PNW December 2022 - Part II

[Gradient Keeper]

Wait. There it comes, but it's not going to dig much into eastern Washington it seems.

[TacomaWx]

It looks like that lows going to come in further south. 

[Perturbed Member]

Pretty dry from that Tuesday system but look how much colder the temps are.

 

A 10F difference in PDX between the 00z and 18z GFS. Even a couple of degrees colder in SEA.

 

[TacomaWx]

Yep! There it is all snow event in Puget sound now. 

[Gradient Keeper]

Yeah just clips eastern Washington.

[Cascadia_Wx]

1 minute ago, Gradient Keeper said:

Yeah just clips eastern Washington.

I think a clip is all it takes at this case. The situation is all about low level cold which quickly becomes decoupled from the 500mb pattern.

[VancouverIslandSouth]

The low looks weaker and further south on the 0z GFS, it's not going to do much to dislodge the low level Arctic air once it comes ashore.

[Doinko]

3 minutes ago, Perturbed Member said:

Pretty dry from that Tuesday system but look how much colder the temps are.

 

A 10F difference in PDX between the 00z and 18z GFS. Even a couple of degrees colder in SEA.

 

Weird run so far. I think it'll be an outlier because of how different it is to basically everything. That second cold shot is a bit farther east as well

[SilverFallsAndrew]

Hmmm

Edited December 18, 2022 by SilverFallsAndrew

[TacomaWx]

Yeah it definitely doesn’t get that cold after the system slides SE…but I get the feeling it’s going to trend colder. Things are clearly moving towards the euro now it looks like. 

[Timmy]

Conflicting reports!

[Gradient Keeper]

Day 4 (4-run trend)

[Gradient Keeper]

2 minutes ago, Cascadia_Wx said:

I think a clip is all it takes at this case. The situation is all about low level cold which quickly becomes decoupled from the 500mb pattern.

That massive arctic high in Montana all but assures a low level blast.

[Nov1985]

5 minutes ago, TacomaWx said:

It looks like that lows going to come in further south. 

Like the other models, it's more of just a little wave of moisture now. 

[TT-SEA]

Ridge is building in faster on Wednesday... but there is still some snow that morning around Seattle to make up for getting nothing on Tuesday.

Tuesday is still anyone's guess.

[Requiem]

Works out great this run, short term improvements and some small wobbles if anything 

[snow_wizard]

The GFS sure gets weird with the snowfall on Tuesday (actually more like Tuesday and Tuesday night now).  Much different angle of attack than the other models.  At any rate a lot colder for the Seattle area than earlier runs in that period.

[bainbridgekid]

Tomorrow will be a very interesting day. The 0z GFS looks quite robust with the Arctic Front/Convergence and gets things started pretty early in the day North of Seattle. Actually spits out 2.8” of snow in Everett before 1 PM.

Feels like these things usually take a few hours longer than modeled to slide South but that often ends up being a good thing because it keeps the band of snow going longer.

[BLI snowman]

Unfortunately the 00z GEM appears to have taken a step towards the GFS, which the RGEM run was an early hint at.

[Perturbed Member]

1 minute ago, TacomaWx said:

Yeah it definitely doesn’t get that cold after the system slides SE…but I get the feeling it’s going to trend colder. Things are clearly moving towards the euro now it looks like. 

Still gets chilly at the surface but much warmer aloft compared to the euro. 

 

 

 

[Doinko]

GFS also barely brings any precip on Thursday. Just a strong cold east wind

[SouthHillFrosty]

Tipsy at a holiday party in a Santa suit. How does the models look?

[snow_wizard]

4 minutes ago, Gradient Keeper said:

Day 4 (4-run trend)

Still so herky jerky compared to the ECMWF.

[Perturbed Member]

The Canadians have betrayed us....

[Requiem]

1 minute ago, BLI snowman said:

Unfortunately the 00z GEM appears to have taken a step towards the GFS, which the RGEM run was an early hint at.

Simply absurd how little consistency there is for something so close 

[Timmy]

Andrew, if you want devastating you’ll have to look at the gem.

 

20 degrees warmer for OLM than its 12z

Edited December 18, 2022 by Timmy

[Gradient Keeper]

Day 5

[snow_wizard]

1 minute ago, SouthHillFrosty said:

Tipsy at a holiday party in a Santa suit. How does the models look?

Snow happens either Monday night into Tuesday or Tuesday night into Wednesday for our area depending on model.

[Christensen87]

How frustrating, SO much cold air to work with…

[Requiem]

And I thought we would have some confidence by now... give us a break ffs

[yellowstone]

3 minutes ago, snow_wizard said:

Snow happens either Monday night into Tuesday or Tuesday night into Wednesday for our area depending on model.

Let’s just assume then it will start snowing by Monday sunset and won’t stop until sometime Wednesday.

[MossMan]

So now this thing is over by Tuesday? I am so confused. 

[Perturbed Member]

This feature is so incredibly volatile, given how many times multiple models have flipped back and forth between developing that northern energy into a closed low or just leaving it as a less organized wave. Such a subtle thing in the grand scheme of things but has massive implications for us. Hard to believe that even 48-60 hours out the models are still struggling to lock this down. 

[MR.SNOWMIZER]

Wow complete cave on the cmc to the gfs lol. 

[Ice_is_Everywhere]

3 minutes ago, Timmy said:

Andrew, if you want devastating you’ll have to look at the gem.

Gross.

[Terreboner]

OT, but for those of you that care.  Snow should start in earnest before this Buffalo game ends.  Moving in now.

[Doinko]

Just now, MossMan said:

So now this thing is over by Tuesday? I am so confused. 

ICON brings the low south so snow for SW WA mostly and the South Sound. Then major ice storm for Portland

GFS looks kind of strange, brings some light snow to the Sound then very cold east wind

GEM is bad

[dhoffine]

See what I'm talking about, this stuff is plain weird and confusing.  Its either going to be cold and no snow, or cold and 10 inches by Wednesday...  WHO FREAKING KNOWS!

[Requiem]

Just now, Perturbed Member said:

This feature is so incredibly volatile, given how many times multiple models have flipped back and forth between developing that northern energy into a closed low or just leaving it as a less organized wave. Such a subtle thing in the grand scheme of things but has massive implications for us. Hard to believe that even 48-60 hours out the models are still struggling to lock this down. 

At the end of the day they're just computers but you'd think with the amount of money they pump into these things they'd be somewhat accurate once in a while.

[Joshua Lake Oswego]

Can we just get some dang rain please. I’m tired of these long dry streaks in our wettest months.