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

[SouthHillFrosty]

Not good 

[Gradient Keeper]

Day 5.5 low level cold begins

[SilverFallsAndrew]

3 minutes ago, Gradient Keeper said:

True it would be. Many more model runs to go before this is locked in and it could easily shift south like the GFS did with the previous Snowy event. The best is yet to come just before Christmas.

00z ECMWF in 1 hour 41 minutes

I don't care where it tracks I would just like to see it be a little more progressive. Unfortunately if it just spins out there like that it's not going to pull cold air in behind the departing low. Though it does look like the GFS tries to bring some chilly air in east of the Cascades, not like its warm, but more of the same old BS. 

[Gradient Keeper]

Day 6 (4-run trend) Blocking is looking interesting

[fubario]

Not sure if posted...NWS SEA 2pm discussion.

 

.LONG TERM /SATURDAY THROUGH TUESDAY/...A cold upper trough will
move through the area Friday night and Saturday with a frontal
wave bringing an enhanced period of precipitation. Snow levels
will be low and heavier precipitation rates could drive them down
to near sea level. Low level flow will also turn northerly with
some Fraser River leakage. In other words, it looks like lowland
snow is possible again. Generally speaking, ensembles show up to
an inch or two for most areas as the most likely scenario but
there is a good amount of uncertainty with a few members showing
several inches. The best chances for heavy accumulations are over
the Kitsap peninsula and Hood Canal area. The period of main
concern is later Friday night and Saturday morning.

[Omegaraptor]

28 minutes ago, Terreboner said:

Ya, makes sense.  The models probably view the whole area as foothills with no marine influence, nor any rain shadowing due to the higher elevation of the coast range down there.

Being a pretty small rainshadow pocket, not hard to see why models sometimes struggle with it. It is an area where annual rainfall and shadowing can vary drastically over short distances.

[SilverFallsAndrew]

1 minute ago, Omegaraptor said:

Being a pretty small rainshadow pocket, not hard to see why models sometimes struggle with it. It is an area where annual rainfall and shadowing can vary drastically over short distances.

At least it tries to show some shadowing in the Rogue Valley. The Shasta Valley, which is even drier, almost isn't even there.

One of my wife's uncles lives in Weed. Pretty arid there. Her other uncle lives between Weed and Shasta City, just to the SW of Black Butte. It's like a different world. 

[Gradient Keeper]

Day 7 Who ordered the high latitude blocking/ridge bridge? Did you want fries with that?

[SilverFallsAndrew]

The ICON, GFS, and GEM all more or less agree now. The big winner looks to be NORCAL. 

[Slushy Inch]

Need to get that trough out of the ridge, I wonder if we see that feature in GEM and EURO. The number of strong troughs in this outcome is odd.

[Gradient Keeper]

East wind developing

[Gradient Keeper]

Just now, Gradient Keeper said:

East wind developing

6 hours later strong east winds

[Jbolin]

1 hour ago, MossMan said:

KOMO follows the GFS and not the EURO apparently. 

Ok, so I wasn't high as s*** when I saw this tweet earlier.

Good to know

[SilverFallsAndrew]

This run could turn into another fake cold extravaganza. 

[VancouverIslandSouth]

1 minute ago, Gradient Keeper said:

Day 7 Who ordered the high latitude blocking/ridge bridge? Did you want fries with that?

Looks ripe for a "backdoor" blast.

[Gradient Keeper]

Some backdoor cold showing itself

[Gradient Keeper]

Day 7.5 East wind strengthening, significant low level cold intensifying

[Gradient Keeper]

Day 8 Bitter low level cold pool 925s -10c Gorge, Columbia Basin

[Slushy Inch]

Just now, Gradient Keeper said:

Day 8 Bitter low level cold pool 925s -10c Gorge, Columbia Basin

I bet the ridge positions is more favorable in other models and runs.

[Gradient Keeper]

Holy pancakes! 925s -10c to -13c Gorge, Columbia Basin

[SilverFallsAndrew]

Down to 32 now under mostly clear skies, nice to get another freeze in. 6/6 on the month now. 

[Gradient Keeper]

Day 9'er

[Slushy Inch]

Just now, Gradient Keeper said:

Day 9'er

Mother of all retrogrades in progress?

[Slushy Inch]

Meanwhile GEFS moves low father south...

[Gradient Keeper]

Bitter, prodigious low level blast

[Jbolin]

Just now, Gradient Keeper said:

Bitter, prodigious low level blast

Look at you using big words.

[Gradient Keeper]

Just now, Gradient Keeper said:

Bitter, prodigious low level blast

[Omegaraptor]

3 minutes ago, SilverFallsAndrew said:

One of my wife's uncles lives in Weed. Pretty arid there. Her other uncle lives between Weed and Shasta City, just to the SW of Black Butte. It's like a different world. 

Driving I-5 north between Dunsmuir and Weed you lose 2-3" of annual precip per mile. Interesting how sharply it goes from trees to Moses Lake vegetation just north of Weed. Kinda similar to that spot on I-90 between Cle Elum and Ellensburg.

Also interesting how between Ashland and Siskiyou Summit for a few miles the vegetation actually looks like somewhere farther north, with lusher, denser forest and iirc, Douglas Firs being the most common tree. South of Siskiyou Summit it switches over to ponderosa pine and dry scrubland.

[Gradient Keeper]

3 minutes ago, JSnowlin said:

Look at you using big words.

Momma got me a speak-n-spell for my Birfday

[Gradient Keeper]

Day 10

[SouthHillFrosty]

4 minutes ago, 12345WeatherNerd said:

Meanwhile GEFS moves low father south...

[Omegaraptor]

9 minutes ago, Gradient Keeper said:

Holy pancakes! 925s -10c to -13c Gorge, Columbia Basin

Hopefully this is how I am welcomed back to the Portland metro for winter break.

[Gradient Keeper]

850s warm to +10c over PDX while 925s are -12c Gorge, Columbia Basin. Damaging winds east of I-205. Insane winds.

[bishbish777]

1 minute ago, SouthHillFrosty said:

Was about to post the same thing, LOL

[Doinko]

Wow

[Brian_in_Leavenworth]

GEM day 10

 

[Slushy Inch]

Now that's a thing of beauty, look at it extend north of Alaska. 

[SilverFallsAndrew]

My guess at face value is there would be enough of a continental component with this, to avoid the valley being completely socked in with low clouds and fog. BUT if the gradients down the valley go flat it could potentially happen. 

[Gradient Keeper]

What is lying ahead for us is going to be amazing and quite possibly bitterly cold first low level cold pool/inversion, then a bitter regional blast. WOW

[Slushy Inch]

Just now, Gradient Keeper said:

What is lying ahead for us is going to be amazing and quite possibly bitterly cold first low level cold pool/inversion, then a bitter regional blast. WOW

Pretty good agreement among models for a great pattern mid-December! 2008 again please!