December 2015 in the Pacific Northwest

[Phil]

For anyone interested in watching the PV get bombarded into submission over the next 4 weeks, Levi Cowan's site is a good venue to watch it unfold: http://www.tropicaltidbits.com/analysis/models/?model=gem-ens&region=nhem&pkg=Tz10&runtime=2015122912&fh=24&xpos=0&ypos=110

[Timmy]

I am ready for this airmass to dry up and cool down!  high humidity kills snowpack.  just drove home, sticking snow at about 1300'  so i am right on the line, a lot of snow falling but not building in a hurry, and everything below is foggy and melting fast.

[Phil]

Assuming we complete strat/NAM shake-up by the end of January, there's a good chance resulting equatorial tropopausal height falls/cooling will be sufficient to keep MJO/intraseasonal forcing active, allowing for degradation of Niño as intraseasonal forcing remains decoupled from antecedent SST/inertial component of ENSO.

 

In other words, more prolific strat/NAM shake up = better chance for you guys as tropical forcing can return to MT/WPAC more efficiently w/o NAM/PV preventing NPAC surf zone amplification. However, if ENSO grabs forcing again after first cycle completion, then it's all over for Arctic air west of the Rockies.

[TT-SEA]

I am ready for this airmass to dry up and cool down!  high humidity kills snowpack.  just drove home, sticking snow at about 1300'  so i am right on the line, a lot of snow falling but not building in a hurry, and everything below is foggy and melting fast.

 

 

Yeah... I hate moist air during and after a snowfall.   The Sunday system was great here.   The dewpoints were below freezing and it was not foggy at all.     Then yesterday turned into a mush fest of low clouds and fog.   The air is slowly drying out here now.   The sun is almost out but there is very little melting today.

[MossMan]

Assuming we complete strat/NAM shake-up by the end of January, there's a good chance resulting equatorial tropopausal height falls/cooling will be sufficient to keep MJO/intraseasonal forcing active, allowing for degradation of Niño as intraseasonal forcing remains decoupled from antecedent SST/inertial component of ENSO.

 

In other words, more prolific strat/NAM shake up = better chance for you guys as tropical forcing can return to MT/WPAC more efficiently w/o NAM/PV preventing NPAC surf zone amplification. However, if ENSO grabs forcing again after first cycle completion, then it's all over for Arctic air west of the Rockies.

So no chance for anything good for us until February? 

[luvssnow_spokane]

Assuming we complete strat/NAM shake-up by the end of January, there's a good chance resulting equatorial tropopausal height falls/cooling will be sufficient to keep MJO/intraseasonal forcing active, allowing for degradation of Niño as intraseasonal forcing remains decoupled from antecedent SST/inertial component of ENSO.

 

In other words, more prolific strat/NAM shake up = better chance for you guys as tropical forcing can return to MT/WPAC more efficiently w/o NAM/PV preventing NPAC surf zone amplification. However, if ENSO grabs forcing again after first cycle completion, then it's all over for Arctic air west of the Rockies.

Sounds like this should all start to kick in by spring time... Perfect and right on typical Pacific Northwest schedule...  We can go enjoy a slop-fest in March. YEAH! -- I can barely contain my glee over this and the upcoming inversion. OMG! *snoopy dances*

 

http://www.reactiongifs.com/r/CaogEdw.gif

[Front Ranger]

I don't think three days of modest negative departures will do much to change a 28 day mean. We'll see though.

Like I said, epic torch for the East, but not a coast to coaster.

[Front Ranger]

So no chance for anything good for us until February?

No, in Phil's scenario the best chance for the PNW to get Arctic air is early on. In January.

[luvssnow_spokane]

For anyone interested in watching the PV get bombarded into submission over the next 4 weeks, Levi Cowan's site is a good venue to watch it unfold: http://www.tropicaltidbits.com/analysis/models/?model=gem-ens&region=nhem&pkg=Tz10&runtime=2015122912&fh=24&xpos=0&ypos=110

Yeah, I love this site and have been using it for some time. Thanks for spreading the word as this is a great resource!

[ShawniganLake]

No, in Phil's scenario the best chance for the PNW to get Arctic air is early on. In January.

Maybe late January. That 1-10th period is long dead and buried.

[TT-SEA]

About 20 minutes ago... the clearing line was evident and the Cascades were in the sun.   Now the sun is coming out here.   

