December 2019 Weather Discussion for the PNW

[Gradient Keeper]

I think it's more a testament to how hard up people around here are for any worthwhile weather when there's actually been this much hubbub over some cool onshore flow in the 8+ day range. Nothing great has ever been in view.

Yep, exactly. Chilly onshore flow is nothing anyone should be excited about. Until we see models/ensembles come to an agreement for a kona low, block, and building heights at least 540dm(560+ preferred) over southern Alaska/Anchorage, everyone should consider going into a Winter coma and stay in bed.

 

00z NAM in 2 hours 33 minutes

[Jesse]

Yep, exactly. Chilly onshore flow is nothing anyone should be excited about. Until we see models/ensembles come to an agreement for a kona low, block, and building heights at least 540dm(560+ preferred) over southern Alaska/Anchorage, everyone should consider going into a Winter coma and stay in bed.

 

00z NAM in 2 hours 33 minutes

Given how this ridgy/splitty cold season has gone so far, chilly onshore flow is definitely worth getting excited about. I like it when the mountains get snow, and it is sorely needed.

[MossMan]

What the hell am I going to do with all of this now that winter is officially cancelled?

[Randyc321]

I usually can tell 2 weeks out if we are going to get a cold snap because my hemorrhoids start acting up. Well it's been bad for the last two days. I'm locking it in.

 

 

This might be an ANALog.  When did they act up last?

[TigerWoodsLibido]

Just the usual.  Get the interesting weather to the 7-8 day mark and the rug gets pulled.  Like 90% of the time.

[Gradient Keeper]

Given how this ridgy/splitty cold season has gone so far, chilly onshore flow is definitely worth getting excited about. I like it when the mountains get snow, and it is sorely needed.

Well sure in the sense that we're receiving moisture and mountain snows, I get that, but in terms of anything further than that.... I don't see what there is to be excited about. The 12z EPS after Day 12 shows potential. The 12z CMCE 500mb pattern was pretty D**n good. The EPS PNA, EPO forecast looks very encouraging.

 

00z EPS in 8 hours 47 minutes (Tidbits)

[AbbyJr]

Why do forecasts change? Meteorologist Tyler Hamilton has the answer. This is very interesting and explains why we often see dramatic model shifts run to run in the long range.

 

https://www.theweathernetwork.com/news/articles/why-your-long-range-forecast-changes-how-long-range-models-work-ask-the-meteorologist/119654

[SilverFallsAndrew]

FWIW the models have trended much cooler in the January 1-3rd range. Good for some decent mountain snow. This is the coldest ensemble run yet for the 4th. 

[Dave]

I can't wait for the 18z ensembles to finish us off. Those tissues will come in handy.

[Esquimalt]

The op is a complete warm outlier

[TigerWoodsLibido]

Operational is the warmest member in the mid range (which of course means it will be correct).

[BLI snowman]

For some perspective, there's been very little cold air recently anywhere on a global scale. Europe and Asia have been massively torching.

 

We really need a strong -ENSO response at this point to shake up the system.

[Gradient Keeper]

Tons and tons of mountain snows, so where as I'm not excited, it's nice to see that.

[ShawniganLake]

Ensembles actually look okay. If not a touch better

[Weiner Warrior]

Last February

 

This might be an ANALog. When did they act up last?

[TigerWoodsLibido]

Ensembles are still fine in the believable range.  No cliff jumping yet.

[Timmy]

The op is a huge warm outlier after next weekend

[MossMan]

The op is a complete warm outlier

Great to hear!

[Jesse]

Well sure in the sense that we're receiving moisture and mountain snows, I get that, but in terms of anything further than that.... I don't see what there is to be excited about. The 12z EPS after Day 12 shows potential. The 12z CMCE 500mb pattern was pretty d**n good. The EPS PNA, EPO forecast looks very encouraging.

 

00z EPS in 8 hours 47 minutes (Tidbits)

Yes, from a purely lowland perspective, probably not exactly thrilling unless you enjoy cold rain like I do. I agree that the long range still holds some potential.

[SilverFallsAndrew]

For some perspective, there's been very little cold air recently anywhere on a global scale. Europe and Asia have been massively torching.

 

We really need a strong -ENSO response at this point to shake up the system.

 

Hopefully we can slip into a Nina for next winter. Some of the recent ENSO forecasts have moved in that direction, though as Phil mentioned the other day they can be wildly inaccurate. 

