February 13, 2021

The Third Act in the Snow Drama. Plus Freezing Rain Around Portland

 This snow drama was always going to to be in three acts.    The first was a teaser, the second was the main act, and the third will be the transition from snow to rain.

The second act brought substantial snow to the region, particularly from 11 PM Friday through 9 AM this morning.  Here are a few reports from this morning...and keep in mind that many had another inch or two after these reports.

Around 15 inches near Olympia.  12 inches at Ocean shores.    Seattle reaches 8 to 11 inches.

Public Information Statement
National Weather Service Seattle WA
1236 PM PST Sat Feb 13 2021

..SNOWFALL REPORTS...

Location                     Amount    Time/Date       Lat/Lon/Elev (ft.)
Carbonado                    18.0 in   1041 AM 02/13   47.08N/122.05W
9 WNW Alder                  16.0 in   1016 AM 02/13   46.83N/122.47W
3 N Olympia                  15.5 in   1135 AM 02/13   47.09N/122.89W
2 N Tanglewilde-Thomps       15.0 in   1118 AM 02/13   47.08N/122.77W
2 NNE Melbourne              15.0 in   1027 AM 02/13   46.98N/123.61W
Olympia                      14.0 in   0950 AM 02/13   47.04N/122.89W
2 ESE Graham                 14.0 in   1119 AM 02/13   47.05N/122.26W
5 SE Roy                     14.0 in   0932 AM 02/13   46.94N/122.47W
4 SSE Rainier                13.0 in   1042 AM 02/13   46.84N/122.64W
2 SE Tanglewilde-Thomps      13.0 in   0855 AM 02/13   47.03N/122.75W
6 N Tanglewilde-Thomps       12.5 in   1000 AM 02/13   47.14N/122.80W
7 NW Dupont                  12.5 in   1117 AM 02/13   47.18N/122.76W
5 S Vaughn                   12.5 in   0909 AM 02/13   47.28N/122.77W
6 S Port Orchard             12.5 in   1206 PM 02/13   47.45N/122.66W
9 W Alder                    12.0 in   1037 AM 02/13   46.82N/122.48W
1 SSE Lacey                  12.0 in   1001 AM 02/13   47.03N/122.80W
1 NNE Stanwood               12.0 in   1110 AM 02/13   48.26N/122.34W
1 NE Bellevue                12.0 in   0745 AM 02/13   47.62N/122.19W
Ocean Shores                 12.0 in   0930 AM 02/13   46.97N/124.16W

A snowfall map for the last 24 hr from the National Weather Service shows the heaviest amounts between Portland and Olympia (as much as 15-20 inches), with 8-12 inches extending to the central Sound.  Lighter amounts (4-6 inches) over Northwest WA.  

The forecast models were not bad, but overplayed the east-west differences.  I will be looking into this deficiency during the next few weeks (one of my projects is to improve precipitation prediction by numerical models).    

Now about the third act!

Tomorrow morning, a trough of low pressure associated with a weak front will approaching our coast (see surface weather map for 10 AM below, the solid lines indicate pressure, the color shading show low-level temperatures, and I put a dashed oval around the feature of interest).

We will have some residual cold air at low levels and the initial precipitation will be snow, but it will slowly transition to a rain/snow mix during the late morning and afternoon.


This mixed situation is indicated by the forecast precipitation fro 10AM Sunday, with colors indicating snow and gray shades showing rain.


By the evening tomorrow it will be all rain in the lowlands below 1500 ft and snow above.  And Monday, we will see all rain and temperatures zooming up into the lower 40s.

Finally, I should note that Portland and NW Oregon had a significant freezing rain even overnight, as warming temperatures aloft allowed rain above the surface that fell into subfreezing air near the surface.   As a result, the rain became supercooled (still liquid water but below freezing) and then froze on contact with the cold surface.

Portland and vicinity are particularly susceptible to ice storms because of the ready supply of cold air coming out of the Columbia River Gorge.  Seattle has no such cold air source, so ice storms are rare.

Here are some images from Oregon DOT:


The freezing rain weighed down branches and powerlines and resulted in over a quarter-million PGE customers loosing power (that is probably around 3/4 million people). Here is the power outage map this morning.


Enjoy the snow....it is beautiful.   And will probably be the last lowland snow event this season.

______________________________________
Public Radio Station KNKX and Cancel Culture

If you are interested in learning more about public radio station KNKX and cancel culture, check out my new blog/website on the issue: https://knkxcancel.blogspot.com/2021/02/knkx-and-cancel-culture.html

42 comments:

  1. I don't want to disagree with official snow reports, but no way anywhere in ocean shores had 12 inches of snow. It was freezing rain along the coast of grays harbor all night

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    1. Likely a report from a malfunctioning/broken automated system.

