December 2023 Weather in the PNW

[Rubus Leucodermis]

GFS is no longer the only model showing a little lowland snow in the clown range.

[Gradient Keeper]

I was out earlier, so couldn't run the 00z's tonight. I can post re-caps if you'd like? Okay sure.

00z GFS re-cap. 10 Day GIFs: 500mb Height Anomaly, 850mb Temps, 1000-500mb Thickness/MSLP/Precip

A surprisingly decent run. Yeah. Day 1-6. It will be wet. Very wet. Sort of wet. Then wet again. Air mass cools nicely after the AR for some mountain snow. Day 6+ Strong ridge building and this allows a decent cold shot to sneak back into eastern Washington and through the Gorge. This results in strong east winds, probably the strongest of the fall season. The pattern progression Day 4.5 to 7 does seem rather plausible, so maybe this pans out. Day 8+ an active pattern may resume long range.

[Rubus Leucodermis]

22 minutes ago, SnowWillarrive said:

Will need high temps in the teens for two weeks in order to offset this warmth. 

There will be highs in the teens this winter.

In degrees Celsius.

[Perturbed Member]

These temps are just wrong and pretty sad for the time of year. 

Already missing our fake cold from last week and looking at all the Christmas lights with the heavy frost everywhere.

[Phil]

18 minutes ago, MR.SNOWMIZER said:

Fukin tired of this . 

El Niño/+IOD in the drivers seat.

[Gradient Keeper]

00z GFS 7 Day Rainfall, Snowfall totals

[Gradient Keeper]

00z ECMWF re-cap. 10 Day GIFs: 500mb Height Anomaly, 850mb Temps, 1000-500mb Thickness/MSLP/Precip

This run also was rather interesting. A bit wetter than the GFS. There is some suggestion that we could see very low snow levels Saturday morning, but I'm not buying it. Strong ridge builds offshore oriented slightly different, so the cold air sliding south out of Canada only gives us a glancing blow. It still results in several days gusty to strong east wind. Long range is more uncertain with a ridge lingering over us. If only that ridge were not so transitory and anchored itself offshore. Although not likely should that occur much colder air could possibly spill back into eastern Washington. Maybe something to keep an eye on. This looks like a classic Columbia Basin cold pool pattern as well.

[Gradient Keeper]

00z ECMWF 7-Day Rainfall, Snowfall totals

[Deweydog]

Pretty crazy how orographically-dependent this system is. The east side hasn’t even mixed out yet despite the raging SW’erly flow.

[Gradient Keeper]

1 minute ago, Deweydog said:

Pretty crazy how orographically-dependent this system is. The east side hasn’t even mixed out yet despite the raging SW’erly flow.

The warm sector has been extremely impressive.

6z GFS in 1 hour 23 minutes

[snow_wizard]

33 minutes ago, SnowWillarrive said:

Will need high temps in the teens for two weeks in order to offset this warmth. 

We're only talking a couple of days of warmth like this.  One day with a high in the teens would offset a few days like this.  We just finished a pretty chilly November.

[snow_wizard]

1 minute ago, Gradient Keeper said:

The warm sector has been extremely impressive.

6z GFS in 1 hour 23 minutes

Stuff like this in the winter very often leads to cold later.  Very 1990 ish vibe.  That year has been coming up in the analogs quite a bit.

[Front Ranger]

2 minutes ago, snow_wizard said:

We're only talking a couple of days of warmth like this.  One day with a high in the teens would offset a few days like this.  We just finished a pretty chilly November.

Phil's been talking about near constant warmth for the CONUS recently, but the last couple weeks were actually pretty chilly for the majority of the nation. And it looks like once we get through the next few days, that may resume.

[Deweydog]

1 minute ago, snow_wizard said:

Stuff like this in the winter very often leads to cold later.  Very 1990 ish vibe.  That year has been coming up in the analogs quite a bit.

Massive -PNA wave breakapalooza ain’t happening this year, but I suspect the end of this month is gonna be fake and fabulous.

