January 2024 Weather in the PNW (Part II)

[TT-SEA]

Just now, Frontal Snowsquall said:

Wow, moisture way south. Misses us all.

Is that a southward shift from 00Z run?

[Olive1010]

5 minutes ago, Kolk1604 said:

ensambles for the win! Whos with me? 

Another win win for everybody

[BLI snowman]

14 minutes ago, Mid Valley Duck said:

I’ve never seen a spread like this on the GEFS. The op and control run have an 11c spread at hour 90!

 

Looks like the OP is the village idiot even among its own guidance.

Edited January 9 by BLI snowman

[iFred]

Meetup details - 

 

[Front Ranger]

9 minutes ago, MR.SNOWMIZER said:

Those are all different times.

They are different runs, same verification time.

[TT-SEA]

Just now, BLI snowman said:

Looks like the OP is an idiotic outlier even among its own guidance.

Big southward shift incoming eventually on GFS.  

[Frontal Snowsquall]

1 minute ago, TT-SEA said:

Is that a southward shift from 00Z run?

Yeah this was 00z last night.

 

[GobBluth]

7 minutes ago, TT-SEA said:

And then you have the EPS which was bullish on the jet stream returning by late next week.   No clue what will happen.

Seems splitty

[westcoastexpat]

For Seattle folks, here are the 12Z GFS snowfall ensembles (in centimeters)

[Mid Valley Duck]

3 minutes ago, TT-SEA said:

Is that a southward shift from 00Z run?

About 250 miles further south.

[TT-SEA]

Just now, Frontal Snowsquall said:

Yeah this was 00z last night.

 

Wow... that is a massive southward shift in 12 hours.  

[Frontal Snowsquall]

Onto the 12 EURO and GraphCast.  

[Rubus Leucodermis]

1 minute ago, TT-SEA said:

Big southward shift incoming eventually on GFS.  

[Frontal Snowsquall]

2 minutes ago, TT-SEA said:

Wow... that is a massive southward shift in 12 hours.  

I wasn’t expected that. But I think GFS and UKMET are outliers. But we’ll see.

[Perturbed Member]

6 minutes ago, TT-SEA said:

Is that a southward shift from 00Z run?

It appears to have pulled a 06z ICON and went way south from its 00z run. 

12z vs 00z

[SouthHillFrosty]

5 minutes ago, TT-SEA said:

Big southward shift incoming eventually on GFS.  

A little shift south on the 12z ensembles

[TT-SEA]

Just now, Frontal Snowsquall said:

I wasn’t expected that. But I think GFS and UKMET are outliers. But we’ll see.

Totally agree... the GFS and UKMET have to be the very outer edges of possible outcomes.  

[Randyc321]

Wow.

[snow_wizard]

The 12z GEFS is a good 2C colder with the 850s late in the week compared to the 6z.

[Hawksfan2008]

Ukmet and CMC both perform well at this range compared to the GFS. It’s also far enough out the EURO is still a leg up on all of them. Big run coming up! 

[MossMan]

16 minutes ago, Kolk1604 said:

ensambles for the win! Whos with me? 

I’m good with that! 

[Tyler Mode]

GEM has it briefly switching to rain, then freezing rain, sleet and eventually back to snow Friday night into Saturday as the cold and east wind really take over.

[TT-SEA]

Worth mentioning the 06Z ECMWF did show arctic air reaching  Seattle.   And inside of 90 hours its just about impossible to bet against the ECMWF.

[snow_wizard]

The 8 to 10 day period has some real potential to get interesting again.

[Phil]

There is something to be said for internal consistency in guidance. So rare that I ever say this, but given the relative stability of the GFS/GEFS suite (relative to other guidance) I’d hedge ~65-70% in that direction, with a 30-35% hedge towards other guidance. At least in terms of 500mb pattern.

Vice versa, guidance with the coldest solutions (such as the ICON) have been the most unstable with their solutions at 500mb (for what reason(s), I don’t know).

Though if there’s a mesoscale element to the model differences related to topography/etc, that’s something you all would understand better than me, in which case my opinions above are probably moot. I’m not great with mesoscale dynamics in unfamiliar regions (I’m slowly learning how that works in the PNW but can’t master it without living there).

[BLI snowman]

7 minutes ago, TT-SEA said:

Big southward shift incoming eventually on GFS.  

18z GFS sending that thing to Prince Rupert.

[MR.SNOWMIZER]

9 minutes ago, TT-SEA said:

Big southward shift incoming eventually on GFS.  

I will bet 50 bux in the end it comes in between Astoria and long beach.

[SouthHillFrosty]

[snow_wizard]

3 minutes ago, TT-SEA said:

Worth mentioning the 06Z ECMWF did show arctic air reaching  Seattle.   And inside of 90 hours its just about impossible to bet against the ECMWF.

I wonder if the extra data they have been dropping into the GFS is causing some kind of an overload, or maybe too much emphasis on the Pacific.  Really weird how stubborn it is right now.

[Frontal Snowsquall]

12z UKMET has the trough dig back west on Monday.

 

[FrozenBites]

Just now, MR.SNOWMIZER said:

I will bet 50 bux in the end it comes in between Astoria and long beach.

Good bet. The models fluxation is making this fun to keep an eye on.

[MossMan]

Northern Cali will be the big winner it looks like now! 

[Front Ranger]

FWIW, the FV3 hi res shows Portland area getting clobbered pretty good tonight.

 

Also shows a decent Arctic front CZ signature later for Puget Sound.

[Frontal Snowsquall]

2 minutes ago, SouthHillFrosty said:

Both models dropping off lately due to the complexity of the pattern. But wow at the GFS.

[snow_wizard]

416 guests!  I guess things are getting interesting.

[LowerGarfield]

33 minutes ago, Rubus Leucodermis said:

I've looked at the models and they all show the cold, dry air making it to Seattle.

That will involve one air mass pushing another out. The boundary between the two would be a front, would it not?

Cliff

[Christensen87]

My sister is subbing in Enumclaw and the teachers want my prediction if school will be cancelled Friday due to weather. My first thoughts are of course, no way to tell yet. GFS has snow coming in that day, so it could be a good idea. Don’t think the wind would be an issue yet. What do you guys think? 

[Weiner Warrior]

The deer came through the yard yesterday. They only stop by before snow. 100% guaranteed bellevue gets snow.

[Rubus Leucodermis]

1 minute ago, LowerGarfield said:

Cliff

He says the roads are too warm for an arctic front to advance.

[snow_wizard]

I thought people were saying the UKMET was warm.  Sure doesn't look like it.