PNW December 2022 - Part II

[MR.SNOWMIZER]

Massive snow storm now for the sound on Friday. 

[The Cats Meow]

Just now, MR.SNOWMIZER said:

Massive snow storm now for the sound on Friday. 

Not trying to be negative but it was Tuesday, then Thursday, now Friday......LOL!

[Cloud]

Upper teens Thursday evening when the next round starts after Tuesday. Cold air is locked into place up until then. 
 

mentioned this last night but the transition from snow to mixed to rain kept getting pushed back and trending that way. Big snow Thursday evening into Friday 

[T-Town]

Olympics peeking out this morning. 

[Rubus Leucodermis]

On this day in 1990 I was watching Seattle get hammered by snow as an arctic front swept in.

[Frontal Snowsquall]

9 minutes ago, Doinko said:

Cold east wind arrives Wednesday evening

 

 

12z GFS shows the system arriving Thursday evening. Starts off as snow PDX North before changing to sleet.

 

[FroYoBro]

Sleet storm!!!!!!!!11111111111!!!!!1111111

[Doinko]

Just now, Frontal Snowsquall said:

12z GFS shows the system arriving Thursday evening. Starts off as snow PDX North before changing to sleet.

 

Cold layer is trending deeper lol??

[TT-SEA]

Lots of snow per the 12Z GFS with the transition event now on Friday.

[TacomaWx]

Gem is farther south than the 00z but not quite far enough for the south sound goes right over Tacoma. 

[Front Ranger]

2 minutes ago, Hour364Please said:

Not trying to be negative but it was Tuesday, then Thursday, now Friday......LOL!

Tuesday is still very much on.

[Doinko]

Just now, TT-SEA said:

Lots of snow per the 12Z GFS with the transition event now on Friday.

Temps in Portland look frigid

[SilverFallsAndrew]

Yeah most of the metro gets a nice period of sleet. 

[TT-SEA]

Much less freezing rain for the Seattle area compared to the 06Z run.  

[Cloud]

Just scattering and lingering showers at this point. Mostly snow from Seattle north. 

[The Cats Meow]

It will be neat to see what happens when some of that cold air spills out over the water.  Sometimes it can spin up a surprise or three.

[Doinko]

Just now, TT-SEA said:

Much less freezing rain for the Seattle area compared to the 06Z run.  

How much sleet accumulation?

[Front Ranger]

BLI down to 28, even though outflow hasn't really amped up yet. Wind is NE at just 9 mph.

[TT-SEA]

Just now, Doinko said:

How much sleet accumulation?

 

[TT-SEA]

3 minutes ago, TacomaWx said:

Gem is farther south than the 00z but not quite far enough for the south sound goes right over Tacoma. 

Good agreement on track now.   I doubt this would actually be rain in King County though.  

 

[Rubus Leucodermis]

5 minutes ago, Hour364Please said:

Not trying to be negative but it was Tuesday, then Thursday, now Friday......LOL!

It’s really depressing when the models keep delaying the arrival of snow like this. Why can’t they ever do the same for pineapples?

Oh, wait…

[SilverFallsAndrew]

The GEM is actually more aggressive with the low level cold than the GFS. Freezing line south of Eugene by Wednesday evening. 

[SnowWillarrive]

12 minutes ago, ShawniganLake said:

No thank you. It’s fine where it is. 

We can’t allow customs to hold it up. 

[Rubus Leucodermis]

1 minute ago, Front Ranger said:

BLI down to 28, even though outflow hasn't really amped up yet. Wind is NE at just 9 mph.

We’ve been tracking its progress since yesterday on the Canadian forum. Wind-wise, this one has been surprisingly mild and subtle so far.

[SilverFallsAndrew]

My wife just messaged and apparently it snowed about 1/4” at our house last night. Wasn’t expecting that…

[Prairiedog]

18 minutes ago, Doinko said:

Back to back maxes in the teens in Portland? Wow. Looks like some extremely strong east winds as well

32 in Eugene as well... Could it happen?

I'd love that but I think that's overdone.  It would help if there was some snow cover and we'd need some clearing.  Obviously temps on the east side will be important but with as much warming coming in overhead sometime Thursday, it's going to be tough being that cold at the lowest levels.  Sure would be nice but I'm not in the mood for more ice. 

[Cloud]

Surface details is meh at this range but wanting to show when it would go above freezing again. But the trend is colder for Saturday still

[TacomaWx]

2 minutes ago, SnowWillarrive said:

We can’t allow customs to hold it up. 

It’s into whatcom county already…but no further south or west so far. Still in the mid 30s in the San Juan islands. 

[Skier B]

9 minutes ago, MR.SNOWMIZER said:

Massive snow storm now for the sound on Friday. 

It doesn't even look like KSEA gets much rain after the snow stops on Friday?  

Snow on the ground for Christmas??

[SilverFallsAndrew]

2 minutes ago, Prairiedog said:

I'd love that but I think that's overdone.  It would help if there was some snow cover and we'd need some clearing.  Obviously temps on the east side will be important but with as much warming coming in overhead sometime Thursday, it's going to be tough being that cold at the lowest levels.  Sure would be nice but I'm not in the mood for more ice. 

I like the GEM solution of bringing the cold in Wednesday evening. Would suck to have PDX at 33 at midnight Thursday and 21 at 4pm. 

[Frontal Snowsquall]

7 minutes ago, Doinko said:

Cold layer is trending deeper lol??

I’m hoping so. We won’t know the exact details probably until less than 24 hours away. 

[snow maniac]

Looks like the Olympic rain shadow is going to kill a-lot of my snow 

[Rubus Leucodermis]

1.4". Dumping.

[SilverFallsAndrew]

GEM has a ton of sleet in the metro and willamette valley. 

[Cascadia_Wx]

1 minute ago, Prairiedog said:

I'd love that but I think that's overdone.  It would help if there was some snow cover and we'd need some clearing.  Obviously temps on the east side will be important but with as much warming coming in overhead sometime Thursday, it's going to be tough being that cold at the lowest levels.  Sure would be nice but I'm not in the mood for more ice. 

Snow cover and clearing don’t really play a role here. This isn’t radiational cooling. It’s low level cold air advection.

That said I also agree the amount of CAA being shown Wednesday into Thursday seems too good to be true. But it’s worth mentioning that the GFS was pretty slow to bite on the low level cold air with this thing, and now it’s totally onboard. Maybe when they did the upgrade they made the GFS more conservative with CAA since it used to be extremely aggressive. In which case having it strongly in that camp now could be a good sign.

[MossMan]

1 minute ago, Rubus Leucodermis said:

1.4". Dumping.

Throw me a snowball down here!

[Doinko]

GEM also has some very cold outflow

 

[MR.SNOWMIZER]

2 minutes ago, Skier B said:

It doesn't even look like KSEA gets much rain after the snow stops on Friday?  

Snow on the ground for Christmas??

Darn good chance Seattle has a white Christmas. 

[Rubus Leucodermis]

30.9˚F. Buh-bye freezing point. See you again next weekend?

[Doinko]

Just now, Cascadia_Wx said:

Snow cover and clearing don’t really play a role here. This isn’t radiational cooling. It’s low level cold air advection.

That said I also agree the amount of CAA being shown Wednesday into Thursday seems too good to be true. But it’s worth mentioning that the GFS was pretty slow to bite on the low level cold air with this thing, and now it’s totally onboard. Maybe when they did the upgrade they made the GFS more conservative with CAA since it used to be extremely aggressive. In which case having it strongly in that camp now could be a good sign.

GFS, GEM and Euro have some amazing CAA.