 

[Deweydog]

About 20 minutes ago... the clearing line was evident and the Cascades were in the sun. Now the sun is coming out here.

 

Time lapse please!

[MossMan]

About 20 minutes ago... the clearing line was evident and the Cascades were in the sun.   Now the sun is coming out here.   

 

Looks brutal with all of those bare snowless trees.

[Phil]

No, in Phil's scenario the best chance for the PNW to get Arctic air is early on. In January.

Towards the end January, if it occurs, of which I'd give it a 50/50 chance of actually doing so (would be via -EPO/NPAC retrogression).

 

The January 1-10 window was shot in foot by poor timing of NPAC height rises via progression of forcing MT/WPAC, though the predicted amplification/NAM flip is occurring as anticipated.

 

Unusual timing for stagnant IO/MT wave (secondary to stagnant ENSO wave) to decouple from stagnant ENSO wave at this stage in time. However, looking back, this was a bit more than your typical W-IO secondary cell. It was a large standing wave, and in concert w/ EPAC/CPAC ENSO forcing and +QBO thermals/windfield, was able to lock in +PV/+NAM for first half of winter. That was expected, but when intraseasonal propagation of IO wave into MT/WPAC began last week, it was obvious something was up.

[Phil]

Maybe late January. That 1-10th period is long dead and buried.

Yep, I mentioned this last week. Once that stagnant E-IO/W-MT forcing connected w/ export fields aloft/decoupled from low-freq ENSO forcing, it began propagation/morphed into MJO wave.

[ShawniganLake]

Looks brutal with all of those bare snowless trees.

But at least he has perfectly engineered snow banks lining is driveway, allowing for optimal snow preservation.

[TT-SEA]

But at least he has perfectly engineered snow banks lining is driveway, allowing for optimal snow preservation.

Exactly!

[Phil]

Here's a visual depiction of what I'm referring to. Easy to see initiation of IO/W-MT standing wave and the subsequent decoupling. This stagnant forcing regimen was responsible for much of observed NPAC tendencies since the end of October, and is now shifting in response to both typical seasonal progression(s)/response(s) to low-freq ENSO forcing and inertial/resonant effects of +QBO.

 

[ShawniganLake]

Exactly!

I used to do the same thing. I wised up and bought a snow blower, mostly because I occasionally clear snow for work. Doesn't really make for beautiful even snow banks however.

[epiceast]

Snowing moderately here... Pretty surprising that I got most snow today since the storm. All of the other little shower events were a bust for me.

[Phil]

Huge question marks once propagatory process finishes and forcing returns to IO. Does intraseasonal wave propagation continue (systematic degradation of ENSO coupling) or does ENSO grab forcing back (ENSO dominance)?

[Phil]

Yeah, I love this site and have been using it for some time. Thanks for spreading the word as this is a great resource!

You're welcome.

[Phil]

Like I said, epic torch for the East, but not a coast to coaster.

Dude, this was obviously a torch for 90% of the U.S. You're splitting hairs, because no one expected every square inch of the nation to torch.

 

As of now:

[MossMan]

I used to do the same thing. I wised up and bought a snow blower, mostly because I occasionally clear snow for work. Doesn't really make for beautiful even snow banks however.

Wish I would have taken more pictures during the Dec. 08 snows...I had snow banks built up so high at work with the tractor that they stuck around through all of January. They were huge! I did it on propose...don't think my boss was quite as pleased.

[ShawniganLake]

Wish I would have taken more pictures during the Dec. 08 snows...I had snow banks built up so high at work with the tractor that they stuck around through all of January. They were huge! I did it on propose...don't think my boss was quite as pleased.

I was surprised how fast the snow melted in other areas. Snow cover here for the most part lasted through February and into March in shady areas. Snow banks along the driveway lasted well into March and past mid month in some cases. Close to 3 months of snow cover that winter, something I may never see again. Some areas of people's lawns were actually smothered and killed by the snow banks.

[Phil]

Just to highlight, I suspect any blast would occur via NPAC retrogression (SW retrogression of Aleutian low/EPO tank), rather than height rises over Aleutians/WPO domain.

