February Weather in the Pacific Northwest

[Esquimalt]

The Clown Range on the GFS is a joke.  Widespread snow throughout the lowlands.  If only.... 

[wx_statman]

The 3km NAM has a crazy strong cutoff. Washington County gets 4-7 inches. Clark County basically gets nothing. 

 

If I remember right, the 3km NAM overdid the snowfall amounts in the bullseye for last night, but nailed where the snow would fall/not fall (i.e. Portland vs Salem). The 12km had more accurate amounts. 

[TT-SEA]

I disagree. There will be shadowing at some point with the low north of the area and the flow coming on shore. You are again confusing the track of the low with the actual flow as the low slides south. Precip is happening because at that point the flow is on the windward side of the Olympics as the slow slides to the south but even with that the available moisture is departing the area.

 

No.    There will not be shadowing.   

 

Here is 4 p.m. today per the 00Z... precip is not even here yet.   This is not shadowing.   When the precip comes through the flow is offshore and there is drying in the Seattle area.   

 

 

[wxmet]

No. There will not be shadowing.

 

Here is 4 p.m. today per the 00Z... precip is not even here yet. This is not shadowing. When the precip comes through the flow is offshore and there is drying in the Seattle area.

 

 

We can agree to disagree and move on.

[TT-SEA]

It does not matter if things are ahead of schedule if the low takes the same predicted track.   Timing might move up but the dynamics will be the same as the event unfolds.   

[wx_statman]

We just pulled off a sunny, snowcovered morning with a hard freeze on 2/21. Like it ain't no thing. Latest I've ever seen this happen in 25 years living here. 

[TT-SEA]

We just pulled off a sunny, snowcovered morning with a hard freeze on 2/21. Like it ain't no thing. Latest I've ever seen this happen in 25 years living here. 

 

Nice! 

[ShawniganLake]

The Clown Range on the GFS is a joke. Widespread snow throughout the lowlands. If only....

Wouldn’t surprise me to see it stay chilly through the first week of March. It likes to snow up here that time of year.

[Guest Dome Buster]

I don't see this low developing where the models are saying. Too much of a NNW flow in the upper levels. Looks like another mouth of the Columbia special to me

[TT-SEA]

We can agree to disagree and move on.

 

Well... its not really an opinion.    As the precip moves through and the low passes to the west... the flow turns offshore in King County with a drying effect.    Areas closer to the Olympics very often do better than areas near the Cascades in these situations.   Its not a shadowing situation in Seattle.   

[wx_statman]

Record low?! Wow some major low hanging fruit. Score one for the 21st Century!

 

To be fair, 24 (and we may have dropped lower) is pretty impressive for PDX by this point in the winter. 

[Guest Dome Buster]

Well... its not really an opinion. As the precip moves through and the low passes to the west... the flow turns offshore in King County with a drying effect. Areas closer to the Olympics very often do better than areas near the Cascades in these situations. Its not a shadowing situation in Seattle.

I agree with that. Living in bothell/Everett areas for 14 years, this pattern just sucks for the north/central sound. Need the low to come in around hoquiam to induce onshore flow, i.e. PSCZ. Really the only hope up there in this pattern.

[MR.SNOWMIZER]

No update yet from NWS Seattle, Bet there waiting on Euro.

[wx_statman]

Seems like pretty good consensus for at least 1-2" across most of W. Oregon. 

 

Also the daily climate report says PDX had 4.2" yesterday. 

 

Very impressive. Heaviest daily snowfall since March 1951 for this late. 

[Guest Dome Buster]

No update yet from NWS Seattle, Bet there waiting on Euro.

Ya. Portland only updated marine and aviation. I would assume a 10:30 or so update from both.

[MossMan]

Sun is quickly warming us up... need more cloud cover to come through to keep a lid on temps.

Very cloudy up here, probably moving your way!

[MR.SNOWMIZER]

Sun is quickly warming us up... need more cloud cover to come through to keep a lid on temps.

Temps wont be a issue. Upper levels are cold dew points are low. Snow would fall out of the sky today if it was 38.

[ShawniganLake]

I don't see this low developing where the models are saying. Too much of a NNW flow in the upper levels. Looks like another mouth of the Columbia special to me

isn’t that what they are showing. Landfall near the mouth of the Columbia

[Jesse]

Unbelievably gorgeous morning. I’ve basically just been outside the last 2-3 hours. The thick snow coating the trees and everything else is perfection.

 

Dropped to 19 here right after sunrise. And still hanging in the mid 20s with increasing clouds. Feels like the dead of winter out there, despite being just a week from March. Fun stuff!

[seattleweatherguy]

noaa says  this for bothell for tonight for what its worth

 

A 50 percent chance of snow. Cloudy, then gradually becoming partly cloudy, with a low around 27. Northeast wind around 6 mph becoming calm in the evening. New snow accumulation of less than one inch possible.

 

High of only 35 very impressive.

[ShawniganLake]

Temps wont be a issue. Upper levels are cold dew points are low. Snow would fall out of the sky today if it was 38.

I agree. Tough to see much accumulation with light precip and temps above freezing though.

[Jesse]

I’ve gotta catch up on all the posts/models at some point today. Just crazy that we could be looking at another snowfall and reinforcing shot of cold tonight/tomorrow morning.

[TigerWoodsLibido]

34 with beautiful sunshine on my green grass. Maybe we will get lucky tonight?

[AlTahoe]

I’m at 150” of snowfall now on the season and I can say I still appreciate every snowfall like it’s the first of the year. Never gets old. Once a snow lover, always a snow lover. I highly recommend anyone who loves snow, move to a snowy location and stop torturing yourself!

