December 2019 Weather Discussion for the PNW

[snow_wizard]

Going forward the thing to watch for at the very end of the month is going to be how flat or amplified the ridge just off the coast ends up being depicted on the models.  A flatter ridge can more easily lead to a good outcome as upstream high pressure cells can more easily piggy back onto the flat ridge.  We want that cold air in AK to remain until a GOA ridge can amplify enough to drive it toward us.

[snow_wizard]

00z Euro showed almost a half inch of snow falling from Snohomish County northward Christmas morning and a skiff in the EPSL. Best run yet for that.

 

Not expecting much, if anything, but still. Something to watch and at this point I'd gladly take just seeing some snow fall in the air.

 

The little cold snap next week has certainly become more impressive over the past couple of days.  850s are -5 or so for about 5 days now on the latest runs.  Around the same time 1936 started to get interesting as well.

[snow_wizard]

A. Nice to see you back

 

B. Isn’t the SE ridge a bit of a downstream response anyway. If the ridge amplified and the trough dug into the west, then the SE ridge would likely show up.

 

Indeed.  The lower heights being shown over the SE are a left over artifact from a departing trough.

[snow_wizard]

We all just can't/don't extrapolate as well as you apparently. When we see models and ensembles keep puking over themselves, what do you expect? You and Culverjosh are the only people who say the goods will happen soon with zero evidence.

 

The models have actually been all over the place taking turns on showing something good trying to happen.  Typical behavior before a major event.  The table is set for a great winter.

[snow_wizard]

Night shift is back!

 

That is one way you can tell things are on the uptick.  If this latest improvement on the EPS is for real we will see some great model improvements over the next couple of days.

[snow_wizard]

I'm curious what Phil's thoughts are on this.  Looks like a strat warming might be starting.

 

[Cloud]

Yep. BIG improvement in fact. Block/positive anomaly is further west in the sweet spot. The cold isn't dumping out off Alaska into the Gulf of Alaska. Heights in BC/AB dramatically lower than previous runs. No deep trough carving out over the eastern half of the country. There is some amplification noted with the block, we just need more of it and tilt. Of course a southeast ridge always helps. Interesting how the Day 11-15 EPS mean and Control run are mirroring each other. My optimism is building.

 

Good to see you back!

[Kayla]

[MossMan]

Currently 35 chilly degrees.

[MR.SNOWMIZER]

Nobody does a Christmas song like Burl Ives.

[MossMan]

Nobody does a Christmas song like Burl Ives.

Or Stan Boreson!!

[Omegaraptor]

 

 

Today’s sunrise at Timberline Lodge

[TacomaWaWx]

Im hopeful that the LR maps verify and lead to snow...but that is still a long ways out. Id like to see possible cold coming down the pipeline sooner before building up my excitement. I have some hope that this winter will deliver though.

[Deweydog]

Pretty amazing model improvement.

[TacomaWaWx]

Down to 39 degrees in Tacoma this morning...pretty foggy here.

[FroYoBro]

Pretty amazing model improvement.

 

In what way?

[TacomaWaWx]

In what way?

You never know if hes serious...lol.

[Deweydog]

In what way?

. I thought I was the only one who couldn’t see it so I thought I’d just jump on board to sound smartly.

[TT-SEA]

You never know if hes serious...lol.

He is not serious.

 

Have you looked at the 12Z GFS for later this week?

[FroYoBro]

s**t. I thought I was the only one who couldn’t see it so I thought I’d just jump on board to sound smartly.

 

I thought you were pretending to be Tim or something. Those storms that were showing up a few days ago sure got destroyed. 

 

 

Looks dry. 

[TacomaWaWx]

He is not serious.

 

Have you looked at the 12Z GFS for later this week?

Im pretty sure everyone has...thats why its quiet this morning.

[FroYoBro]

Time to go back to a very boring pattern. 

[MR.SNOWMIZER]

In what way?

Green horn.

[snow_wizard]

The 12z is much flatter with the offshore ridge around New Years Eve and the AK PV is much more west than previous runs.  Good stuff!