[Bryant]

Assuming we complete strat/NAM shake-up by the end of January, there's a good chance resulting equatorial tropopausal height falls/cooling will be sufficient to keep MJO/intraseasonal forcing active, allowing for degradation of Niño as intraseasonal forcing remains decoupled from antecedent SST/inertial component of ENSO.

 

In other words, more prolific strat/NAM shake up = better chance for you guys as tropical forcing can return to MT/WPAC more efficiently w/o NAM/PV preventing NPAC surf zone amplification. However, if ENSO grabs forcing again after first cycle completion, then it's all over for Arctic air west of the Rockies.

I attempted to say this... Your way just sounds a lot better lol

[Phil]

I attempted to say this... Your way just sounds a lot better lol

Turning incoherent gibberish into coherent gibberish is tough to do. I understood what you were saying perfectly, though.

[Bryant]

Turning incoherent gibberish into coherent gibberish is tough to do. I understood what you were saying perfectly, though.

Talking outside of the forums with you has made me realize it's not gibberish at all, I just never had enough knowledge to understand what you meant

[MossMan]

For anyone interested in watching the PV get bombarded into submission over the next 4 weeks, Levi Cowan's site is a good venue to watch it unfold: http://www.tropicaltidbits.com/analysis/models/?model=gem-ens&region=nhem&pkg=Tz10&runtime=2015122912&fh=24&xpos=0&ypos=110

Awesome link! Will be something to watch during this slow time.

[HighlandExperience]

Snoqualmie pass has now officially recorded the snowiest December on record with over 193 inches.

 

1968 is the second most snowy December!

[Phil]

Talking outside of the forums with you has made me realize it's not gibberish at all, I just never had enough knowledge to understand what you meant

Thanks. I'm also generally not good at explaining all this in laymans terms, though generally speaking there's really no way do it properly without skipping important aspects.

[Front Ranger]

Dude, this was obviously a torch for 90% of the U.S. You're splitting hairs, because no one expected every square inch of the nation to torch.

 

As of now: image.png

Assuming torch is like +3 or higher anomalies, about 2/3 of the US will end up with that. It's not splitting hairs to point out that while the East royally roasted this month, the West did not. We will have substantial areas below normal.

 

Doesn't disprove anything, other than the notion of a coast to coast blowtorch. Those have happened on monthly basis, but not this month.

[Phil]

Around ninety percent of the continental U.S. will finish with an above average December. That warmth will stretch from the PNW to Florida, with huge core of +10 to +15 anomalies over 50% of the nation.

 

How is that not considered a nationwide blowtorch, for all intents and purposes?

[Snowman5678]

Wish I would have taken more pictures during the Dec. 08 snows...I had snow banks built up so high at work with the tractor that they stuck around through all of January. They were huge! I did it on propose...don't think my boss was quite as pleased.

Me too! I have pictures from the first day but none from after that! The snow banks along our driveway were massive. Such an amazing storm!

 

It'll be interesting to see what happens when I'm back in Salt Lake with El Nino...not really sure what to expect. Hopefully not just a massive disgusting inversion. 

[Bryant]

Around ninety percent of the continental U.S. will finish with an above average December (with huge core of +15 anomalies over Great Lakes/NE), and that warmth will stretch from the PNW to Florida.

 

How is that not considered a nationwide blowtorch, for all intents and purposes?

He always seems to pick small fights with you, not sure why

[Front Ranger]

Around ninety percent of the continental U.S. will finish with an above average December (with huge core of +15 anomalies over Great Lakes/NE), and that warmth will stretch from the PNW to Florida.

 

How is that not considered a nationwide blowtorch, for all intents and purposes?

I think your 90% number is too high. And significant portions of those areas will be within a degree of normal. I'll be happy to post the map at the end of the month and show you how it differs from true coast to coasters.

 

I know it seems like it sometimes, but the East is not the whole U.S.

[Front Ranger]

He always seems to pick small fights with you, not sure why

Not picking a fight...he's the one adamantly opposing what I'm saying, not sure why.

 

Am I wrong? Do you think this month will end up as a torch for the West? Just calling it what it is.

[Phil]

He always seems to pick small fights with you, not sure why

I guess he's technically correct that most of the west didn't "blowtorch", but the definition of a conus blowtorch doesn't imply that every region in the country should experience extreme anomalies. That has never happened in recorded history.

 

So yes, he's splitting hairs regarding the definition of the term.

[Deweydog]

Picking nits?