January 2021 weather observations for the PNW

[Phil]

Not to mention models (including latest GFS) are projecting another SSW with an impressive mass flux evident (PV technically survived the recent event, albeit highly compromised and in a location that favors further disruption).

[Phil]

8 minutes ago, BLI snowman said:

I'm confident you would have been giving a similar speech at this point in 2008. There was in fact some arctic air that month, the PNW had a modified arctic airmass on the 21st with that offshore block, and then there was a progressive shot of arctic air into B.C. on the 28th.

And if 2007-08 was zonal, what does that make this winter?

No way. +NAM/+NPO w/ equatorward EP fluxes ain’t gonna get the job done under -QBO boundary conditions @ 50mb given -ENSO of that magnitude. How is the NPAC ridge supposed to amplify under those conditions? That’s adjacent to 1974/75 or, at best, 1998/99. But there was a SSW in Dec 1998, unlike 2007/08.

I’d probably give said speech in January 2006. But in hindsight, I can also see where that case diverges too. 

 

[Deweydog]

The number of 384 hour maps being posted seems to have declined slightly.

[BLI snowman]

3 minutes ago, Phil said:

No way. +NAM/+NPO w/ equatorward EP fluxes ain’t gonna get the job done under -QBO boundary conditions @ 50mb given -ENSO of that magnitude. How is the NPAC ridge supposed to amplify under those conditions?

I’d probably give said speech in January 2006. But in hindsight, I can also see where that case diverges too. 

 

But there was NPAC amplification that month, obviously not enough to deliver anything great to the lowlands but enough to deliver a solid and consistent trough wavetrain. Right now, the models employ that same theme.

[BLI snowman]

4 minutes ago, Deweydog said:

The number of 384 hour maps being posted seems to have declined slightly.

AK cold is finally building!

[Phil]

Given the amount of easterly momentum deposited in the subtropics (westerly poleward of that), one could argue the outcome would have mirrored 2007/08 had it not been for the SSW.

It’s a convoluted, sensitive compartmentalization of AAM for sure. And that alone will absolutely screw with model accuracy. Not even accounting for further strat disruptions or the MJO response to an accelerated BDC. 

[SilverFallsAndrew]

Extended GEFS. Maybe we can start building on our meager snow pack here in Oregon. 

Looks like Mt. Hood and the Willamette Basin are down below 70% of average now. 

 

[Phil]

12 minutes ago, BLI snowman said:

But there was NPAC amplification that month, obviously not enough to deliver anything great to the lowlands but enough to deliver a solid and consistent trough wavetrain. Right now, the models employ that same theme.

A broad Aleutian ridge dumping marine polar air into the region isn’t what I would call “amplification”.

Nothing close to continental polar that month.

[MossMan]

Justin and Andrew are not onboard. 
At least I’m still onboard. 

[Kolk1604]

2 minutes ago, MossMan said:

Justin and Andrew are not onboard. 
At least I’m still onboard. 

Phil is that's all that matters

[SalemDuck]

44 minutes ago, Phil said:

Not saying either of these are analogs, but which one bears more resemblance to the projected pattern?

And..what are we missing that will (at least initially) prevent a homogenous outcome in terms of observed weather?

 

Looks a lot more like Jan 1969 to me... also the GEFS are improved and look really good through day 12.

[BLI snowman]

2 minutes ago, Phil said:

A broad Aleutian ridge dumping marine polar air into the region isn’t what I would call “amplification”.

Nothing close to continental polar that month.

Hmm, Spokane had a subzero reading on the 23rd. That doesn't typically happen with marine air....

Interestingly enough Spokane's coldest temp this season is 13. Set on October 25. Their coldest temp since then is 20.

[Phil]

Let’s keep this IO cooling going. 

[SilverFallsAndrew]

4 minutes ago, MossMan said:

Justin and Andrew are not onboard. 
At least I’m still onboard. 