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  2. Overall, this snow event was a most enjoyable one...it hits on the weekend, allowing commuters to relax and enjoy their home life!...and the snow is going to be flushed away, mostly, by Monday morning..Great timing--thank you Snow God!

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    1. i agree, i was pleasently surprised to find 4 inches on the ground in bellevue... then, even better, snow showers in the early afternoon brought even more, and because the easterlies died down at that point, it accumulated another 2 or so inches.

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  3. 22 inches so far here in eastern WA. But hey, who cares?

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    1. Eastern Washington huh? No need to get so specific..

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    2. Face it, as far as Seattle and its weather forecasters go, there's no need to be specific.

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  4. 9 inches of snow in renton although the wind blew it around so much that depending on where you measure you might find as little as 4" or as much as 13". The NOAA forecast was absymal they were calling for 1 to 3 inches until right before the storm at which point they forecasted 2 to 6 inches. I get that snowstorm forecasts often bust and they wanted to be alittle extra cautious but when 80% of the esembles are going for a big storm shouldn't they error on the side of caution and over-predict? They got the first storm right but with so many models predicting big totals it didn't seem like all 3 storms would bust.

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    1. 7 inches in wind-shadowed locations on our property east of Duvall. But, yes, in those areas where the wind was blowing, we either have an inch or 13-14 inches of snow. The event reminded me of the February 10th, 2019 snow event, but without the pre-existing snow from earlier.

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    2. Storm1, I felt the exact same way about the model runs shown here vs. the NOAA forecast and the forecast made by the local media. It was pretty clear that all of the model runs Cliff shared were giving a really large probability of a pretty major storm. Instead when I turned on the news they were telling me that my area (3 miles west of downtown Gig Harbor) was expecting 4”-8”. Based on the data on this blog I surmised we’d most likely be in the range of 10”-16” and after the snow stopped at 1pm yesterday I measured 15” on our table outside. I’m not going to complain though as I love snow. I just don’t understand why the NOAA & local media outlets were so gung ho on downplaying this event when so much data clearly showed otherwise. Now I hope all the forecasts are wrong and we stay cold for the next week!

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  5. Euro model was very, very close. Kudos to them. NOAA doesn't know-a

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  6. Ocean Shores got maybe an inch of snow and then ice, not sure who reported the 12 inch amount but it is laughably wrong.

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  7. How about the effect on the passes on Sunday and Monday?

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    Replies
    1. Calling for 2 feet from Sunday night through early Tuesday morning. Snow level 2k feet. Riding should stay excellent.

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  8. Seven and a half inches here on the Bothell-Mill Creek line, ending at 8:50 Saturday.

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  9. That light blue dot east of tacoma is right near me—between Puyallup and sumner. We didn’t even crack 3 inches, while people just a few miles away had 3 or 4 times as much snow as we did. Extremely strange, and I would love theories as to why.

    I thought it could be the east wind, but places north of us still got walloped too.

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  10. Got just over 12” at my place on the North end of Vashon Island. Not too shabby!

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  11. About 7-8" of measurable snow here in Pacific, WA. YAY! I got my snow!

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  12. I am worried about the snow making the branches break and having power outages for the next few days.

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    1. The trees will be fine. They are really only in danger when its a very heavy, wet snow coming down in a torrent or a thick coating of ice develops from sleet and freezing rain. All around, freezing rain is THE WORST of winter precipitation.

      Once it has stopped snowing and it warms up, the darker hues of the bark/needles will cause the snow in contact with it to melt leading to snow sliding off in clumps. The weighted, downward drooping branches are already like a slide and the snow at higher branches will knock loose the snow on lowers as its falls.

      Trees have been in the snow business much longer than we have!

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    2. Yes i agree, exept I was lucky enough to see a branch snap in half in crossroads, Bellevue today! pretty cool sight

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  13. Not sure about the 4-6" over Northwest Wa. We had a compacted 8" at 5 pm yesterday in S Bellingham with the snow continuing to fall.

    Been snowing lightly again since around 7 am this morning with 29 degrees.

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  14. In Tacoma down by Titlow Park we had almost 9" by the time it stopped snowing Saturday afternoon

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  15. As I wrote yesterday, at least out where I live, I got about 10" all told. It did start snowing again this morning just before 7AM but seems to have mostly stopped now at 9:05AM, but still very cloudy though.

    It was not easy walking in the white stuff yesterday afternoon but it sure was pretty though.

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  16. After a fairly light snowfall yesterday in Maple Valley (3-4") it's been snowing steadily since daybreak. Easterly flow is continuing with temps holding at 28. I agree with the NWS forecast discussion- the cold air will be slow to scour out and I think we are going to have a messy, icy transition into warmer weather. It ain't over yet....

