A Review of Thursday’s Snowstorm and a Forecast for Tonight

A Review of Thursday’s Snowstorm and a Forecast for Tonight

First off, I apologize for getting this out so late – I’ve been extraordinarily busy between the WeatherTogether/WeatherQuack merger and work. Trust me, I wanted nothing more than to give y’all a forecast for the November 3rd snow. But I’ll give you the next best thing – a review, and then a look forward to (well, actually, a look at, since it’s now occurring) the system tonight that will give us another shot at snow. But first – a note about my favorite Pacific Northwest snowstorms.

There are very few things more delightful than a Pacific Northwest snowstorm. Growing up, my first vivid memory of a snowstorm was the massive snowstorm of December 26, 1996, which dumped up to a foot of snow across the Puget Sound lowlands, with another foot occurring on the 29th. The setup was perfect for snow – we had a strong area of arctic, high pressure to the north, and a juicy low pressure system to our south gave us strong northerly winds and copious moisture that fell as snow. The only thing I didn’t remember correctly about it was the date – I thought that all Christmas’ were white by default, and I’ve been disappointed with every Christmas since, with the notable exception of Christmas 2008.

Speaking of 2008, my most memorable weather event by a significant margin (heck, it was a significant life event) was the December 18th, 2008 Puget Sound Convergence Zone thundersnow, which jolted me upright with the most explosive lightning strike I’ve ever experienced in my life. In fact, this storm, and the high school shenanigans that came with it, left such an impression on me that it has its own page. That was also my best forecast in my weather career to date, and it’s unlikely I’ll ever top it.

The November 22, 2010 snowfall was also exceptional for many reasons – it was extremely early in the season for such a widespread and massive snowfall, and it was not predicted whatsoever by models and forecasters (with the exception of the Seattle NWS, who did an excellent job). One of my favorite all-time stats is how our high on November 3, 2010 was 74 degrees and our low on November 24th, only three weeks later, was only 14 degrees.

And of course, who can forget this gem of a video of cars sliding down Capitol Hill.

The last great Seattle snow I remember was during mid-January 2012, which dropped about half a foot at Gasworks Park and made for some spectacular sledding. Unfortunately, I was in Seattle for the Great Portland Thundersnow of 2017, which brought a surprise foot to the Portland metro area that stuck around for a week. Thankfully, my 2008 experience more than made up for that.


What’s the point of me going through all these memorable snowstorms of years past? Well, you can tack on the snowstorm of November 3 to that list. It’s the only memorable snowstorm for me that I actually didn’t experience myself, but the sheer fact that Western Washington saw snow this early in the season is pretty darn impressive. This was the second earliest snowfall on record for Seattle – the earliest dropped 0.4 inches of snow at Sea-Tac airport on October 27, 1972. I don’t even know if I could handle an October snowstorm, so it’s probably for the best that this event held off until the first week of November.

Let’s kick off our overview of the November 3, 2017 snowstorm with some footage from Blaine, Washington. Blaine is your typical border town, with more security cameras and duty-free stores than you can shake a stick at. But during the wee hours of November 3, its weather was anything but typical.

If you turn up the volume, you can hear how windy it was at the time. Blaine, Bellingham, the San Juans, and pretty much everywhere else in the Northern Interior experienced cold, northeasterly winds pouring out of the Fraser River Valley due to high pressure up north and the upper-level low that ended up making landfall near the mouth of the Columbia River.

The Northern Interior commonly sees strong winds when arctic airmasses intrude the region, as these airmasses are associated with much higher surface pressures than typical wintertime pressures in the Western Washington lowlands. Since air flows from high to low pressure, arctic air over inland British Columbia is funneled through the only gap through the B.C. Coastal Range – the Fraser River Valley. This air accelerates at the exit regions of gaps and can deliver some fierce winds to the northern tier of Western Washington.

Sea-level-pressure, 925 hPa (approx 2,500 feet) temperature, and 10-meter winds.
Valid 08:00 am PDT, Fri 03 Nov 2017
Credit: UW Atmospheric Sciences

The above image paints a textbook scenario for snow in Western Washington. You have a low pressure system (albeit a weak one) sliding down from the NNW and making landfall slightly south of Seattle and an arctic air mass just to the north. Because this low pressure system makes landfall just to the south, it provides moisture while still drawing down arctic air through the Fraser River Valley. If this scenario were to occur in December, everybody in Western Washington (and maybe Western Oregon) would see snow.

Here are the snow reports as compiled by the Seattle National Weather Service forecast office.

Public Information Statement
National Weather Service Seattle WA
1056 AM PDT Fri Nov 3 2017

..Updated Snowfall Reports...

Location                     Amount    Time/Date       Elevation (ft.)      

..Washington...

