PNW December 2022 - Part II

[MikeInEverett]

Precip really starting to enhance around Bellingham!

[Rubus Leucodermis]

Probably my favourite radar pattern: a choo-choo train of cells forming over the Strait, heading my way.

[yellowstone]

Just got a report from a friend in Bellingham the snow has started. 

[TT-SEA]

Just now, yellowstone said:

Just got a report from a friend in Bellingham the snow has started. 

Just got text from my mom and she said huge flakes falling... they live just north of Lake Whatcom.

[Blizzard777]

From the ex

Sandy Shores Ferndale Wa. 
blowing arctic snow 

[Cloud]

Note: this is just for the general pattern. 
 

But the GFS has been quite persistent with the return of the AL in la la land. Pretty much flipping the script we’ve been seeing. Would be quite interesting to see when we can get the block reconfigured again. 

[Poulsbo Snowman]

2 minutes ago, Blizzard777 said:

From the ex

Sandy Shores Ferndale Wa. 
blowing arctic snow 

My ex never shared sexy pictures like this with me.

[SilverFallsAndrew]

2 minutes ago, Cloud said:

Note: this is just for the general pattern. 
 

But the GFS has been quite persistent with the return of the AL in la la land. Pretty much flipping the script we’ve been seeing. Would be quite interesting to see when we can get the block reconfigured again. 

Doesn’t seem like a persistent AL we have seen in past years. 

[Cloud]

1 minute ago, SilverFallsAndrew said:

Doesn’t seem like a persistent AL we have seen in past years. 

Nope….  And the last few years were extremely hard to get rid of as well. 

[Blizzard777]

2 minutes ago, Poulsbo Snowman said:

My ex never shared sexy pictures like this with me.

She even invited me up

I’m prepping for my road trip though so passed on the offer.  Would of been fun though 

[GoldenEars]

Heavy snow and east winds ripping up the Fraser right now. Visibility is falling fast here and I even have some drifts forming!

[SnowWillarrive]

The overnight discussion from Seattle NWS is weak. You wouldn’t think anything really interesting happening. 

[ShawniganLake]

17 minutes ago, Hawksfan2008 said:

 

 

Bullseye. I’m in the white. 

[ShawniganLake]

Wow. Parts of metro Vancouver are getting crushed right now. 

[Blizzard777]

1 hour ago, Blizzard777 said:

Relieved this is finally playing out and we can enjoy excitement from others in the target zones! 

Holding up….this is and hour later 

[lowlandsnow]

When does UKMET begin?

[TT-SEA]

12Z WRF does not even show the c-zone tonight.    Very strange.  

[Cascadia_Wx]

Not sure how much it matters at this range but there is pretty good ensemble support from the 12z GEFS for those cold surface temps for PDX. Also interesting how the ensemble mean wants to put PDX in the freezer starting Tuesday.

[Rubus Leucodermis]

9 minutes ago, ShawniganLake said:

Wow. Parts of metro Vancouver are getting crushed right now. 

This thing may seriously overperform the official forecast of 2–4". HRDPS says about 10" for Coquitlam and 6" IMBY today.

[Front Ranger]

3 minutes ago, TT-SEA said:

12Z WRF does not even show the c-zone tonight.    Very strange.  

I believe the WRF has been fairly useless in Arctic front situations, yeah?

[Deweydog]

Models are really starting to come into alignment on the powerful low level advection, settling for now on Wednesday evening. If it manages to dry outflow well into the 20’s, it could end up being one for the books.  Most models show upper level advection yielding thicknesses no lower than about 530dm with the pattern evolution. Having trouble finding any examples of such a gradient with PDX temps advecting below 25 or so.

February 2021 dropped PDX to an impressive 24 with the precip dynamic, however in all likelihood that would have been temps about five degrees warmer in dry outflow scenario. 

January 2004, which still might be the best overall analog had thicknesses drop to 521dm with 850mb temps down to -10c or so at onset, plus the low level push was a bit more incremental.

Others like December 1995 and January 2005 were much weaker than currently progged when it comes to low level advection and probably at the bottom (top?) end of the spectrum of possibilities. 