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  17. It's currently 28 degrees and snowing like crazy in east Woodinville

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  18. My mom moved us to the outskirts of Portland, OR, beginning around the time of the Columbus Day storm. I remember winters where the branches were encased in ice and the snow drifts were so high that the tops of cars were covered. It was fun to be a teen there. We all lived for snow days.

    I moved to Southern CA as an adult to make good money at law firms, but I hated it there. Way too 'cement city' for one raised in the PNW. My beloved hubby and I took a trip to Seattle one year and ended up in Lynnwood. So we packed it up and moved here.

    I miss him terribly, may he rest in peace, but I'm so glad he got to experience many years up here. He loved it. When we moved here, I expected weather like Portland, but it's not. The snow levels are actually less and there's no smog to speak of. I love Washington so very much. Oregon's lovely, too. I just like it better here.

    It's been snowing all morning this fine Valentine's Day. I expect it to continue as snow until tomorrow, as the flakes are still small, but we shall see. I just hope I'm not snowed in for two weeks. My place takes forever to thaw out. When all my neighbors are free and clear, I still have tons of snow at my place.

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  19. This event is another reminder that not all models perform as well. When I have to plan for weather and it comes down to trusting the EURO or UW's model (pushed in this blog), I rarely have gone wrong in trusting the EURO. My 1" of snow for UW translated to over 7" as shown in the EURO (I measured 7.5" before the latest batch). Such a shame our modeling doesn't do better...

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  20. still snowing moderately in bellevue, 8.5 inches on the porch, but its very close to above freezing, probably will start raining in the next couple of hours. It was fun while it lasted!

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  21. Sunday almost 1 pm: Still snowing, about 15" in our Seattle neighborhood (on a ridge above the lake) and less in the adjacent neighborhood just one mile north.

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  22. 12 inches of snow in my yard in the North Seattle Maple Leaf Alps!

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  23. Yes! Warned my friends several days ago. I told them the experts at UW were saying up to a foot of snow in Seattle. Based on fancy models from around the world. Now, 12 inches of powder snow at Volunteer Park on Capitol Hill, Seattle! They are believers again! Had to redeem myself after the smoke plume model debacle late last summer. Phew.

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  24. 10+ inches on the North end of Camano Island.
    Sunday at 4:30 PM? 36°F and snowing lightly.
    Waiting for the rain to wash it all away...

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  25. Dear Dr. Mass,
    I would like to see some discussion on a couple of matters. Why is the ECMWF so much more accurate that GFS and why does the NWS lean on the one that doesn't work as well?

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  26. The three day three act snowstorm could be called the Lincoln's Birthday Chinese New Year Valentines Eve Valentines Day snowstorm which would add one more storm to the list of Seattle storms that occurred on holidays and were named for the holidays that they occurred on. It would also be the first on a list of storms that continued through more than one holiday. If the snowstorm would somehow have continued until Wednesday it could have been called the Lincoln's Birthday Chinese New Year Valentines Eve Valentines Day Presidents Day Fat Tuesday Ash Wednesday snowstorm!

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  27. The eastern winds in North Bend were immense on Friday night and Saturday, Cliff was spot on with his prediction that these winds would result in drying out the precipitation. The snow was blowing sideways but it was falling in a sugary like consistency that did not stay to the surface before being blown away. A great side effect was that you could see how the wind gusts were creating vortices as air moved over open areas. Cliff, it would be great if you could do a podcast on the East-West pressure gradients and why the air seems to funnel along through North bend yet driving a little farther north it's almost calm.

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  28. The three day three act snowstorm could be called the Lincoln's Birthday Chinese New Year Valentines Eve Valentines Day snowstorm which would add one more storm to the list of Seattle storms that occurred on holidays and were named for the holiday that they occurred on. It would also be the first on a list of storms that continued through more than one holiday. If the snowstorm would have somehow continued until Wednesday it could have been called the Lincoln's Birthday Chinese New Year Valentines Eve Valentines Day Presidents Day Fat Tuesday Ash Wednesday storm!

    ReplyDelete
  29. Over a foot here on Camano Island. The higher elevations seemed to get more snow than the lower (which is not unusual, but some people recorded 6 - 10" while I got a lot more). It was wonderful being snowed in.

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  30. I had 13" of snow accumulated on my driveway in Redmond Ridge East before I started shoveling around noon. Not quite as bad as we had 2 years ago but still plenty...

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  31. Does anyone know how much freezing rain fell in foothill towns like Index, North Bend and Enumclaw? Last night it was 33 and raining in Renton a few patches of black ice but not quite cold enough for a big ice storm. I noticed than many of the foothill towns were still 25 to 30 and was wondering if they got more snow or freezing rain.

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  32. 12-14” of snow here in Columbia City, three miles south of downtown Seattle. It seemed like once it started snowing on Friday, it didn’t stop until 3pm on Sunday. Amazing.

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Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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