February Weather in the Pacific Northwest

[Dave]

TWC is calling for a 41/13 spread here on Monday. Could kill a few bugs.

[seattleweatherguy]

URGENT - WINTER WEATHER MESSAGE

National Weather Service Seattle WA

1132 AM PST Sat Feb 17 2018

 

WAZ504-506-507-509>512-516-517-556-180600-

/O.NEW.KSEW.WW.Y.0014.180218T0600Z-180218T1700Z/

Southwest Interior-Western Skagit County-Everett and Vicinity-

Tacoma Area-Admiralty Inlet Area-Hood Canal Area-

Lower Chehalis Valley Area-North Coast-Central Coast-

Bellevue and Vicinity-

Including Lacey, Olympia, Tumwater, Yelm, Tenino, Grand Mound,

Rochester, Littlerock, Centralia, Napavine, Toledo, Burlington,

Mount Vernon, Sedro-Woolley, La Conner, Conway, Everett,

Lynnwood, Marysville, Stanwood, Tacoma, Fife, Steilacoom, DuPont,

Roy, Puyallup, Spanaway, Graham, Fox Island, Vaughn,

Port Townsend, Oak Harbor, Coupeville, Freeland, Langley,

Shelton, Seabeck, Belfair, Leland, Brinnon, Hoodsport, Montesano,

Elma, McCleary, Matlock, Beaver, Clearwater, Forks, Neah Bay,

Ozette, Queets, Aberdeen, Hoquiam, Westport, Ocean Shores,

Humptulips, Bellevue, Bothell, Kenmore, Mill Creek, Clearview,

Kirkland, Newcastle, Redmond, Sammamish, and Issaquah

1132 AM PST Sat Feb 17 2018

 

...WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO

9 AM PST SUNDAY...

 

* WHAT...Snow expected. Plan on slippery road conditions. Total

snow accumulations of up to two inches are expected.

 

* WHERE...Anacortes, Mount Vernon, Everett, Bellevue, Puyallup,

Chehalis, Quilcene, Matlock, Humptulips, and Forks.

 

* WHEN...From 10 PM this evening to 9 AM PST Sunday.

 

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at

times.

 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

 

A Winter Weather Advisory for snow means periods of snow will

cause primarily travel difficulties. Be prepared for snow covered

roads and limited visibilities, and use caution while driving.

The latest road conditions for the state you are calling from can

be obtained by calling 5 1 1.

 

$$

[Front Ranger]

That doesn't matter a lot with such an anomalous pattern though.

 

True to a certain extent. Although I think you'd generally need 850s a degree or two colder to get the same results a couple weeks from now.

[Front Ranger]

URGENT - WINTER WEATHER MESSAGE

National Weather Service Seattle WA

1132 AM PST Sat Feb 17 2018

 

WAZ504-506-507-509>512-516-517-556-180600-

/O.NEW.KSEW.WW.Y.0014.180218T0600Z-180218T1700Z/

Southwest Interior-Western Skagit County-Everett and Vicinity-

Tacoma Area-Admiralty Inlet Area-Hood Canal Area-

Lower Chehalis Valley Area-North Coast-Central Coast-

Bellevue and Vicinity-

Including Lacey, Olympia, Tumwater, Yelm, Tenino, Grand Mound,

Rochester, Littlerock, Centralia, Napavine, Toledo, Burlington,

Mount Vernon, Sedro-Woolley, La Conner, Conway, Everett,

Lynnwood, Marysville, Stanwood, Tacoma, Fife, Steilacoom, DuPont,

Roy, Puyallup, Spanaway, Graham, Fox Island, Vaughn,

Port Townsend, Oak Harbor, Coupeville, Freeland, Langley,

Shelton, Seabeck, Belfair, Leland, Brinnon, Hoodsport, Montesano,

Elma, McCleary, Matlock, Beaver, Clearwater, Forks, Neah Bay,

Ozette, Queets, Aberdeen, Hoquiam, Westport, Ocean Shores,

Humptulips, Bellevue, Bothell, Kenmore, Mill Creek, Clearview,

Kirkland, Newcastle, Redmond, Sammamish, and Issaquah

1132 AM PST Sat Feb 17 2018

 

...WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO

9 AM PST SUNDAY...

 

* WHAT...Snow expected. Plan on slippery road conditions. Total

snow accumulations of up to two inches are expected.

 

* WHERE...Anacortes, Mount Vernon, Everett, Bellevue, Puyallup,

Chehalis, Quilcene, Matlock, Humptulips, and Forks.

 

* WHEN...From 10 PM this evening to 9 AM PST Sunday.

 

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at

times.

 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

 

A Winter Weather Advisory for snow means periods of snow will

cause primarily travel difficulties. Be prepared for snow covered

roads and limited visibilities, and use caution while driving.

