PNW December 2022 - Part II

[VancouverIslandSouth]

Just now, TT-SEA said:

This is ECMWF snow from right now through 4 p.m. tomorrow... this excludes the snow that has already fallen.     That bullseye east of the Olympics is still there.

It's been showing that for awhile now, but I don't quite understand the effect that's causing it. Maybe upslope? But then I would expect it to be more widespread along the north of the Olympics. Perhaps some super localized convergence?

[Ice_is_Everywhere]

Do Wednesday and Thursday still look cold?

[Gummy]

3 minutes ago, MillCreekMike said:

Wow just got home. ZERO snow here. Not even anything coming down even though there’s echoes over me. Right when I passed the Highway 9 exit on Highway 2 the snow just vanished. That was so depressing. Maybe north Everett wasn’t the best spot to move. Been burned twice in a row

Might get burned again if the ECMWF keeps trending that low north on Tuesday. The EPS looks better, just have to hope it is off a bit on the placement.

[TT-SEA]

Snowing hard in North Bend...

[KingstonWX]

Finally getting "real" snow here now, and starting to stick. 33 with a DP of 31.

[TT-SEA]

1 minute ago, Ice_is_Everywhere said:

Do Wednesday and Thursday still look cold?

Highs Wednesday.   18Z run ends at 90 hours.

[KingstonWX]

It's that time during a snow event when the AFD is running late and I spent a weird amount of time imagining what's going on inside NWS Seattle. 

[Kolk1604]

I just noticed WB has a model update schedule and you can filter it to local time. That's pretty cool!

1/2 hour until the 18z EPS saves us all and puts this outlier EMCWF to bed! 

[MikeInEverett]

Weenie mode has been activated for me it seems  

[SnowWillarrive]

Moderate snow from tiger summit all the way into Maple Valley. From the looks of the Euro tonight almost looks like the main event. Kinda lame 

[Meatyorologist]

10 minutes ago, TT-SEA said:

3 inches isn't bad... better than what it shows for the Seattle area.

Tell that to her.. 

[Meatyorologist]

Update...

Looks like this is very shallow stuff since KATX is missing a bit of it. Filling in from the west regardless, similar to what the GFS and RGEM depicted. Could last into the early morning.

[bishbish777]

Wow 18Z Euro with the complete rug pull for Seattle metro. Hard to believe we could get through this with no snow in Seattle but that's definitely on the table now. 

[MR.SNOWMIZER]

We will be running out of out stream of moisture pretty quickly it looks like. 

[Meatyorologist]

Been a very long while since North Seattle was 'zoned in an Arctic frontal event. Last December we got hit pretty good but it never stalled... It was two hours of extreme upper end snowfall dumping 5" or so. It's probably been since Jan 2012 that we were selectively nailed. Since then it's been Snohomish Co., West Seattle, SeaTac, Marysville, ect. But not here!

Statistically we're pretty due given our location in the central Sound.

[smerfylicious]

10 minutes ago, MillCreekMike said:

Wow just got home. ZERO snow here. Not even anything coming down even though there’s echoes over me. Right when I passed the Highway 9 exit on Highway 2 the snow just vanished. That was so depressing. Maybe north Everett wasn’t the best spot to move. Been burned twice in a row

Should moved to my hood

[Cold Snap]

Does anyone have a good idea on when the convergence zone activity is supposed to peak?

[bishbish777]

Also huge north shift from 00Z Euro last night to 12Z/18Z today. Euro within 72 hours is not what it's made out to be. 

[TT-SEA]

Just now, bishbish777 said:

Also huge north shift from 00Z Euro to 12Z/18Z today. Euro within 72 hours is not what it's made out to be. 

Well that event starts in 36 hours so it might be narrowing in on reality now.   But who knows at that point.

[KingstonWX]

1 minute ago, Cold Snap said:

Does anyone have a good idea on when the convergence zone activity is supposed to peak?

Peak has probably occurred already and we are wringing out the atmosphere now. 

[Meatyorologist]

Just now, bishbish777 said:

Also huge north shift from 00Z Euro last night to 12Z/18Z today. Euro within 72 hours is not what it's made out to be. 

This is a difficult pattern for any model to nail. But there is a good sentiment here in that no model, not even the vaunted Euro, is a godsend.

[Kolk1604]

5 minutes ago, bishbish777 said:

Wow 18Z Euro with the complete rug pull for Seattle metro. Hard to believe we could get through this with no snow in Seattle but that's definitely on the table now. 

Not really

Nice try though. EPS is unchanged and still cold 

[SnowWillarrive]

Just now, Kolk1604 said:

Not really

Nice try though. EPS is unchanged and still cold 

I like your optimism. 

[Ice_is_Everywhere]

So, how likely is it that the Euro is wrong at this point, especially with the GFS (even with all the crap it gets) going in seemingly the opposite direction?

[Gradient Keeper]

Root for the next 2-3 runs to sink that low south for Tuesday! Ya gotta believe! 18z GEFS trending colder more inline with the EPS. Crazy. It's not often we see the Euro more aggressive with an arctic blast/CAA it's always the opposite. WHAT just happened at the end of the Raiders/Patriots game! NEVER seen that!!!!

