye wall. She may be a cat 5 once again.

  • Wolfpack

    I know it’s a long way out but did anybody else notice what the 12z gfs is doing with Jose?

    • matthew

      Pulling a Sandy?

      It also has Irma at 897 right over the keys.

    • Darin

      NHC discussion had Jose swirling south east for a short bit at 96H. I have no idea what that means. I can’t imagine it looping and then recovering but just the idea of that is disturbing.

  • AllHailPresidentCheetoJesus

    My goodness Irma really fell apart… Wow… This is a major concern for the “next time”… People won’t listen as well and won’t heed the warnings… This just feeds into science deniers… Meterology desperately needs to find the balance between getting the word out and not over hyping… Each time this happens, the masses lose just a little bit of trust…

    • matthew

      Weak troll, bro.

      • AllHailPresidentCheetoJesus

        It’s not a troll, it’s reality… I have family in FL who are allowing this to feed their anti-science agenda… This is dangerous… I had an uncle tell me this is the last time he evacuates… Ever. Says he can’t trust the forecast and it’s being overhyped to fit the “liberal climate change agenda”…

        This isn’t a joke.

        • CHeden

          “Liberal Climate change agenda”? You gotta be kidding.
          Maybe the authorities should have kept their mouths shut, is that what you (and your Uncle) seem to be suggesting?

          • AllHailPresidentCheetoJesus

            No, I’m not and until you guys realize the deep seeded mistrust of science on the right, this only gets worse.

            These are not my views, I’m just relaying my families take and I can assure you they are not alone…

          • CHeden

            You’re right. How depressing it must be that your “family” is so entrenched in such politically-motivated poppy-poop….yet I’ll bet they’ll be the first one’s in line for FEMA (i.e. the dreaded Government) support.
            Right up there with flat earthers and we didn’t land on the moon.

          • RunningSprings6250

            Wait, we didn’t?

          • CHeden

            LoL!
            You can’t fool me.
            I was there.

          • tomocean

            Then they will drown. Their choice to ignore it.

          • thebigweasel

            I’ll note that Governor Scott, who has been doing a masterful job of urging people to get out of the way of what is likely to be a catastrophic storm is in fact, one of the biggest climate change deniers around, one of the first to make it a firing offence for government employees to use the terms “climate change” or “global warming.”
            So will your family decide that Scott was secretly a Al Gore minion all along?

    • CHeden

      As mentioned below, it’s WAY premature to write Irma off this way….as well as any “eroding” of confidence.
      There are >90F SST’s Irma will be encountering within the next 24 hrs off the Key’s, and again off Tampa/St. Pete and re-strengthening is very likely….which the model’s have been predicting all along. Please do not make such definitive statements without a thorough analysis and data to back it up.
      If you check out the recent radar’s I posted, Irma certainly doesn’t look like it’s “fallen apart”…and in fact the eye looks like it is re-intensifying as it moves away from the Cuban coast.

      • AllHailPresidentCheetoJesus

        That’s great except the average Joe doesn’t care about analysis and data… They see they’re being told the world as they know it is about to end and so they react accordingly only to find Irma has fallen apart and it doesn’t take a genius to see that on radar/satellite…

        • It definitely has not fallen apart…probably still going to make landfall as cat 5 in FL. But the track has just shifted slightly west, so practically that spares Miami a catastrophe. Perhaps not Ft. Meyers or even Tampa, however.

          • AllHailPresidentCheetoJesus

            Thank you for the reply Daniel and I want to reiterate my post does NOT reflect my view. I’m simply relaying what I’m being told by family who are there and see what appears to them as significant weakening on the visible loops.

          • thebigweasel

            I have a friend in Tampa, and she is very definitely not blowing off the coverage of the storm as “over hyped” she mentioned on another group that even if it did fizzle locally, she would much rather be scared and ready than complacent and comfortable.

          • 805 Weather (Camarillo)

            Been telling people this! Unfortunately I hate to be that guy in the crowd.

