Sunday, January 12, 2020

Snow is Coming Today to Western Washington, But Not Too Much for Most

I am going to go against one of the rules of the click-baiting online world.  I am not going to even hint there is going to be a big snowstorm over Puget Sound land.  Yes, most of you will see some flakes, but for most the ground will be barely whitened.

As we shall see, a highly transient Arctic Front/convergence zone will bring a few hours of snow showers, with totals ranging from a few tenths of an inch near the Sound to perhaps 1-2 inches in the far eastern suburbs.

I am going to show you some forecast snow totals....but keep in mind there is lot of uncertainty regarding the exact distribution of snowfall.

The latest super-high resolution (1.3 km grid spacing) UW WRF forecast (below) for 24-h snowfall (through 4 AM Monday), shows light snow (~1 inch( over NW Washington, with 2-4 inches over the northeast Olympic Peninsula. Most of Seattle is around 1 inch, with some heavier snow east of the city.  LOTS of snow in the Cascades.


But you should NEVER depend on one forecast in such situations.  The UW high-resolution ensemble forecasts, with many forecasts, shows that at SeaTac there is a lot of uncertainty, with the best estimate (the ensemble average) about .7 inches.


Over north Seattle near Magnuson Park, the average forecast is about an inch

And near Lake Sammamish and Issaquah, nearly 2 inches--but again lots of uncertainty.

The temperature forecast remains the same: huge cool down tonight (see plot below).

The National Weather Service has pulled back a bit on snow totals, now going trace to 1-2 inches around Seattle.  Enough snow to enjoy, but not enough to cripple the region.  Most of the snow will fall before 10 PM, so SDOT and WSDOT has the overnight hours to prepare for the commute.


56 comments:

  1. Is that a convergence zone setting up over Tacoma in the 24hr graphic?

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  2. "SDOT and WSDOT has the overnight hours to prepare for the commute"

    Nice call for action!

    Right now (11 AM), NWS is forecasting for tonight 2-4 inches over "North Seattle WA 47.71°N 122.32°W (Elev. 302 ft)": "New snow accumulation of 2 to 4 inches possible." It could be that they err on the side of caution to get people prepared, or it may be their "call for action" to the city.

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    1. Reporting in: WSDOT trucks are active spreading salt on Capitol Hill and Downtown Seattle. One just drove by me and noticed the salt earlier downtown. Woot!

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  3. As you so aptly described in your wonderful book, The Weather of the Pacific Northwest, snow is one of the most difficult types of weather to forecast here. So to see such fluidity this close to an event is no surprise.

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  4. Ahh well, much ado about nothing it sounds like.

    Shame, as the hi-res models were going for 5 inches over Bellingham as recently as yesterday.

    That said, temps at noon have just taken huge dive (5f in 1 hour) in Hope, BC which means the Fraser outflow is about 1 hour away from Whatcom County. If there is enough moisture hanging around, who knows what might happen...

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  5. Cliff, please use your weather controlling capabilities to ensure that there is enough snow that I can work from home tomorrow. Thanks in advance.

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  6. What will this mean for the next couple of days? NWS and weather.com both indicate a bigger snow event Wednesday, but still only project 1-2 inches max- and even then, only about a 40% chance of snow to begin with.

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  7. Cliff, just curious, is Whatcom County still expected to be hit harder?

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  8. Looks like it's shaping up to be a nice sunny afternoon. Sorry, Seattle. You are going to have to go to work/school tomorrow. This seems like a go big or go home caliber bust. About those watches....

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  9. When will you let us know what to expect for Wednesday and Thursday? Eagerly awaiting news of what we might see later this week!

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  10. Currently 39 degrees and raining above Hood Canal, broken clouds and not much wind at all.
    Watching the maps as snowfall here can outperform forecasts.

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  11. How about the lowland snow for Wed and Thurs? Are we still looking at possibility of some REAL snow later this week?

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  12. Any theories about the hood canal region?

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  13. We just had 10 - 15 minutes of heavy sleet or freezing rain in Lake Forest Park. Rooftops, yards, and roads were white. Luckily, the roads are still warm and everything is starting to melt (minor slush).

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    1. Freezing rain doesn't make things white. It's called graupel.

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    2. I call it "snain". Snow + rain. Snain.

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    3. In skier vocabulary, graupel is different from freezimg rain--but I am nit-picking.

      Right now, a lot of people are trapped on Stevens Pass waiting for the road to reopen. WSDOT is busy clearing heavy snow and multiple accidents.

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  14. Cliff, can you comment on the east-west band of much higher snowfall forecast stretching from Tacoma towards Buckley?

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  15. when this stuff freezes, it's going to be ugly out. Stay home people.

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  16. Big wet flakes falling in the Shoreline/Edmonds border. Hearing same over in Lake Forest Park from a friend.

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  17. Redmond Ridge is also currently getting sleet or graupel. It started about 1:30pm. Roads are slushy & grass is white.

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  18. Snowing in east lynden currently.

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  19. Yes, there was a flurry of flakes in east Lynden for perhaps five minutes. Then back to rain and currently at 3pm it's merely wet, high 30s, and no wind. Winter storm & high wind warnings still in effect. We'll see...

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  20. Pretty serious snowfall a little earlier and now as well here in Clearview, where Highway 9 crosses the hill from Snohomish to Woodinville. But then I often say “we ARE the Convergence Zone” during weather events.

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  21. It started snowing about two hours ago here in north Lynnwood. We have about 1-2", and it's still snowing at 4:30 PM. It's close to being too dark to see how much more will fall, so I guess morning will bring more clarity.