00z GFS in 3 hours 4 minutes

[MikeInEverett]

Surprised a WWA was just issued for Everett and vicinity up to Stanwood for an additional two inches of snow when it looks like precip is moving out right now. Doesn’t really make sense.

[bishbish777]

Just now, Kolk1604 said:

Not really

Nice try though. EPS is unchanged and still cold 

I'm not sure what you're looking at, but 18Z was significantly north with Tues/Wed, so Seattle is just cold rain. EPS is less and less relevant the closer we get. Not saying it's gonna happen how Euro shows, but it's pretty clear that 18Z was worse for Seattle.

[MR.SNOWMIZER]

What if the euro is wrong on the temp outputs? Just wanted to throw that out there because it's looking like the euro might be to mild on this airmass moving in.

[KingstonWX]

Just now, MillCreekMike said:

Surprised a WWA was just issued for Everett and vicinity up to Stanwood for an additional two inches of snow when it looks like precip is moving out right now. Doesn’t really make sense.

Wouldn't be the first time they underreacted and then overreacted in response. 

[Meatyorologist]

1 minute ago, MR.SNOWMIZER said:

What if the euro is wrong on the temp outputs? Just wanted to throw that out there because it's looking like the euro might be to mild on this airmass moving in.

I was getting that feeling based on Tuesday temp outputs. Super aggressive with the southerly flow despite offshore gradients.

[Blizzard777]

Will get caught up in a bit as I’m outside working. Everything has gone. That’s a good sign without looking at the radar  

I also see a long dark cloud approaching !

[Perturbed Member]

Mark Nelsen:

We've put the First Alert Weather Day logos on THURSDAY & FRIDAY on the 7 Day Forecast.  That means there's a good chance weather will impact your day during that time.  Especially Portland metro, Gorge, and lowlands from Longview to Eugene.  It's possible freezing rain falls at some point along the northern coast too...but we're still 4 days out...
Models are in pretty good agreement that a classic setup for snow or freezing rain (mainly freezing rain) will be in place sometime Thursday through Friday in at least part of the metro area (or possibly all).  The setup is when very cold air comes through the Columbia River Gorge and pours out into the western valleys near sea level. Then warmer and moist Pacific air moves in overhead.  Snow levels rise to around 7,000' or so by Friday in the Cascades!
Most likely this will be a freezing rain event; an ice storm if we get significant amounts of it. Freezing rain is liquid rain that falls into below freezing air and freezes as a smooth icy glaze on contact.  When we get more than about 1/2", damage starts to become widespread with falling limbs and power lines.
We're still 4-5 days away, so not many details for now.  But we are confident that at least part of the metro area (and all of Gorge) has a big winter weather event on the way.  And of course this is a huge travel time leading to Christmas Eve on Saturday, so we'll be on top of it.  My gut feeling is that you won't want to be on I-84 between Portland The Dalles Friday and Saturday.  Sorry about the poor timing!  I'll get a detailed blog post done late this evening or tomorrow morning

[MossMan]

14 minutes ago, MillCreekMike said:

Weenie mode has been activated for me it seems  

We can be weenie brothers! 

[Sandy rocks]

Is something suppose to happen on or near Mt. Hood?

[MossMan]

26.8

[Kolk1604]

3 minutes ago, bishbish777 said:

I'm not sure what you're looking at, but 18Z was significantly north with Tues/Wed, so Seattle is just cold rain. EPS is less and less relevant the closer we get. Not saying it's gonna happen how Euro shows, but it's pretty clear that 18Z was worse for Seattle.

EPS/GEFS are way colder than their operational models. I don't trust how much the Euro is moderating temps. 

[TT-SEA]

1 minute ago, Meatyorologist said:

I was getting that feeling based on Tuesday temp outputs. Super aggressive with the southerly flow despite offshore gradients.

Flow is not offshore on Tuesday morning per the ECMWF... strong south wind ahead of low.    It all comes down to low strength and track.

[The Cats Meow]

32 minutes ago, TT-SEA said:

18Z ECMWF coming in north on Tuesday... here through 1 p.m.

Oh my.  Ha ha ha ha ha!  Those temps for my house don't look any different than they did today.  About 41.  LOL!

[Meatyorologist]

5 minutes ago, Gradient Keeper said:

Root for the next 2-3 runs to sink that low south for Tuesday! Ya gotta believe! 18z GEFS trending colder more inline with the EPS. Crazy. It's not often we see the Euro more aggressive with an arctic blast/CAA it's always the opposite. WHAT just happened at the end of the Raiders/Patriots game! NEVER seen that!!!!

00z GFS in 3 hours 4 minutes

Just watched the clip that came out! WTAF?!?!?! Laughing my ass off with a cloud of white outside. Good evening.

[bishbish777]

3 minutes ago, MR.SNOWMIZER said:

What if the euro is wrong on the temp outputs? Just wanted to throw that out there because it's looking like the euro might be to mild on this airmass moving in.

That could also be connected to it sending the system farther north than other guidance, no? I think there's still decent model support for a more southerly track that it's not "over"..