The latest road conditions for the state you are calling from can

be obtained by calling 5 1 1.

 

$$

 

Trigger pulled!!!

 

1-4" for EPSL.

[Front Ranger]

This is looking like the second winter in a row where SEA and PDX could handily beat DCA for snowfall. Always nice to see.

[MR.SNOWMIZER]

Except seattle Bremerton area. Seattle shafted again.

[VancouverIslandSouth]

Very dynamic day today, it was pouring in the morning then cleared up with blue sky now we're getting hit with heavy windswept rain.

[Farmboy]

URGENT - WINTER WEATHER MESSAGE

National Weather Service Seattle WA

1132 AM PST Sat Feb 17 2018

 

WAZ504-506-507-509>512-516-517-556-180600-

/O.NEW.KSEW.WW.Y.0014.180218T0600Z-180218T1700Z/

Southwest Interior-Western Skagit County-Everett and Vicinity-

Tacoma Area-Admiralty Inlet Area-Hood Canal Area-

Lower Chehalis Valley Area-North Coast-Central Coast-

Bellevue and Vicinity-

Including Lacey, Olympia, Tumwater, Yelm, Tenino, Grand Mound,

Rochester, Littlerock, Centralia, Napavine, Toledo, Burlington,

Mount Vernon, Sedro-Woolley, La Conner, Conway, Everett,

Lynnwood, Marysville, Stanwood, Tacoma, Fife, Steilacoom, DuPont,

Roy, Puyallup, Spanaway, Graham, Fox Island, Vaughn,

Port Townsend, Oak Harbor, Coupeville, Freeland, Langley,

Shelton, Seabeck, Belfair, Leland, Brinnon, Hoodsport, Montesano,

Elma, McCleary, Matlock, Beaver, Clearwater, Forks, Neah Bay,

Ozette, Queets, Aberdeen, Hoquiam, Westport, Ocean Shores,

Humptulips, Bellevue, Bothell, Kenmore, Mill Creek, Clearview,

Kirkland, Newcastle, Redmond, Sammamish, and Issaquah

1132 AM PST Sat Feb 17 2018

 

...WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO

9 AM PST SUNDAY...

 

* WHAT...Snow expected. Plan on slippery road conditions. Total

snow accumulations of up to two inches are expected.

 

* WHERE...Anacortes, Mount Vernon, Everett, Bellevue, Puyallup,

Chehalis, Quilcene, Matlock, Humptulips, and Forks.

 

* WHEN...From 10 PM this evening to 9 AM PST Sunday.

 

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at

times.

 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

 

A Winter Weather Advisory for snow means periods of snow will

cause primarily travel difficulties. Be prepared for snow covered

roads and limited visibilities, and use caution while driving.

The latest road conditions for the state you are calling from can

be obtained by calling 5 1 1.

 

$$

No mention of Auburn, Kent, Renton, Maple Valley. #DrySlot

[HighlandExperience]

I have a hard time believing that Fife and Puyallup will get more snow than Issaquah and Maple Valley area.  We better not get dry slotted. 

[VancouverIslandSouth]

Impressive contrasts in the Fraser Valley today, Abbotsford is sitting at 45F while nearby Agassiz is at 32F.

[Front Ranger]

Very dynamic day today, it was pouring in the morning then cleared up with blue sky now we're getting hit with heavy windswept rain.

 

You can see it in the Space Needle Cam, too. Whitecaps, sunbreaks, and windswept clouds.

 

[Front Ranger]

No mention of Auburn, Kent, Renton, Maple Valley. #DrySlot

 

Maple Valley and Covington are both mentioned in the 1-4" advisory for the EPSL.

[Jesse]

The old PSU panels suggest -25 to -30C in 1990

 

72DBCDB6-357D-4C03-BCBC-B8E68E5825CE.png

 

I see. Then again it appears that the -10C line was hung up over the border there. This time its expected to be down around Eugene at its farthest south.

[VancouverIslandSouth]

Looks pretty snowy in Hope today. Always nice to see snow falling in the upstream outflow regions.

 

http://images.drivebc.ca/bchighwaycam/pub/cameras/241.jpg

[Winterdog]

Wind coming from NW here now and rain has stopped.

[luminen]

To my surprise there was a dusting of snow on cars and grass here this morning but it quickly changed over to a soaking rain. Looks like it's stopped raining now though.

[Perturbed Member]

GEPS

 

 

 

There are at least a few members in there that keep that Wednesday low offshore to the west like the Euro/ICON/NAVGEM. 

[MR.SNOWMIZER]

The 18z nam still wants to bring the low down over puget sound at about 1000mb. Pretty hard to think Seattle would still get dry slotted if this happened.

[MR.SNOWMIZER]

18z nam looking pretty good for snow in central sound.

[TigerWoodsLibido]

51 still with winds getting even more blustery.  No more hole in the clouds from the shadow.