        • CHeden

          Not the average Joe.
          My impression is the vast majority of people in harm’s way utilize all available information before making life-saving decisions. Only a fool would wait until it’s too late to take action. Just ask the first responders in Texas about those who put themselves and others in jeopardy by clinging to such rubbish.

          • AllHailPresidentCheetoJesus

            Hear you 100%

  • RunningSprings6250

    I dunno – for every, “Irma is weak” post there is a “Irma is stronger” post.

    ????

    • Rusty Rails

      I certainly know which one to scroll by.

    • thebigweasel

      That’s because like all storms, it fluctuates.

    • matthew

      It is good to know that the great WW tradition of calling BUST! 24 hours before the event is alive and well.

  • happ [Los Angeles]

    Perfect pattern of troughs/ some rainfall across the state in extended forecast. What are the chances of a cooler than average September?

    • Thirstier Nick (Santa Maria)

      Zero percent no thanks to the Labor Day weekend heat wave. At least the highs will remain near average for much of September.

  • Great Winter of 2017 (SMC)

    Storm of 9-15 feet is now expected on the Southwest Florida coast and now Irma is started to strengthen again as deep convection is firing around the eye! https://uploads.disquscdn.com/images/8ee643efbb08dae3bc2095e5c2a96de1a60759f558ede9ade72af42197813cff.gif

    • Great Winter of 2017 (SMC)
    • Wolfpack

      She’s gaining again. 5 again before landfall?

      • Great Winter of 2017 (SMC)

        I think so, but the NHC is being conservative rn

        • CHeden

          The million dollar question now is will Irma briefly stall over the highest SST”S off the “Keys” (~ 91F)?

          • Great Winter of 2017 (SMC)

            *billion dollar question

          • CHeden

            I stand corrected.
            $$$$$$$$$$$$$$

    • alanstorm

      Looks like it has a nose for the warmest water

  • CHeden

    To conclude (hopefully) a spirited thread below relative as to how some people view meteorology and science in general….which is regrettably in the form of absolutes for too many…. I’d like to commend the bulk of the main-stream media and gov’t officials who have been managing these recent events (Harvey, Irma, et.al). For both Harvey and what we’ve seen so far of Irma, the PRIMARY message that’s been communicated is the unpredictability of these type of mega-events….and here’s the data to support what/why it MAY happen, and why you must prepare NOW for the POSSIBILITY of being in harm’s way. Whenever there is a 75% chance of something happening, that also means there is a 25% chance of nothing…which is a very difficult thing to communicate or comprehend by the general public….especially when money appears to have been wasted and people inconvenienced. Yet, only two weeks ago Harvey caused $190 Billion in damage but a “relatively” low loss of life occurred mostly due to preparedness. How soon we forget, or worse, lesson not learned.
    These type of catastrophes are no longer the fantasy of some obscure model, but have become a true reality….and how we respond TODAY will serve as stepping stones for future improvements in how to deal with the consequences.
    Lastly, lest we forget that Science and Meteorology are not entities (as a noun) unto themselves. They are processes (as a verb). They are the process mankind uses to seek and gain knowledge, and hopefully make positive contributions to the human cause….such as telling folks to get away from the water when it may rise 15 feet by tomorrow.
    Personally, if I lived in Florida right now, I’d want to know these things. Maybe I’d stay alive, too (or maybe not).

    • tomocean

      I really appreciate that the debates here don’t devolve into name calling shouting matches. That is a remarkable thing to find on the Internet now.

    • srfrgrl1

      Nice to hear a voice of reason here, too. I have family in and my mother has a condo (which was once my grandparents’) on the beach in Naples…yikes. I knew I could come to this site to get honest viewpoints. Growing up in Chicago, I spent many spring breaks with my grandparents when Naples was far less populous, and I remember there were markers all over the place that “commemorated” the destruction hurricane Donna caused in 1960. It’s a scary thought that Irma could be far worse than Donna in scope, size and in a much more populated and developed state!