I would not say I am not on board. Onboard for what would be my question? Aside from a few outlier runs, no model has shown arctic air into the PNW. I am totally on board for a cooler 2nd half of the month, perhaps some chilly days, lower snow levels, and the potential for snow below 1000' at times, especially in more favored areas like where you live. But the fact is the ensemble mean at PDX has never gone below -5C, so if we are just looking at what the models are showing and not projecting our fantasies onto them... Overall though I am pretty happy where we are headed. February could be solid, and if we are lucky it gets cold enough next weekend to avoid a top 5 warm January. 

[Phil]

10 minutes ago, BLI snowman said:

Hmm, Spokane had a subzero reading on the 23rd. That doesn't typically happen with marine air....

Interestingly enough Spokane's coldest temp this season is 13. Set on October 25. Their coldest temp since then is 20.

Moving the goalposts east of the cascades now? Why not take it all the way to Bozeman while we’re at it?

And I don’t think anyone would argue this winter hasn’t been zonal *thus far*. The Aleutian low doesn’t die for several more days.

Question is why happens afterwards. You seem to think model guidance has it pegged. I vehemently disagree with that.

 

[SouthHillFrosty]

40 minutes ago, Phil said:

Not to mention models (including latest GFS) are projecting another SSW with an impressive mass flux evident (PV technically survived the recent event, albeit highly compromised and in a location that favors further disruption).

3 SSW?!!!!

[SilverFallsAndrew]

1 minute ago, Phil said:

Moving the goalposts east of the cascades now? Why not take it all the way to Bozeman while we’re at it?

And I don’t think anyone would argue this winter hasn’t been zonal *thus far*. The Aleutian low doesn’t die for several more days.

Question is why happens afterwards. You seem to think model guidance has it pegged. I vehemently disagree with that.

 

A lot of west side locations had lows in the teens with that airmass too... I can attest that does not typically happen during zonal flow events. 

[Phil]

Out of curiosity, what did January 1929 look like out there?

[AlTahoe]

10 minutes ago, SalemDuck said:

Looks a lot more like Jan 1969 to me... also the GEFS are improved and look really good through day 12.

Tahoe snowfall through Jan 1969 170"

This year 32" with most likely 0 for the rest of the month.

When looking at last year as well we are mirroring the Mega drought of 1975-1977 almost perfectly. That was considered a 1 - 500 year drought. But then we had another 1 - 500 year drought 2013-2015. Now we are in the middle of another 1 - 500 year drought 2019-2021.

I would like to think the patter will change in Feb but it looks like no matter what happens the Mega Ridge just keeps getting pumped up over us. Mammoth Mt at 8200' is supposed to hit the mid 60's tomorrow! We are having late April weather this month. 

[Deweydog]

I just got off a conference call with my priest, dentist and hair dresser.  Consensus seems to be that models will look different a week from today.

[BLI snowman]

2 minutes ago, Phil said:

So we’re moving the goalposts east of the cascades now? Why not take it all the way to Bozeman while we’re at it?

And I don’t think anyone would argue this winter hasn’t been zonal *thus far*. The Aleutian low doesn’t die for several more days.

Question is why happens afterwards. You seem to think model guidance has it pegged. I vehemently disagree with that.

 

You called it a marine airmass. That is simply inaccurate. It's been pointed out several times that the PNW had modified arctic/continental air in late January 2008. That stemmed from blocking offshore, albeit not ideal enough to deliver a major blow.

I don't think the models have it pegged at all, but even with perhaps only moderate confidence the signal thus far has been pretty defiantly in favor of a more progressive and/or maritime influence to things after the initial offshore ridge sets up. Aside from a very stray run here or there, there just isn't a whole lot of support for a significant event yet at this juncture. It will definitely turn a lot chillier, that much is a given. 

[Omegaraptor]

3 minutes ago, Phil said:

Out of curiosity, what did January 1929 look like out there?

Portland had 13.2" of snowfall with a mean temp of 34.1F, why?

[SilverFallsAndrew]

4 minutes ago, Phil said:

Out of curiosity, what did January 1929 look like out there?