[Blizzard777]

Looks like my weather station has reached its high today, time to head alt rout. Barometer looks to have bottomed out as well. 29.64 on the barometer

[bainbridgekid]

In all likelihood, the central Puget Sound region will probably get dry slotted at the start due to the NNW flow (similar to today).

 

That being said, once the low drops south of the Olympics and the modified Arctic boundary slides south down the Sound, we will get our share.

Agreed. There are almost always 4-8 hours of near panicked frustration waiting for the snow to drop South and fill into the Central Sound in these setups.

 

The time to shine for the Central Sound will likely be 8 AM to Noon or so IMO.

[Front Ranger]

I see. Then again it appears that the -10C line was hung up over the border there. This time its expected to be down around Eugene at its farthest south.

 

Yeah, there were several different pushes of cold in Feb 1990 (much as it appears there will be in 2018). A couple of them did push the -10C line much further south, but the final one on that map was more of a low level push south of the border.

 

Way too soon to directly compare the two periods of events, of course. But at this point, it appears to me that 2018 will stack up fairly favorably to 1990 for the PNW overall, especially since this one is beginning right around when that one was ending.

[Front Ranger]

Agreed. There are almost always 4-8 hours of near panicked frustration waiting for the snow to drop South and fill into the Central Sound in these setups.

 

The time to shine for the Central Sound will likely be 6 AM to Noon or so IMO.

 

I wouldn't be surprised if it ends up even being a little later, considering how those surface lows often seem to get hung up around the Olympics.

 

But this does appear to be a more dynamic modified Arctic front than we've seen in awhile, so who knows...maybe things will progress faster south.

[ShawniganLake]

18Z NAM

 

[MossMan]

Temp went from 46 to 42 in the past hour.

[Front Ranger]

18z nam looking pretty good for snow in central sound.

 

Hi-res 3km NAM looks very anemic for pretty much everyone between BLI and OLM, unfortunately. Shows very little snow for most places within 20 mi of the water. Can't imagine that scenario actually happening.

[HighlandExperience]

Hi-res 3km NAM looks very anemic for pretty much everyone between BLI and OLM, unfortunately. Shows very little snow for most places within 20 mi of the water. Can't imagine that scenario actually happening.

Looks worse than the WRF and EURO.

[MR.SNOWMIZER]

Hi-res 3km NAM looks very anemic for pretty much everyone between BLI and OLM, unfortunately. Shows very little snow for most places within 20 mi of the water. Can't imagine that scenario actually happening.

I think whats happening is none of the models are seing much if any convergence action. And maybe there wont be.

[HighlandExperience]

[MossMan]

[MR.SNOWMIZER]

What was the pressure of the low in nov 2010?

[Front Ranger]

I think whats happening is none of the models are seing much if any convergence action. And maybe there wont be.

 

It's just a situation they all struggle with. Tomorrow won't be widespread, heavy snowfall, but history tells us a few places will do really well.

[jaya]

Low level cold not looking very impressive upstream this morning. Currently 19F in Prince George. With the 1990 outbreak it dropped to the mid -30’s up there.

Cold here west of the Cascades and Canadian Coastal Range comes more from aloft than in the low levels. So for snow, not so much of an issue. For extreme cold, you have a point. We won't see temperatures in the single digits F around here with the air mass coming in. 

[MossMan]

Power now flickering.

[Jesse]

Cold here west of the Cascades and Canadian Coastal Range comes more from aloft than in the low levels. So for snow, not so much of an issue. For extreme cold, you have a point. We won't see temperatures in the single digits F around here with the air mass coming in.

He was talking about the BC interior. Single digits would basically be unheard of for the I-5 corridor this late in the season, even if the cold air were moving in straight from the NE.

[ShawniganLake]

Power now flickering.

Half of Shawnigan is without power. Looks like 6000 or so on southern Vancouver Island.

[jaya]

NWS is all federal employees. No one probably paying attention on a holiday weekend. 

I cry Fake News! here.  We work 24 x 7 and don't get holidays off, plus rotating shifts that most people would not bother with.

[Canadian guy]

Jaya are your thoughts still the same for tonight and tomorrow?

[wxmet]

In all likelihood, the central Puget Sound region will probably get dry slotted at the start due to the NNW flow (similar to today).

 

That being said, once the low drops south of the Olympics and the modified Arctic boundary slides south down the Sound, we will get our share.

 

By the time the low slides south, there may not be enough moisture available. Looking at the current radar, I would not be surprised if tomorrow ends up being similar, only leading to a dusting or so of snow. Still, where the bands will setup will be difficult to pinpoint outside of watching the radar tomorrow. This Arctic boundary is not particularly impressive with the gradient being driven mainly by the high to the north and not a strong surface low. The best 700mb dynamics are to the east over eastern Washington. Things over western Washington look more orographically enhanced.