PNW December 2022, winter might be coming; but mostly canceled.

[Slushy Inch]

Not terrible. 

[MR.SNOWMIZER]

Depending what happens this weekend it could really start getting deep out here.

[Cascadia_Wx]

1 minute ago, 12345WeatherNerd said:

Not terrible. 

Crazy amount of high latitude blocking.

[Kolk1604]

EPO looks good, PNA can use some work. Maybe it's setting up for another magical christmas

[smerfylicious]

Need a refresher, snow is a week old now and I only have about 5" left in the front yard. Need enough to make it to Christmas  

[Slushy Inch]

Beautiful return to ridge bridge stalling us in a cold pattern!

[SilverFallsAndrew]

7 minutes ago, Cascadia_Wx said:

They strung together three in a row in February 2021. I think that was the last time there, although a lot of spots around the metro area (like here) managed a couple sub freezing highs late last December.

Generally in the situation the euro is showing a sub freezing high at PDX would be a bit of a stretch, but it’s possible if the cold pool develops enough east side. Mid December is probably the best time to sit under a ridge from a low level cold perspective. Also we go from a cool/cold trough to ridging which means we have cool air at the surface to start out with. That’s when we see really chilly low level

cold pools develop. We are probably about due, it’s been about 9 years since we had a really legit low level cold situation that didn’t start out with at least modified arctic air. 

[Slushy Inch]

Wow, continues to sit there!

[Kolk1604]

1 minute ago, 12345WeatherNerd said:

Wow, continues to sit there!

I just saw that. LR looks better. 

[Cascadia_Wx]

Praying for northern posters to get their snowpack refreshed in time for Christmas  

Edited December 6, 2022 by Cascadia_Wx

[Cascadia_Wx]

4 minutes ago, SilverFallsAndrew said:

Generally in the situation the euro is showing a sub freezing high at PDX would be a bit of a stretch, but it’s possible if the cold pool develops enough east side. Mid December is probably the best time to sit under a ridge from a low level cold perspective. Also we go from a cool/cold trough to ridging which means we have cool air at the surface to start out with. That’s when we see really chilly low level

cold pools develop. We are probably about due, it’s been about 9 years since we had a really legit low level cold situation that didn’t start out with at least modified arctic air. 

I’m really loving this forecast Andrew. I think all the high latitude blocking is making for clearer and colder than usual conditions there. Hope it keeps up. Would be a great setup to see the northern lights.

[Slushy Inch]

2 minutes ago, Kolk1604 said:

I just saw that. LR looks better. 

If both coasts are cold and under troughs in this period from the ridge bridge, would PNA be close to neutral?

[Kolk1604]

1 minute ago, 12345WeatherNerd said:

If both coasts are cold and under troughs in this period from the ridge bridge, would PNA be close to neutral?

I'm not really an expert on that. All I know is a negative PNA and EPO is a good thing. 

[SilverFallsAndrew]

One of my favorite and imo underrated cold snaps was late December 2010 through that first week of January. I know Jesse remembers that one. 

[Cascadia_Wx]

2 minutes ago, SilverFallsAndrew said:

One of my favorite and imo underrated cold snaps was late December 2010 through that first week of January. I know Jesse remembers that one. 

Loved that one too. That combined with the November and late February airmasses made for a well rounded winter. Gave way to an awesome spring and summer.

[Gradient Keeper]

17 minutes ago, Cascadia_Wx said:

Praying for northern posters to get their snowpack refreshed in time for Christmas  

LMAO I almost fell off my couch.

[Gradient Keeper]

19 minutes ago, Kolk1604 said:

I just saw that. LR looks better. 

Note the 500mb contours northerly = colder. Pretty dang nice pattern.

[MossMan]

19 minutes ago, Cascadia_Wx said:

Praying for northern posters to get their snowpack refreshed in time for Christmas  

Thanks Jesse! Finally a loving caring post for us up here.

[Slushy Inch]

1 minute ago, Gradient Keeper said:

Note the 500mb contours northerly = colder. Pretty dang nice pattern.

2008 redux anybody?

[TT-SEA]

Nice to see the Sierras wetter than normal over the next 15 days per the 12Z EPS...

[RentonHill]

1 minute ago, TT-SEA said:

Nice to see the Sierras wetter than normal over the next 15 days per the 12Z EPS...

The only thing the models love to take away more than precip from PDX is precip from CA

[Brian_in_Leavenworth]

Long range EPS is showing some signs of retrogression.  Compare it to the last couple of runs.  Of course hour 360 on today's wasn't on previous runs, but you get the idea.

 

 

 

 

[Slushy Inch]

1 minute ago, Brian_in_Leavenworth said:

Long range EPS is showing some signs of retrogression.  Compare it to the last couple of runs.  Of course hour 360 on today's wasn't on previous runs, but you get the idea.

 

 

 

 

It's much better than last run all the way through.

[Cold Snap]

18 minutes ago, SilverFallsAndrew said:

One of my favorite and imo underrated cold snaps was late December 2010 through that first week of January. I know Jesse remembers that one. 

I remember that one pretty well actually. I got 4 inches of snow and then I think we went into an inversion setup for the week following I had snow cover for over a week with that! Even though the snow fell over winter break I remember it was still on the ground once I got back to school.

[Gradient Keeper]

2 minutes ago, Brian_in_Leavenworth said:

Long range EPS is showing some signs of retrogression.  Compare it to the last couple of runs.  Of course hour 360 on today's wasn't on previous runs, but you get the idea.