    • AllHailPresidentCheetoJesus

      I agree with your take 100%… I just wish there was some way I could convince my family that there are no absolutes here and being safer rather than sorry is always the way to go.

      • 805 Weather (Camarillo)

        We are all hoping for the best, it’s obvious this is a two-edged sword.

    • 805 Weather (Camarillo)

      Fine words CHeden. Completely agree with your takes. As long as we continue to battle skeptics with facts they have no choice, but to either shut up or listen. This is a serious test for the way this region’s people think of storms. The ugly idea that is very much alive in all of this as a whole is that the people of the Peninsula who aren’t affected as roughly as their neighbors might give the ol’, “We made it, we can make it through any storm!” BS we know so well with unprecedented events like this… Especially when you have social media as a driver for that.

  • Sokafriend

    Cuban national weather service radar:
    http://www.met.inf.cu/asp/genesis.asp?TB0=PLANTILLAS&TB1=RADAR&TB2=../Radar/01Casablanca/csbMAXw01a.gif

  • SoCal Al (El Monte-SGV)

    Still hoping for some exciting weather here Sunday to wash away all the accumulated dust from a rainless summer. The set-up is still there for the potential of at least some measurable rain. The CoL currently off the central coast is expected to retrograde south/southwest and bottom-out off northern Baja with the HP center moving west. All the ingredients are coming together.

    Flood Watch
    National Weather Service Los Angeles/Oxnard CA
    538 AM PDT Sat Sep 9 2017

    …FLASH FLOOD WATCH IN EFFECT FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR PORTIONS OF SOUTHWEST CALIFORNIA INCLUDING RECENT BURN AREAS…

    An upper low just off the central California coast will drop southward today and tonight, and will be located about 300 miles west of northern Baja Sunday morning. Mid and upper level flow across the region will become southeasterly on Sunday, and will transport copious amounts of monsoonal moisture into SouthernCalifornia. In addition, the atmosphere will become increasingly unstable Sunday afternoon and evening. As a result, there is a chance of showers and thunderstorms across much of the area from Sunday morning through late Sunday night.

    • happ [Los Angeles]

      My location missed out of any of the remnant Lidia moisture last weekend; would love to get in on some showers this weekend.

  • Officially working on a post for this afternoon.

  • rob b-Truckee/East Bay

    While some may debate if Irma is underperforming or suck…looks like a semi-pro surfer was killed trying to ride her waves. Which makes me wonder why parents on tv today would be taking thei per kids to the beaches in FL to take pictures, the lack of respect for Mother Nature/water sometimes amazes me. FYI DIRECTV customers can watch live coverage on channel 361-2 from FL stations.
    https://twitter.com/deadspin/status/906589538365186050

    • Darin

      Or.. adults driving at tornadoes live tweeting and taking pictures. To be fair, pro surfers and weather chasers are probably the more informed about the risks.

    • cthenn

      Sad he was just a teenager, and surfers (the good ones) are very experienced in big conditions, but I’m finding it very hard to feel sorry for a person who would willingly go out in extreme conditions like this.

      • This happens in Skiing and Surfing – “conditions are gnar bro!” – and then they were never seen again.
        I ski in Blizzards frequently but it’s like there’s people out there looking for avalanches to fool around in – and then I hear about people trying to surf in hurricanes and tropical storms, it’s this same itch that kills skiers, who are occasionally surfers themselves.

        Is there some sort of survival gene? Because Darwin isn’t isolating it.

    • CHeden

      Thanks fer the heads up.

  • mattzweck
    • Wow…cat 3+ up the entire west coast. Just 20 miles west of that centerline would be very bad for Tampa storm surge…

  • Hollow Scene (Riverside)

    Quite a storm complex in the Colorado river valley. I hope everyone gets off the water! https://uploads.disquscdn.com/images/f487b9a82f3d53449a6061c32e1289d2e0fb4b1984bb2833fb26f21c0a0091cc.png

  • Fairweathercactus

    Hurricane katrina had rapid weakening before it hit. I think this hurricane might do the same.

