December 2019 Weather Discussion for the PNW

[FroYoBro]

It was a map and comment Andrew had posted earlier.  "For 6 hours. Then it lifts the cold air north as a low develops offshore".  This happens to us a lot closer to the Cascades.  We'll have cold air in place and when a low develops and starts moving some moisture in, we get a layer of warmer air sandwiched in in the mid levels and kills our snow. 

 

The eastern warm nose isn't really happening in a pattern like that. That warm nose shows up more in an overrunning event with warmer air mixing down. 

[Prairiedog]

Ah so the big January 5th Portland snow event everyone’s been buzzing about. Glad we are finally starting to nail down the surface details.

Yep, got screwed here.  My mother in law near Mt Scott got crushed(18").  I had rain until 4am before it finally changed over and I got a measly 4". 

[Front Ranger]

January 2008 redux. Meaningful amplification is sorely lacking right now.

Looks more promising than that to me.

 

Jan 2012 is easily attainable. Jan 2007 is not far out of reach...

[SilverFallsAndrew]

Was looking forward to opening day at Hoodoo today, but my wife decided to stay in bed til...Well she's not even up yet. At this point may just need to leave her at home. 

[Jesse]

The eastern warm nose isn't really happening in a pattern like that. That warm nose shows up more in an overrunning event with warmer air mixing down.

 

Yeah that isn’t a classic warm nose pattern. That’s more like southerly winds for everyone down here.

[Deweydog]

Josh?

[MossMan]

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

That is lovely!

[Phil]

There’s still some residual AK/Yukon vortex and W-IO forcing during the *early portion* of January. Arctic air..even maritime polar air might be tough to come by at first as models struggle to handle the transition away from the old +IOD background state into the new IPWP/WPAC driven one. The Pacific subtropics/Hadley Cell are also expanded again via QBO/+PMM/extended IPWP coupling..also favors the slower transition with the poleward anticyclones and rossby wave dispersion.

 

As the month progresses, it’s my belief that the WPAC will take over and GOA/AK ridging will come to dominate the pattern, increasing the likelyhood of Arctic intrusion into the PNW and west-central US in general. So while it might initially be easier for cold to stay bottled up and/or slide east at the start of January, with time there should be more meridional action IMO.

[SilverFallsAndrew]

Looks more promising than that to me.

 

Jan 2012 is easily attainable. Jan 2007 is not far out of reach...

 

Maybe for singular events. January 2008 was a pretty cool month overall though. I would be disappointed if this coming January is not cooler than 2012. 

[Prairiedog]

The eastern warm nose isn't really happening in a pattern like that. That warm nose shows up more in an overrunning event with warmer air mixing down. 

I agree, I was being a bit negative.  I haven't done well the last several years compared to folks west of me.  I'm at about 310ft but just maybe 15 miles from the foothills south of Sandy.  I get shafted here no matter what happens. 

[TigerWoodsLibido]

 

Mean stays below 0 after Jan 4.  Looking good.

[Gradient Keeper]

I sure hope the Euro saves the day pinching the energy off as the 00z/EPS showed last night. It could just be me, but I don't like any of the trends on the 12z GFS, GEFS, GEM. Luckily it's only one run. On the runs this morning cold air only dumps out over the ocean. No changes there. Colder onshore flow only = cold rain. Nice snow for the Mountains. Boring. I hate to be a buzzkill, but this isn't cold/arctic air working its way south down through BC into the Columbia Basin which is what we want to see. When the 12z GFS Ensembles mean temp is colder for Portland than Yakima that's not what we want to see. Going forward we must see amplification and higher heights over southern Alaska/Anchorage around 550-560dm+. I suppose there's always the chance of low coming in to the south if the polar jet is suppressed. There is still plenty of time for models to come around to a more favorable 500mb pattern.

 

Euro running now!

[Front Ranger]

Maybe for singular events. January 2008 was a pretty cool month overall though. I would be disappointed if this coming January is not cooler than 2012.

I meant the actual events most people care about, not the months overall.

 

It is, after all, still 4 days away from January.