 

 

 

 

That is a CLASSIC retrogression signal just in time for Christmas too! Ya gotta believe, and I'm telling ya, if you don't, it's just not gonna happen. C'MON!!!!

[LowerGarfield]

Snow is melting as we're now at 40 degrees but it looks cool having snow mixed with green.

[Slushy Inch]

1 minute ago, Gradient Keeper said:

That is a CLASSIC retrogression signal just in time for Christmas too! Ya gotta believe, and I'm telling ya, if you don't, it's just not gonna happen. C'MON!!!!

Whole period is pretty good.

[van city]

 

[Kolk1604]

6 minutes ago, Brian_in_Leavenworth said:

Long range EPS is showing some signs of retrogression.  Compare it to the last couple of runs.  Of course hour 360 on today's wasn't on previous runs, but you get the idea.

 

 

 

 

I feel like it looks way better on weathermodels lol 

 

 

[Gradient Keeper]

I've seen many situations exactly like what appears to be coming. A prolonged low level cold pool/ridge sets up, and after 5-7 days it backs off the coast and arctic air follows soon after. BOOK IT. MBG. I'm not cautiously optimistic either, I'm rather confident.

18z GFS in 1 hour 30 minutes
00z GFS in 7 hours 30 minutes
00z ECMWF in 9 hours 40 minutes

[MossMan]

Moderate drizzle and 36 degrees. Current kitchen view while I’m home eating lunch. 

[Brian_in_Leavenworth]

6 minutes ago, Kolk1604 said:

I feel like it looks way better on weathermodels lol 

 

 

I know, different web sites use different color schemes.  What got my attention is there the strongest part of the ridge has migrated too.  Hard to see on WB, but it does show the center is in the Northern part of the Gulf as opposed to just west of BC.

[TT-SEA]

1 minute ago, MossMan said:

Moderate drizzle and 36 degrees. Current kitchen view while I’m home eating lunch. 

Snowpack here looking more dilapidated too... 

[SilverFallsAndrew]

16 minutes ago, Brian_in_Leavenworth said:

Long range EPS is showing some signs of retrogression.  Compare it to the last couple of runs.  Of course hour 360 on today's wasn't on previous runs, but you get the idea.

 

 

 

 

I am probably wrong, but I feel like we are going to need a high amplitude ridge over us which ultimately migrates westward, before we can get any arctic air in here. I think we have a good shot of it happening late month through mid-January, but I just don't see it happening in the current pattern we have been in since around Thanksgiving. 

[SilverFallsAndrew]

Looking from a historical context, with what we have just gone through the first week of December, in some of those years where it was a precursor to something bigger, the worm turned hard back in our favor in that late December-early January period. 

[Brian_in_Leavenworth]

5 minutes ago, SilverFallsAndrew said:

I am probably wrong, but I feel like we are going to need a high amplitude ridge over us which ultimately migrates westward, before we can get any arctic air in here. I think we have a good shot of it happening late month through mid-January, but I just don't see it happening in the current pattern we have been in since around Thanksgiving. 

One good thing is that late December to early January is historically the coldest time of year, IIRC.  So actual bona-fide arctic air may not be necessary for a lot of people to score.  

[mtep]

45 minutes ago, Cascadia_Wx said:

I’m really loving this forecast Andrew. I think all the high latitude blocking is making for clearer and colder than usual conditions there. Hope it keeps up. Would be a great setup to see the northern lights.

Enjoy your trip! Iceland is such a cool country. I was able to visit in Feb of 2016 and was amazed by how 'mild' it is up there being so far north. The waterfalls and black sand beaches were straight up surreal. Was lucky enough to see the northern lights one night too! 

[SilverFallsAndrew]

1 minute ago, Brian_in_Leavenworth said:

One good thing is that late December to early January is historically the coldest time of year, IIRC.  So actual bona-fide arctic air may not be necessary for a lot of people to score.  

Very true. One of the best winter stretches I've had down here was the first week of January 2017. It was kind of a fail as far as true arctic air went, but we had some modified arctic air slip in and ended up having a very cold low level airmass. A lot of valley locations ended up hitting the mid teens even without snow cover, which set up a nice overrunning event from EUG to PDX on the 7-8th. The events that happened a few days later kind of fade the memory of the previous week for many, but for many areas south of Portland that was the coldest week of that winter. EUG had back to back lows of 13 on the 5th and 6th and then a 29/24 day on the 7th with 4" of snow. 

Salem bottomed out at 14 on the 6th, and then had a 29/23 day on the 7th. 

Both locations also recorded sub-freezing highs on 1/13/2017. Eugene would record one on the 14th as well, and this would end up being the last time they had a sub-freezing high. Salem would not record another one until the ice storm of February 2021. 

However, 1/7/2017 is the last time both locations had a sub-30 high. 

Neither location has rivaled the lows of 14 and 13 respectively that they achieved on 1/6/17. 

In fact, if I am not mistaken the last time Salem saw a low in the teens was 1/15/17 and at EUG 1/6/17... Both incredibly long stretches for those locations. 

I digress...

[MossMan]

Actually have some lumps in with the liquid precip! Going to drive up the the highest location near my house to see if there is any difference. 

[TT-SEA]

1 minute ago, MossMan said:

Actually have some lumps in with the liquid precip! Going to drive up the the highest location near my house to see if there is any difference. 

I had a few fat snowflakes here earlier... but out here you would have to go up 1,000+ feet to get to sticking snow.