[Gradient Keeper]

Just need amplification bit more tilt and we'll be building snowmen forever and ever.

[TigerWoodsLibido]

Up to 48F.  Let's see if we hit 50F.

[The Swamp]

welp, i would be happy with a three week period of heavy mountain snow

[MossMan]

Just need amplification bit more tilt and we'll be building snowmen forever and ever.

Which the models tonight could very well show.

[Gradient Keeper]

Hey, hey! Yakima ensembles shows a signal for backdoor colder air around January 11th-13th. EPS also showed that. 500mb pattern a bit better. Hmmm!

 

[BLI snowman]

Hopefully we can slip into a Nino for next winter. Some of the recent ENSO forecasts have moved in that direction, though as Phil mentioned the other day they can be wildly inaccurate. 

 

A full fledged Nino next winter followed by a healthy Nina in 2021-22 would probably be our best realistic outcome if we're talking strictly ENSO.

[jakeinthevalley]

It's like being an Oklahoma fan. Last night, optimism was high. Today, reality hits.

[Farmboy]

I can't wait for the 18z ensembles to finish us off. Those tissues will come in handy.

Why wait? Here's a fork to go with the tissues.

[Gradient Keeper]

18z GFS Ensembles

The persistent signal for the pattern change January 3rd continues to show for many days now. That is unchanged. Wet, TONS of Mountain snows. WOW! Potential for colder temps long range.

 

Portland

http://old.wetterzentrale.de/pics/MT8_Portland_Oregon_USA_ens.png

 

 

Seattle

http://old.wetterzentrale.de/pics/MT8_Seattle_USA_ens.png

 

 

Vancouver BC

http://old.wetterzentrale.de/pics/MT8_Vancouver_Kanada_ens.png

 

 

Yakima

http://old.wetterzentrale.de/pics/MT8_Yakima_USA_ens.png

[SilverFallsAndrew]

I really like the trend in the January 1-3rd time period. Could see some good rain and snow amounts. 

[Gradient Keeper]

Baby steps. Toddler trots. Preschooler Prances

[SilverFallsAndrew]

Listen up because I am only going to say this once. FWIW, the ensembles look a lot like they did in late January last year. A solid negative departure, but nothing that really jumped out at you. We all know how that turned out...Not to say we will see a repeat, but that was not a late December 2016 situation where we had runs showing -12C 850mb temps, etc... 

[TigerWoodsLibido]

Maybe we can squeeze in a sub-40F day on Jan 4? 

 

[Dave]

The new year will start off being a solid mud producer.

[GHweatherChris]

Listen up because I am only going to say this once. FWIW, the ensembles look a lot like they did in late January last year. A solid negative departure, but nothing that really jumped out at you. We all know how that turned out...Not to say we will see a repeat, but that was not a late December 2016 situation where we had runs showing -12C 850mb temps, etc...

Don't threaten us!

[SilverFallsAndrew]

44/32 today. 

[Jesse]

18z ensembles were really quite good if you are looking for a wetter, more active pattern with mountain snows in the short to mid range, followed by long range potential.

[Gradient Keeper]

What we know: Solid ensemble agreement for pattern change on January 3rd. That's in just 5 1/2 days. Timing has moved forward instead of pushing everything back as we so often see. Massive supply of cold air to our north. PNA, EPO to be heavily in our favor. Looking at Day 5 to 6 we are quite close to seeing a ridge merger take place and if that happens along with a kona low we'll go into an arctic pattern quickly. No sign of split flow. Doing jumping jacks make me fart. Frosty the Snowman smokes meth in his pipe that's what makes him magically come alive and dance around. The story claims its his hat, but we know better than that. Santa might not be real. Epstein didn't kill himself

 

What we don't know: Heading through the first two weeks of January do we just see cold onshore flow that progressively turns colder enough for snow to 500' and to the valley floor at times with slushy accumulations. Do snow levels remain 1000-2000'+. Do we see a historic January with snow and reloads. Will Tim and Andrew be snowed in. Who killed Epstein.

[Esquimalt]

18z ensembles were really quite good if you are looking for a wetter, more active pattern with mountain snows in the short to mid range, followed by long range potential.

The new snow depth ensembles look pretty amazing for Vic

[MossMan]

Call me crazy...But the ensembles continue to improve as the operational gets worse...interesting. Oh and I am working on something that will either make for a full winter go...or winter cancel...Stay tuned!