[Guest CulverJosh]

Looks like above average temps in Alaska and the Yukon around that timeframe as well.

 

Anchorage 10 day forecast should trend warmer.

[MR.SNOWMIZER]

462 heights are impressive in western Canada.

[HighlandExperience]

We all just can't/don't extrapolate as well as you apparently. When we see models and ensembles keep puking over themselves, what do you expect? You and Culverjosh are the only people who say the goods will happen soon with zero evidence.

I wouldn’t compare sno wizard to culver. Seems insulting.

[Guest CulverJosh]

I wouldn’t compare sno wizard to culver. Seems insulting.

I’m just hoping the fireworks on New Years Eve don’t warm up the upper levels too much to where we only get sleet.

[Phil]

This is the 850mb temp anomaly map for the control model. That actually shows the AK cold dropping toward us and already here to some extent. The change in the mean was pretty dramatic so it's pretty exciting.

I doubt any cold outbreak will come from AK this year without a SSW to release the TPV.

 

If this were Niña/+QBO it’d be another story, but to drive the cold south of the border this time you probably want a ridge up in Alaska.

 

Also, if you look at the individual members of the EPS, the ones with the strongest Alaskan vortex are the warmest in the PNW, and vice versa. So it’s deceptive.

[ShawniganLake]

I’m just hoping the fireworks on New Years Eve don’t warm up the upper levels too much to where we only get sleet.

Looks like my new snowblower is going to be sitting idle for awhile. No thanks to your “fishing buddy.”

[Jesse]

I’m just hoping the fireworks on New Years Eve don’t warm up the upper levels too much to where we only get sleet.

What happened to your NWS buddy. Or are none of us even pretending to not think that was a complete lie anymore.

[Guest CulverJosh]

What happened to your NWS buddy. Or are none of us even pretending to not think that was a complete lie anymore.

He is on vacation but he never told me anything has changed. And theoretically the back end of the AR hasn’t exited the region yet so let’s see how it plays out.

[Phil]

The 12z is much flatter with the offshore ridge around New Years Eve and the AK PV is much more west than previous runs. Good stuff!

Is this sarcasm?

 

That’s the exact opposite of what you guys want to see.

[Jesse]

He is on vacation but he never told me anything has changed. And theoretically the back end of the AR hasn’t exited the region yet so let’s see how it plays out.

This definitely sounds pretty dense.

[Guest CulverJosh]

This definitely sounds pretty dense.

Yes, 65 at Timberline, 34 in Portland, dense.

[snow_wizard]

462 heights are impressive in western Canada.

 

The cold in AK and the Yukon is ridiculous on this run.  Talk about potential!  This run is a giant step in the right direction.

[Phil]

The 12z GFS demonstrates the inherent challenge of amplifying a +EPO regime containing the TPV. Usually the attempts at amplification will send the cold air way east until the vortex frays and surf can dislodge it.

 

As long as the TPV itself is in/north of Alaska there is little chance of cold making it south of the border, unfortunately. Most of it will be hurled off to the east.

[snow_wizard]

Is this sarcasm?

 

That’s the exact opposite of what you guys want to see.

 

The flatter ridge at that point leads to a better outcome.  I've seen It many times before.

[snow_wizard]

The 12z GFS demonstrates the inherent challenge of amplifying a +EPO regime containing the TPV. Usually the attempts at amplification will send the cold air way east until the vortex frays and surf can dislodge it.

 

As long as the TPV itself is in/north of Alaska there is little chance of cold making it south of the border. Most of it will slide east.

 

Tell that to Feb 1989.  No doubt this thing has super potential to go good for us.  Earlier runs tapped into the cold and dumped into the East.  This run some of it makes it down this way.

[Phil]

The flatter ridge at that point leads to a better outcome. I've seen It many times before.

Such as? Was the TPV located in the Beaufort Sea?

 

Hard to see anything happening until said TPV disintegrates or departs the western Arctic.