[Prairiedog]

Warm noses  are indeed more with overriding events.  I've just had trouble geting much of the good stuff.  Last Christmas many in SE Portland area had a great snow storm.  Wind and blowing snow along I-205 and towards Gresham.  Got to drive in it headed to family in Vancouver.  It was a winter wonderland.   I had a trace of grauple at our place. 

[Deweydog]

I sure hope the Euro saves the day pinching the energy off as the 00z/EPS showed last night. It could just be me, but I don't like any of the trends on the 12z GFS, GEFS, GEM. Luckily it's only one run. On the runs this morning cold air only dumps out over the ocean. No changes there. Colder onshore flow only = cold rain. Nice snow for the Mountains. Boring. I hate to be a buzzkill, but this isn't cold/arctic air working its way south down through BC into the Columbia Basin which is what we want to see. When the 12z GFS Ensembles mean temp is colder for Portland than Yakima that's not what we want to see. Going forward we must see amplification and higher heights over southern Alaska/Anchorage around 550-560dm+. I suppose there's always the chance of low coming in to the south if the polar jet is suppressed. There is still plenty of time for models to come around to a more favorable 500mb pattern.

 

Euro running now!

BTW, that’s Jim outside screaming and pounding on your door. Don’t open it and call 911.

[Deweydog]

Warm noses are indeed more with overriding events. I've just had trouble geting much of the good stuff. Last Christmas many in SE Portland area had a great snow storm. Wind and blowing snow along I-205 and towards Gresham. Got to drive in it headed to family in Vancouver. It was a winter wonderland. I had a trace of grauple at our place.

Same thing happened this Christmas too.

[Jesse]

BTW, Jim outside screaming and pounding on your door. Don’t open it and call 911.

 

Jim would probably agree with everything Rob said. He's certainly not as awesome/unfairly persecuted as Tim, but the guy is no dummy!

[Phil]

[Phil]

Would be nice if the delete button wasn’t right next to the edit button.

[Gradient Keeper]

12z ECMWF Day 2

 

[Jesse]

Would be nice if the delete button wasn’t right next to the edit button.

 

I have made that mistake on several occasions, especially when on my phone.

[Gradient Keeper]

Day 3

 

[Front Ranger]

12z ECMWF Day 2

 

Very nice!!

[jakeinthevalley]

Cold onshore flow is generally just really modified Arctic air.

I'll be willing to wager that all air has been tropical or arctic at some point in it's existence.

 

Change my mind.

[Deweydog]

I'll be willing to wager that all air has been tropical or arctic at some point in it's existence.

 

Change my mind.

If the air could talk!

[Gradient Keeper]

Day 4

 

[jakeinthevalley]

If the air could talk!

You can hear it if you truly BELIEVE. (kinda like a jingle bell)

[Gradient Keeper]

00z GEFS last night super tanked the PNA

 

[Gradient Keeper]

Day 5

 

 

[Phil]

Looks like a paper worth reading. Will dig in tonight. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL085592

 

Of course these can overlap, but that goes without saying.

 

[Gradient Keeper]

Day 6

 

[Phil]

I think 12z Euro is better than 00z for D7-10 potential. Retracted TPV, better NPAC ridge axis.

[Gradient Keeper]

Day 7

 

[Phil]

There’s a better moat between TPV over Greenland and the trough over the Yukon/W-Canada this run.

 

If there’s going to be a vortex present, at least this way its influence isn’t detrimental.

[Jesse]

Euro looks front loaded.

[GHweatherChris]

Some lowland snow in Western WA a week from today.

 

Can you show all of Western Washington please?

[Phil]

Euro looks front loaded.

Not sure if this is an inside joke, but this run will almost certainly bleed more cold into the region D7-10 vs 00z.

[Gradient Keeper]

Euro leads the way. Still 3 days of model runs to go before I feel that cut-off/Kona situation is nailed down. We need to see the block slide east near 155 W with that degree of tilt. Cold onshore flow is not exciting.

[HighlandExperience]

Some lowland snow in Western WA a week from today.

 

 

 

Snowier runs ahead. Someone post the wxbell snow map. They look prettier. 

[Deweydog]

Not sure if this is an inside joke, but this run will almost certainly bleed more cold into the region D7-10 vs 00z.

The other Phil just said it won’t cold any time soon.