..Clallam County...
3 SW Port Angeles            10.0 in   0700 AM 11/03   0                    
3 WSW Agnew                  5.0 in    0700 AM 11/03   0                    
5 SW Sequim                  4.0 in    0830 AM 11/03   0                    
1 SSE Port Angeles           2.8 in    0700 AM 11/03   0                    
1 SE Sequim                  2.0 in    0700 AM 11/03   0                    
Port Angeles                 1.6 in    0700 AM 11/03   0                    
1 W Port Angeles             1.5 in    0800 AM 11/03   0                    
4 ESE Port Angeles           1.3 in    0700 AM 11/03   0                    

..Jefferson County...
1 SW Chimacum                0.5 in    0700 AM 11/03   0                    
4 W Port Ludlow              0.4 in    0800 AM 11/03   0                    

..King County...
1 NW Snoqualmie Pass         1.4 in    1000 AM 11/03   3100                 
6 WNW Greenwater             1.0 in    0400 AM 11/03   3900                 
Tolt South Fork Reservoir    1.0 in    0815 AM 11/03   2000                 
Eastgate                     0.4 in    0600 AM 11/03   0                    
1 ESE Woodinville            0.4 in    0800 AM 11/03   0                    
1 ESE Woodinville            0.4 in    0925 AM 11/03   0                    
1 NNE Redmond                0.3 in    0800 AM 11/03   0                    
2 WSW Mercer Island          0.2 in    0700 AM 11/03   0                    
2 ENE White Center           0.1 in    0830 AM 11/03   0                    
1 ENE Seattle                0.1 in    0800 AM 11/03   0                    

..Kitsap County...
1 SW Bainbridge Island       0.1 in    0859 AM 11/03   0                    

..Lewis County...
Paradise                     14.0 in   0800 AM 11/03   5130                 
7 S Longmire                 1.0 in    0900 AM 11/03   3770                 

..Pierce County...
Rainier Paradise Ranger Stn  10.0 in   1000 AM 11/03   5427                 
Longmire                     2.0 in    0745 AM 11/03   2762                 
6 W Crystal Mountain         1.3 in    1000 AM 11/03   6410                 
10 WNW Mount Rainier         1.0 in    0900 AM 11/03   3160                 
4 SSW Crystal Mountain       1.0 in    0900 AM 11/03   5240                 

..San Juan County...
8 SE Eastsound               1.3 in    0800 AM 11/03   0                    
4 SSW Friday Harbor          1.0 in    0800 AM 11/03   0                    
5 E Friday Harbor            0.5 in    0605 AM 11/03   0                    
6 ESE Friday Harbor          0.5 in    0700 AM 11/03   0                    

..Skagit County...
18 W Mazama                  2.0 in    0200 AM 11/03   3930                 
5 N Sedro-woolley            1.5 in    0800 AM 11/03   0                    
Concrete Ppl Fish Stn        1.3 in    0640 AM 11/03   195                  
14 SE Diablo                 1.0 in    0900 AM 11/03   4320                 
1 E Mount Vernon             0.5 in    0715 AM 11/03   0                    
Mount Vernon                 0.3 in    0800 AM 11/03   0                    

..Snohomish County...
Brier                        0.2 in    0640 AM 11/03   0                    

..Whatcom County...
Wells Creek Snotel           17.0 in   0800 AM 11/03   4030                 
7 S Mount Baker              14.0 in   0700 AM 11/03   3520                 
12 NNE Hamilton              13.0 in   0800 AM 11/03   3040                 
4 SSE Glacier                12.0 in   0900 AM 11/03   4970                 
12 NW Diablo                 7.0 in    0700 AM 11/03   3630                 
1 E Maple Falls              4.5 in    0700 AM 11/03   0                    
3 SE Bellingham              4.5 in    0700 AM 11/03   0                    
2 SW Bellingham              4.3 in    0700 AM 11/03   0                    
Glacier                      4.1 in    0725 AM 11/03   0                    
2 S Bellingham               4.0 in    0700 AM 11/03   0                    
Mount Baker                  3.3 in    1000 AM 11/03   4210                 
3 NNW Sudden Valley          2.8 in    0700 AM 11/03   0                    
4 ESE Blaine                 2.5 in    0700 AM 11/03   0                    
8 NNE Concrete               2.0 in    0600 AM 11/03   689                  
1 W Lawrence                 2.0 in    0600 AM 11/03   0                    
4 ENE Deming                 1.8 in    0700 AM 11/03   0                    
1 SSE Lawrence               1.7 in    0925 AM 11/03   0                    
2 WNW Ferndale               0.7 in    0700 AM 11/03   0                    
Lynden                       0.3 in    0800 AM 11/03   0                    
Point Roberts                0.3 in    0700 AM 11/03   0                    

And finally, here are some photos from my friends.

A dusting, Little Bear Creek Road in Woodinville, Washington
Credit: Brie Hawkins
A slightly bigger dusting (and it continued to snow for an hour longer), Novelty Hill, Redmond
Credit: Matthew Charchenko
Capitol Hill, Seattle. Dusting on grass.
Credit: Christina Kutz
Coquitlam (suburb of Vancouver, BC). .8 inches (none on roads or sidewalks),
fell between midnight and 6 am on the 3rd.
Credit: Wolf Read
Ferndale, 4.5 inches
Credit: Sandy
A lot of snow, North Bend
Credit: Joe Richards
Sequim, 2 inches
Credit: Ian Barclay
Cheater, Cheater!
Mark Ingalls, reporting barefoot from Donner Summitt, Califronia

Christina also took a video of the snow. As a deep voice in the background (not Christina’s) explains, this was not “typical” snow. Scott Sistek actually wrote a great post on this – the flakes that fell in Seattle proper were as big as 1-2 inches, and the reason was because the above-freezing temperatures partially melted the snowflakes, allowing them to stick together, and the calm winds made sure they didn’t break up before hitting the ground.