[TacomaWx]

37 here…had some chunky rain under a heavier shower just a bit ago. Definitely could see some flakes fly before this evening. Also wouldn’t be surprised if we don’t get our 2nd sub 40 high in a row. 

[SnowWillarrive]

Vancouver BC getting blasted 

[TT-SEA]

Just now, Front Ranger said:

I believe the WRF has been fairly useless in Arctic front situations, yeah?

Yes... but not sure this is an arctic front down here.    Its not like there will be a north wind and cold air pouring in down here tonight.   The ECMWF shows a SW wind in Seattle even tomorrow.

 

[North_County]

Snowglobe up here.

[Doinko]

4 minutes ago, Front Ranger said:

I believe the WRF has been fairly useless in Arctic front situations, yeah?

This was before the November 2010 event

[MikeInEverett]

Just realized. This is another cold/snow event starting on a Sunday. Others in recent years:

Super Bowl 2017

Super Bowl 2019

January 2020

December 2021

The only notable event that didn’t begin on a Sunday in recent years was February 2021. Super random but an odd fun fact.

[Rubus Leucodermis]

 

[Blizzard777]

5 minutes ago, Front Ranger said:

I believe the WRF has been fairly useless in Arctic front situations, yeah?

They really should put this info right up front on the model run…fixed for now

[MR.SNOWMIZER]

Pelly ranch now down to a incredible -52. This might be the coldest airmass I've ever tracked up there I can remember. 

[SilverFallsAndrew]

Just got a snow video from my wife, looks like it’s coming down pretty good. 

[Cascadia_Wx]

5 minutes ago, Deweydog said:

Models are really starting to come into alignment on the powerful low level advection, settling for now on Wednesday evening. If it manages to dry outflow well into the 20’s, it could end up being one for the books.  Most models show upper level advection yielding thicknesses no lower than about 530dm with the pattern evolution. Having trouble finding any examples of such a gradient with PDX temps advecting below 25 or so.

February 2021 dropped PDX to an impressive 24 with the precip dynamic, however in all likelihood that would have been temps about five degrees warmer in dry outflow scenario. 

January 2004, which still might be the best overall analog had thicknesses drop to 521dm with 850mb temps down to -10c or so at onset, plus the low level push was a bit more incremental.

Others like December 1995 and January 2005 were much weaker than currently progged when it comes to low level advection and probably at the bottom (top?) end of the spectrum of possibilities. 

How was late December 1968 in the upper levels? I know that was a low level beast spawned by somewhat of a glancing blow to our NE, but I would imagine it probably had better upper level support at some point?

[ShawniganLake]

35 minutes ago, Front Ranger said:

Wow, Williams Lake in southern BC is already down to -10. And should stay below 0 for at least the next 96 hours.

I see Environment Canada has issued an extreme cold warning for the region. Seems pretty rare.

Clinton is -14 with a windchill of -40, they are south of Williams Lake

[MossMan]

Getting darker and starting to snow a little. 

Edited December 18, 2022 by MossMan

[SnowWillarrive]

Just now, MossMan said:

Getting darker and starting to snow. 

Spread the wealth 

[ShawniganLake]

6 minutes ago, MR.SNOWMIZER said:

Pelly ranch now down to a incredible -52. This might be the coldest airmass I've ever tracked up there I can remember. 

They will probably hit -60 with this.  They hit -64 in early January this year. 

[Deweydog]

4 minutes ago, Cascadia_Wx said:

How was late December 1968 in the upper levels? I know that was a low level beast spawned by somewhat of a glancing blow to our NE, but I would imagine it probably had better upper level support at some point?

Yeah, 850’s dropped to around -13c with that on the 29th I believe, but it isn’t a terrible analog. That thing lost it’s blocking support pretty early on and ended up racing eastward once it made it just south of the border followed by a decent undercut/-EPO period.

[Blizzard777]

Friday Harbor cam looking NW and winds out of the south…..so close but yet so far 

[TacomaWx]

Just now, Blizzard777 said:

Friday Harbor cam looking NW and winds out of the south…..so close but yet so far 

Some of the first places to watch on the temp map is orcas island and anacortes. Once you see the temps plunge there it’s finally moving out of whatcom county. 

[TT-SEA]

World Cup final is insane... France just tied it again with only 2 minutes left in first OT.