    I hope the people on the streets are finding shelter in this frigid weather in store for us this week, if not longer.

    Thanks for all you do, Cliff!

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  22. Hopefully, this leads to another snowtopia in February.

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  23. Every once in a while, when you don't really expect it, the Seattle area gets a savage snowstorm.

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    1. Yeah which is why this one is probably a dud but some minor event prediction will turn into a MASSIVE one

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  24. Outflow is just now beginning around Sumas, where the temperature has fallen 10 degrees in the past 15 minutes. Otherwise no snow and no cold in Western Whatcom County yet today.

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  25. Dumping in S. Bellingham right now. Looks like the arctic front has formed over Whatcom County.

    About 0.5 inch in 20 minutes or so!

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  26. The squirels and their fluffy tails helped me predict this... Two inches and coming down hard here in S. (Central) Everett, near Boeing. Like I stated in the previous post, we will get 2 to 4 inches of snow, maybe more.

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  27. no snow yet in bellevue and looking like none overnight... what a terrible forecast :/

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    1. Interesting. There's been snow on the ground in Kirkland since the early afternoon.

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    2. Yeah I'm thinking Seattle/Bellevue might get something around Wednesday but that's looking increasingly less likely

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    3. 3 inches in Maltby. Started snowing around 2pm Sunday afternoon.

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    4. Yep, great forecast, ended up with around 4 inches in the Lake Sammamish area of Bellevue/

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  28. Cliff, The updated snow forecast is good news for Seattle--just enough to enjoy!

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    1. This comment has been removed by the author.

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  29. About 4 inches 1/2 mile SWof the Everett Boeing plant, from Lynnwood North to Boeing all is fairly white, with plenty sticking to the roads. DOT out in force trying to keep arterials and highways clear, still snowing as of this writing.

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  30. Micro-climates are interesting. We have over six inches on our farm just North of Monroe as of 8:00 tonight, with more big flakes coming down like there's no tomorrow.

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  31. I love the different types of comments on here. Basically it’s people saying:

    - look how important I am by telling you about the weather at my house.
    - bring on the snow, as much as possible! Who cares that 80% of people in the region hate it and can’t drive in it, I just love it until I don’t.
    - Cliff Mass is a god. I love him so much. He’s the reason why I get up every morning! Have my babies, Cliff Mass!!!

    So, to that end, just want everyone to know we have 3 inches currently at my ranch, and it’s a blizzard. Snow is awesome but I hate driving in it despite snow tires and 4WD. And yes, I love Cliff Mass. Had a few classes with him while at UW, seems like an okay guy. I did laugh when he yelled at someone for asking a question about Al Gore and if climate change is a hoax.

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    1. ... huh? You call out people who share how much snow they got and then do that exact thing. You additionally throw out a statistic (80% hate snow) which is incorrect just based on common sense if you've lived in the region. Seems you just want attention

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    2. this is the best comment I've ever seen

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  32. The light snowfall this evening which left an accumulation of less than an inch (little, if any, on paved surfaces - soil temperature is still around 40F) at my location in NW Bellingham appears to have come to an end for the time being. The temperature has fallen to 25F from an early afternoon maximum of 42.6F. Outflow winds are steady and possibly increasing in strength but have not, at this point, been strong enough anywhere in Western Whatcom County to justify the High Wind Warning which has been in effect since noon. Perhaps NWS might consider creating a sub-category of headline for which the particular weather event is surrounded by scare-quotation marks to distinguish between an event for which significant impacts are actually likely vs one for which significant impacts are conceivable but highly improbable. Thus, today's headlines would be 'Winter Storm Warning' and 'High Wind Warning', rather than Winter Storm Warning and High Wind Warning. I would prefer this alternative headline scheme so that I'm better able to calibrate my excitement:indifference ratio.

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  33. Mill Creek has gotten 5 inches so far and its still coming down

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  34. You can't be too hard on the newsies. Weather in this region is for the lack of a better word...challenging. Ridiculous might be more applicable term. The mountains pick winners and losers. Drive literally one street over and its a different weather outcome. This area (Central Kitsap Hood Canal area) got a meager dusting, thanks to the rain shadow. Those same obnoxious mountains created an 8 inch snow dump 30 minutes away. The whole county's schools are closed but there is nothing for the kids to play in here. They will be indoors and annoying.
    Winter in THIS neighborhood has been pretty dull and under par for most everything. Notably rain. Other areas will look back on this winter as memorable. Again we are talking a mile or two of driving (or even less) in some cases. So the only thing the media can do is broad brush everything since in most cases, they get it right in that sense. There was INDEED snow and wind. Somewhere.

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  35. I like looking at the comments after a storm like this to see the variation around the sound "in real time" as is were. So, thanks to those who give their little personal updates! For my part, we have 6 inches here this morning in Indianola at about 400 ft (currently 26 degrees). No wind as it has built up quite spectacularly on the tree branches. The roads in my neighborhood are covered thickly as well, but often we get quite a bit right here and not so much at slightly lower elevations around Kingston, Poulsbo, etc. So if anyone else in North Kitsap cares to give a status report, I'm curious!

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  36. Traces at Bremerton ferry & airport, traces at Hansville. Narrow zone in between: 6" in Suquamish @ 70', 9" in Poulsbo @ 300'.

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  37. More than a foot of snow here at Snoqualmie Ridge, and still coming down as of 11:45.

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  38. We picked up another inch or so in Bellingham today. Several hours of big lazy flakes - very pretty!

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  39. Thanks, Cliff! Forecasting is tough in this area. I appreciate your blog. Be safe everyone!

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