I spent 12 years getting into a position in IT where I could work remotely from anywhere to escape the Bay Area's lame weather. Bought a house in Lake Tahoe so I could finally live in one of the snowiest cities with a decent size population in the Country. Then of course we decide to have a 1-500 year snow drought. FML

It's like we have lost winter entirely from Jan 2012 onward. It only snows in March and April as the coldest winter months have been bone dry (outside of last year). This year I am currently at 14" of snow for the winter. Average is around 150-190". 6 of our last 7 winters have been below 100" and 5 out of 7 have been below 50". Our record winter is 535" at lake level. 2010-2011 we had 330"

I am considering a move to Bozeman in the next 1-3 years if this snow drought doesn't break.

[wxmet]

Well... its not really an opinion.    As the precip moves through and the low passes to the west... the flow turns offshore in King County with a drying effect.    Areas closer to the Olympics very often do better than areas near the Cascades in these situations.   Its not a shadowing situation in Seattle.   

 

 

What does the flow turn from onshore to offshore  ? Give me wind directions if you are going to be adamant about trying to make a point. You're right it's not an opinion so let's look more closely. Here is the NAM 12z 12km showing onshore flow against the windward (west) side of the Olympics. Winds from the west against the west side of the Olympics. 

 

 

The radar imagery at the corresponding time (and there after) show a textbook rain showing event. Dry air over the lowlands due to descending air over after the flow crosses the Olympics. So why does it start precipitating after this? The flow turns from west to south then finally east (offshore when the low is to the south). During the time when the flow is coming from a more southerly, direction this allow moisture transport to get into the Pugent Sound where the flow parallel to its structure and not obstructed by the Olympics.

 

Rain shadow:

 

[wxmet]

The frame after that showing the rain shadowing continuing but lessing as the flow veers:

 

[TT-SEA]

What does the flow turn from onshore to offshore  ? Give me wind directions if you are going to be adamant about trying to make a point. You're right it's not an opinion so let's look more closely. Here is the NAM 12z 12km showing onshore flow against the windward (west) side of the Olympics. Winds from the west against the west side of the Olympics. 

 

 

 

The radar imagery at the corresponding time (and there after) show a textbook rain showing event. Dry air over the lowlands due to descending air over after the flow crosses the Olympics. So why does it start precipitating after this? The flow turns from west to south then finally east (offshore when the low is to the south). During the time when the flow is coming from a more southerly, direction this allow moisture transport to get into the Pugent Sound where the flow parallel to its structure and not obstructed by the Olympics.

 

Rain shadow:

 

 

The dry slot over Seattle is the result of drier easterly flow downsloping from the Cascades.    Are you really using the NAM over the detailed ECMWF surface maps?

 

As the precip arrives and the low passes to the west... offshore flow kicks in.    

 

Not every hole in the precip over Seattle is the result of shadowing from the Olympics... sometimes its related to the gap in the Cascades through Snoqulamie Pass.  That is when its also dry in North Bend as it will likely be this evening.

[BLI snowman]

We just pulled off a sunny, snowcovered morning with a hard freeze on 2/21. Like it ain't no thing. Latest I've ever seen this happen in 25 years living here. 

 

Late winter can still be nice historically. Encouraging to see our climate remember that!

[wxmet]

Whether the shadowing is from the east or the west the Central Sound is still shadowed and no amount of bickering to see who's right will change that, unfortunately.

Glad I have some agreement.

[TT-SEA]

Glad I have some agreement.

 

OK... if you are saying shadowing from the Cascades then I sort of agree!   Although its not really shadowing at all when the precip is moving south along the coast.   Its dry easterly flow which probably means lots of virga.

 

You said flow was onshore with precip and the Olympics were doing their usual shadowing work.    This is the opposite situation. 

[TigerWoodsLibido]

Nice, big college basketball fan?

Bigtime. Went to 3 games this season so far.

[wxmet]

OK... if you are saying shadowing from the Cascades then I agree!

 

You said flow was onshore with precip and the Olympics were doing their usual shadowing work. This is the opposite situation.

Shadowing can occur from both the east and the west as hawk mentioned. Why you are still arguing about this at this point is beyond me.

[MR.SNOWMIZER]

Whether the shadowing is from the east or the west the Central Sound is still shadowed and no amount of bickering to see who's right will change that, unfortunately.

Nobody's right if everybody;s wrong..

[MR.SNOWMIZER]

12z euro maps Tim. Please.

[TT-SEA]

Shadowing can occur from both the east and the west as hawk mentioned. Why you are still arguing about this at this point is beyond me.

 

You did not say that.   You were pointing to onshore flow on the NAM which means shadowing from the west and the Olympics.    You need offshore flow for shadowing for the Cascades.   

 

I am bored... still waiting for everyone to wake up here. 

[wx_statman]

Late winter can still be nice historically. Encouraging to see our climate remember that!

 

For sure. Now for a March 1906 repeat...

[TT-SEA]

12z euro maps Tim. Please.

 

Total snow through 10 a.m. tomorrow... this is an improvement for all of King County compared to the 00Z run.

 

[TT-SEA]

Hey, look, no shadow!

 

Might be enough precip to overcome offshore flow... maybe a widespread 1-2 inches over the entire Seattle area which would be quite nice for everyone! 

[wxmet]

You did not say that. You were pointing to onshore flow on the NAM which means shadowing from the west and the Olympics. You need offshore flow for shadowing for the Cascades.

 

I am bored... still waiting for everyone to wake up here.

I’ve have mentioned this before several days ago about the location that Seattle is in between two mountain ranges makes it difficult for it to snow which is due to shadowing from either side. There will be shadowing from the Olympics today and there is no amount of you needing to have the last word (or your lack of knowledge) changing that ). I stand by everything that I have said.

[wx_statman]

Second surprise 23 at PDX of the season, both with snowcover. If only January hadn't been such a turd...