    • Either way if its just offshore with 150mph+ winds the storm surge is going to be extremely damaging. But hopefully it weakens, however with the extremely warm water I don’t see any reason why it would.

    • That is extremely unlikely in this case. In fact, there is near unanimity among hurricane models of a 24 hour period of rapid reintensification prior to landfall–very possibly back to cat 5 winds.

      • Aaron W. (Paramount)

        looks to be rapidly intensifying right now…. think it will get back to cat 5 status by tonight imo.

    • Darin

      Much of Katrina’s damage was due to levee failure. Timing, wind speed, water volume, exogenous factors e.g. zoning laws, and more factors determine the damage. Category strength is strictly about wind speed. Sandy was an category 2 at landfall, look at how that turned out.

    • Great Winter of 2017 (SMC)

      U seem to often downgrade situations

  • Who Killed Kenny Strawn?

    Just a couple of days ago, it looked like Irma was going to hit South Florida as a cat 5 +++. Cuba has torn her down to a 3 and it looks like she will “only” hit Southwestern Florida as a plain cat 5 while barely giving Miami cat 1 winds. Instead of annihilating South Florida, she will cause total devastation around the Fort Meyers area. 140 mph winds and a storm surge that will literally drown all the barrier islands.

    Meanwhile, the latest GFS shows Jose making landfall where Sandy did in 2012, except he is a cat 3 upon landfall (cat 4 shortly before). Sandy was a cat 1 upon landfall. Imagine how devastating a cat 3 would be in New Jersey or New York. We are talking epic disasters for the East Coast.

    • Is this the account formerly known as Carp?

  • 805 Weather (Camarillo)

    RadarScope picking up on a velocities of 145.4 mph right now on NW outer wall of Irma…

  • Fairweathercactus

    It is nice to see the desert plants getting water on days like today.

    • Hollow Scene (Riverside)

      Looks like some may be getting washed away!

  • 82/83 El Nino baby (San Jose)
  • inclinejj

    My wife’s cousin came here from Italy and wanted to spend a summer or possibly a year in Tahoe. She thought Incline Village was too old and too slow a lifestyle. She moved to Key West Florida met a guy there and settled.

    Being she is from Northern Italy she is deathly afraid of earthquakes but considers hurricanes, just part of life in Florida.

  • RunningSprings6250
  • cthenn

    I always find it hilarious when the weather channel people are all bundled up wearing safety glasses (or in Cantore’s case, a batting helmet) while doing their broadcast, then in the background some tourists in shorts and flip flops stroll by.

    • RunningSprings6250

      Or the videos of deadly winds and then cars drive by…

      • cthenn

        Haha yup

    • Brain buckets are good to wear. If you’ve ever been blindsided by a palm branch you’ll never leave home without one.

      What could happen is the flip-flopped person gets slammed by a palm branch and then run over by a minivan while the driver is distracted by the live feed…or live streaming facebook

  • Scott Turner

    Ominous looking sky from the PCT north of Lake Morena this morning around 6. A line of storms tracked NNE a few miles to the west. Only got a few sprinkles. https://uploads.disquscdn.com/images/79a2961f82917f78066590962165d98b079ba24d039a9eec4f672b552f4abe75.jpg

  • cthenn

    It’s this thing gonna turn?

  • molbiol

    A surprising amount of towering cumulus in Lancaster. This afternoon could be more interesting than I expected

  • Tyler Price (Carmel Valley)
  • RunningSprings6250
    • Hollow Scene (Riverside)

      That thing looks angry

  • Thunderstorm

    Looking at the visible pic of California right now one would think this was a strong el-nino forming.

  • mattzweck
  • rob b-Truckee/East Bay

    Irma sending some big waves into Iey West, these poor structures don’t stand a chance.
    https://twitter.com/mattgutmanabc/status/906633313674305536

  • MetaGhost (Berkeley)