August 21, 2024

The Great Cooling is Imminent

 You better get your sweaters out.  And your umbrella.

You will need them as very cool temperatures are ahead, with Friday's and Saturday's highs around 15F cooler than normal.

Cool temperatures with bountiful rainfall over the region.

Some Northwest locations may cool to near freezing. And snow will return to the higher elevations.


Let's start with the accumulated precipitation beginning this morning.

By tomorrow at 5 PM, rain has accumulated over Vancouver Island and the coast.


Through Friday at 5 PM, western Oregon and NW California are soaked.



And then on Saturday, western Washington gets pummelled by heavy rain.  This is going to put a serious damper on forest fires west of the Cascades for the remainder of the season.

Looking more carefully at western Washington, the rainfall totals through Sunday morning are stunning (see below), with most of the region getting more than an inch.  August will come in with above-normal precipitation totals.


And then there will be the cold-- the Big Chill of August 2024.

For Seattle, weather.com predicts a high of 63F on Saturday (below) and the mid-70s in the Tri-Cities. The normal high for Seattle right now is 77F.


The UW's WRF weather forecast model shows amazingly cold temperatures on Saturday morning, particularly over eastern Oregon (see below).  

Temperatures dropping to the 30s are extensive both in eastern Oregon and in the Cascades.  Some cold spots will experience their first freeze of the season.


Daily cold records will probably be broken over the weekend.

And what about snow?

The total snowfall through Sunday morning shows flakes at the higher elevations of California, Oregon, Idaho, and Washington.


What is the cause of this cool/wet event?    

Answer: an unusually strong upper-level low parked off the Oregon coast (see upper-level map at 2 PM Friday).


Certain local newspapers have had strong headlines when the region has been warmer than normal.  Will they give similar treatment to the extremes that go in the other direction?


 




12 comments:

  1. The rain is nice but I'm looking forward to the warm weather by the end of the month and early September. 80's are showing up on my weather app.

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  2. So much for global warming. I read recently that it is well known we are well on our way to another ice age

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    1. One cold snap does not disprove climate change. And we both know that you did not read about another ice age.

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    2. I did read it. Book by E. C. Pielou that states we are heading into another

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    3. Chris I agree we could be also. Solar grand minimum is coming due.

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    4. Which book? I just looked up her bibliography and the only title that seems even remotely relevant ("After the Ice Age", c. 1991) is about the ecological changes since the last ice age, not a prediction of when a future ice age might occur. While I haven't it read it, one of the reviews of the book specifically states:

      "Pielou does not speculate on issues of global warming."

      In any case, Dr. Pielou was a statistician. While statistics can be useful in understanding population dynamics, it's not a substitute for energy balance models for climate forecasts. Nor are there statistical climate patterns similar to the roughly 100 year history over which we've seen carbon emissions skyrocket, and the 100 year forecast period that most climate models focus on. The historical climate cycles tend to run thousands of years, so a future natural ice age couldn't be counted on to rescue anyone from climate change for a long time.

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    5. Yes that's the book. Page 6. Pielou states "over the last billion years there have been 2 complete glacial ages and we are at the beginning of the 3rd..."

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  3. This is the high-season for outdoor activities in WA State. I'm thinking of hikers on the PCT and others, outdoor concerts, boating and so on. Many years ago I heard that PCT hikers headed for the Canadian border should cross the North Cascades Highway (SR#20) at Rainy Pass by September 1.
    There are many crews out working on trails. This will be a challenging couple of weeks for all these folks.

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  4. Hum! Not sure why I had to update my display name.
    Hi Cliff thank you for all the work you do!
    I was wondering what the lack of ground warming/lake water warming/general warming, we usually get this time of year might affect us this winter. It's not just cooler we're also not getting the sun radiating on things as well.
    From the south end of Lake Washington (Renton)
    Cheer!

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  5. The 12 UTC UW GFS run has the the 24 hour rainfall through 5 PM Saturday as over 2 inches at SeaTac! It will be crazy if that plays out.

    (lower for most of the rest of Seattle)

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  6. A search of "Seattle times weather" right now shows an article published two hours ago headlined "Seattle-area is on the verge of having the coldest August in more than a decade". So the answer to your snarky supposed-to-be-retorical question at the end there is yes.

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  7. It looks like the answer to your last question is "yes:"

    "Seattle area is on the verge of having the coldest August in more than a decade"

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