Really cold with a lot of snow. 

https://climate.usu.edu/mapServer/reports/e15daily.php?stn=USW00024232&year=1929&month=1&unit=EN&network=direct:ghcn&sidebar=0

[Phil]

4 minutes ago, BLI snowman said:

You called it a marine airmass. That is simply inaccurate. It's been pointed out several times that the PNW had modified arctic/continental air in late January 2008. That stemmed from blocking offshore, albeit not ideal enough to deliver a major blow.

I don't think the models have it pegged at all, but even with perhaps only moderate confidence the signal thus far has been pretty defiantly in favor of a more progressive and/or maritime influence to things after the initial offshore ridge sets up. Aside from a very stray run here or there, there just isn't a whole lot of support for a significant event yet at this juncture. It will definitely turn a lot chillier, that much is a given. 

I called it marine polar. That’s the technical definition for what it was.

As you (should) know, it can snow in marine polar air. Ever heard of the Bering sea?

 

[BLI snowman]

6 minutes ago, Phil said:

Out of curiosity, what did January 1929 look like out there?

Pretty different....

[BLI snowman]

Just now, Phil said:

I called it marine polar. That’s the technical definition for what it was.

It can snow in marine polar air. Ever heard of the Bering sea?

 

February 1989 was marine polar as well. The airmass traveled over the Bering Sea to arrive here (from a polar source) and the local boundary layer conditions were no doubt steeped in Pacific influence. Marine polar. Snow.

[Deweydog]

4 minutes ago, Phil said:

I called it marine polar. That’s the technical definition for what it was.

As you (should) know, it can snow in marine polar air. Ever heard of the Bering sea?

 

Not gonna score too many 1 degree dew points (PDX on 1-21-08) around here with any meaningful maritime influence.

[Phil]

1 minute ago, BLI snowman said:

February 1989 was marine polar as well. The airmass traveled over the Bering Sea to arrive here (from a polar source) and the local boundary layer conditions were no doubt steeped in Pacific influence. Marine polar. Snow.

February 1989 had continental polar and marine polar elements. The TPV actually came in from the Yukon, not the Bering Sea.

 

[SouthHillFrosty]

Canadians seem really optimistic moving forward. 

[Phil]

Now we’re comparing January 2008 to February 1989.

Got it. 

[BLI snowman]

Just now, Phil said:

Now we’re comparing January 2008 to February 1989.

Neither was a "marine" airmass by any conventional definition. Gonna just have to admit you were wrong about that and move on.

[AlTahoe]

17 minutes ago, Phil said:

I called it marine polar. That’s the technical definition for what it was.

As you (should) know, it can snow in marine polar air. Ever heard of the Bering sea?

 

To be fair to Phil, Jan 2008 was easily the longest period of dry snowfall storms we have ever had in Tahoe. Snow ratios were 20 to 1 or higher for every storm. The end of the month storms were epic with 1000' snow levels in the foothills of the Sierra. I still have not seen deeper drifts of snow as we had during superbowl weekend that winter. Very unusual for Tahoe. 

[Deweydog]

5 minutes ago, AlTahoe said:

To be fair to Phil, Jan 2008 was easily the longest period of dry snowfall storms we have ever had in Tahoe. Snow ratios were 20 to 1 or higher for every storm. The end of the month storms were epic with 1000' snow levels in the foothills of the Sierra. I still have not seen deeper drifts of snow as we had during superbowl weekend that winter. Very unusual for Tahoe. 

There’s a good chance you guys could do well with the eventual pattern change.

[TigerWoodsLibido]

Looks good!

[AlTahoe]

1 minute ago, Deweydog said:

There’s a good chance you guys could do well with the eventual pattern change.

I hope so. The Operational runs just keep kicking the can down the road and show the same pattern we have seen for over a year and half now. 

[TigerWoodsLibido]

Better than the overnight run

[SouthHillFrosty]

6 minutes ago, TigerWoodsLibido said:

Better than the overnight run

That is a really nice improvement. A lot more snow for the whole western pnw!!

[Jesse]

Sounds like the only thing we are certain about this morning is uncertainty!

[TigerWoodsLibido]

This is far from bad

[OysterPrintout]

Block looking a bit sturdier on the euro 12z