[Tanis Leach]

I question whether PDX will get down below 60 tonight. 

[SnowySeeker50]

Currently 57f and light rain. High of 62 and .84" total for yesterday

[ShawniganLake]

2.5” here yesterday and 0.12” since midnight.  

[Meatyorologist]

1 minute ago, Deweydog said:

Massive -PNA wave breakapalooza ain’t happening this year, but I suspect the end of this month is gonna be fake and fabulous.

I can see it now... a subfreezing high on Christmas for KSEA with freezing fog reported during all hours of the day, with the exception of all hours after 8pm due to a damaging buildup of rime ice. A broad 602dam ridge sits centered right over Jesse's house. Paradise hits 76F.

Andrew's residence happens to spire a couple hundred feet above the inversion and kisses 81F amidst a roaring east wind and a sweeping view of the stratus sea below. He is also high enough to hear god laugh.

[Deweydog]

8 minutes ago, Meatyorologist said:

I can see it now... a subfreezing high on Christmas for KSEA with freezing fog reported during all hours of the day, with the exception of all hours after 8pm due to a damaging buildup of rime ice. A broad 602dam ridge sits centered right over Jesse's house. Paradise hits 76F.

Andrew's residence happens to spire a couple hundred feet above the inversion and kisses 81F amidst a roaring east wind and a sweeping view of the stratus sea below. He is also high enough to hear god laugh.

And somehow Randy will end up with 14” of snow.

[Meatyorologist]

3 minutes ago, Deweydog said:

And somehow Randy will end up with 14” of snow.

All inversion snizzle

[Cold Snap]

Managed to get 1.22” of rain today. Picked up another 0.15” since midnight. Already up to 2.55” for the month so far.

[TigerWoodsLibido]

57F and cloudy. Hot start to December.

[SnowySeeker50]

https://twitter.com/NWSSeattle/status/1731964695077347578?s=20

 

[TigerWoodsLibido]

Looks like a pretty uniform low 60s December nightmare at most of the Willamette Valley stations right now. Was yesterday like a +20F burger departure?

[SnowySeeker50]

[Gradient Keeper]

Current PWAT

[Gradient Keeper]

Night Shift 6z GFS, Day 6 back that ridge a bit and we see a real cold shot into eastern Washington.

[FroYoBro]

Crazy that pdx hit 67. The rain has finally arrived here and it’s already pouring hard. Should be some impressive totals for the day around Portland. 

[SilverFallsAndrew]

11 minutes ago, FroYoBro said:

Crazy that pdx hit 67. The rain has finally arrived here and it’s already pouring hard. Should be some impressive totals for the day around Portland. 

Jeez 

[Tyler Mode]

Hit 64 after 11 PM last night, very impressive.  Already over a half inch of rain today here.

[Ken in Wood Village]

Be careful when driving to work. There is a lot of standing water on the roadways. If you are taking i-84 in, there is an accident. Be careful. 

 

[TacomaWx]

Have been here for 26 hours now treating water…lol 

[Requiem]

Looks like the Grays is at major flood stage already-- with more rain to come over the next 12 hours 

[T-Town]

1.29 yesterday and .79 since midnight. 58 degrees. 

[T-Town]

I have to drive to Seattle this morning. Thoughts and prayers accepted. 

[SnarkyGoblin]

34 minutes ago, TacomaWx said:

Have been here for 26 hours now treating water…lol 

Is that....legal?

[Rubus Leucodermis]

0.51" since midnight, 3.31" storm total. 50.0˚F.

5.46" for the month so far.

[TT-SEA]

Looks like its going to go right back to drier than normal.  This the 10-day anomaly starting that period tomorrow morning (days 1-11).   December 2015 stayed wet for most of the month.  

[Tyler Mode]

1.01" so far today.

[Tyler Mode]

Love the rain shadow on the Olympic peninsula.

Closing in on 4" month to date at my house.