That’s enough of the November 3rd snow. Another potential snowstorm is bearing down on us, and it has the potential to bring a few flakes to the Seattle area tonight. This storm is almost a carbon copy of the last one. It is slightly stronger and will take a very similar track. By the way, I hope you’ll forgive me for my exorbitantly liberal use of the word “snowstorm.” This is Seattle we are talking about, after all.

Right now, temperatures range from the low 30s near Bellingham to 40 around the Seattle metro area, with light easterly winds.

Temperatures (black), wind barbs, and wind gusts (red) across the region as of 8:20 11/4/2017
Temperatures (black), wind barbs, and wind gusts (red) across the region as of 8:20 11/4/2017
Credit: NWS Weather and Hazards Data Viewer

The current radar and satellite show the precipitation shield of the storm extending from Cape Flattery all the way down to Pacific City. Compared to this morning’s WRF, the precipitation is a bit ahead of schedule, and I’d expect the heaviest stuff to be over by 1 am for Western Washington and 4 am for Western Oregon.

Radar as of 8:21 pm 11/4/2017
Radar as of 8:21 pm 11/4/2017
Credit: UW Atmospheric Sciences
Infrared Satellite from the GOES-16
Infrared Satellite from the GOES-16
Credit: College of Dupage NEXLAB

As the low passes south of Western Washington in the evening, winds will switch to northerly and frigid air will once again start pouring out of the Fraser River Valley into Western Washington.

Sea-level pressure, 925 hPa temps, and 10 meter winds. Valid 04:00 am PST, Sun 05 Nov 2017.
Sea-level pressure, 925 hPa temps, and 10 meter winds. Valid 04:00 am PST, Sun 05 Nov 2017.
Credit: University of Washington

The heaviest precipitation will be gone at this point, but the models show some residual showers hanging around the Puget Sound area. And with temperatures near or slightly above freezing, you can bet that, if all goes to plan, most places should see a wet sticky snow once more.

24-hour snowfall from 04:00 pm PST, Sat 04 Nov 2017 to 04:00 pm PST, Sun 05 Nov 2017
24-hour snowfall from 04:00 pm PST, Sat 04 Nov 2017 to 04:00 pm PST, Sun 05 Nov 2017
Credit: UW Atmospheric Sciences

The foothills of the Cascades, the southern shoreline of the Strait of Juan de Fuca, the Hood Canal area through SR-8, and areas above 500 feet have the best chance of seeing snow. Like Thursday, this will be a fringe event, and if temperatures are just a degree or two above forecast, the Seattle metro area will just see a rain-snow mix. I’m currently in negotiations with the Weather Gods about places below 50 feet seeing snow – they say it’s not going to happen, but I am a very persuasive fellow. I’ll see if I can get them to budge for ya. 🙂

Thanks so much for reading and have a great night!
Charlie

4 thoughts on “A Review of Thursday’s Snowstorm and a Forecast for Tonight

  1. The most memorable snowstorm of my early childhood in The Dalles was of course late November 1985. Temps as cold as -1F a couple days before Thanksgiving, too….

    Then there was the 1992-93 winter season, where the cold and snow lingered throughout late February and the first few days of March.

    The El Nino season in 1997-98 had a big memorable snowstorm in The Dalles, with about 18 inches and tons of even taller drifts.

    Adulthood memorable snowstorms (besides Dec ’08) included April 20, 2008 in Eugene; March 21, 2012 all over the PNW and November 13, 2014.

    1. Mine would probably be winter of 2003-2004. I lived on McChord AFB near Tacoma and at one point we had 18 inches of snow on the ground. I was nine, but it seemed like we got a couple of different snow storms right around the new year, along with an ice storm that grounded everything to a halt.

      1. I remember January 2004 very well, I forgot to put that one in there. It was a classic overrunning event for us – we got at least 3 inches of snow before it turned to rain. No large discrepancy in elevation (which is good, because we are close to lake level!). Portland got severe freezing rain later on from that storm.

        I have particularly vivid memories from that day walking along Lake Washington with my friend and taking in all the scenery together. Schools were of course closed, and the snow stuck to the roads like glue since they were well below freezing. I remember seeing a guy ski down Madrona Hill outside my friend’s house.

        I was lucky enough to ski down Madrona Hill in 2008… this was taken the evening of December 21, our second big December 2008 snowstorm. I think the snow had stopped falling at the time of this video, but I’m not sure. Little brother alert at 0:20 and dog (ours) alert at 0:56. https://youtu.be/yenpSFiiroI

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