December 2014 Observations for the Pacific Northwest

[Snowman5678]

We did.

 

The upper levels were really only cold Saturday and Sunday but your snow probably did not melt till Thursday right?

 

Oh yeah we did...Wow I forgot already. Last week was super busy so I didn't get to pay attention to the weather and what was catually going on very much.

[Bedonbye]

Wait I just read Richard's tl;dr. Did I just see the word "academically" in there? *rubs eyes* Indeed.

what do you want? I came to this forum cause I love the Weather! its so unpredictable that is what I love. know one is never 100% accurate, however I always felt that I was different from others cause I was obsessed with the Weather. here I found a web site with People that love the Weather like me. I wish everyone could just get along. its about the love of the Weather!

[HighlandExperience]

I think we need some cold & snow to make people feel happy again. 

[stuffradio]

There's a special weather statement for up here for 4-8" of rain by mid to end of the week.

[bainbridgekid]

Thursday looking pretty breezy for the Oregon Coast.

 

http://www.atmos.washington.edu/mm5rt/data/current_extended/images_d2/slp.90.0000.gif

[Phil]

Again, I feel like I can't spend a day, let alone a meal away.

#ElNiño

[MossMan]

Thursday looking pretty breezy for the Oregon Coast.

 

http://www.atmos.washington.edu/mm5rt/data/current_extended/images_d2/slp.90.0000.gif

Maybe it will track north and we could get in on a nice windstorm!

[Phil]

Uh oh..moving into a -AO/-EPO/-NAO even before we obliterate the PV in early Jan?

 

Tropical forcing should progress sufficiently to drop the PNA in January..only then we'll be in the middle of a SSW/-TAM and the wave train will be longer..

 

This entire block should consolidate N/NW and strengthen in January, IMO..

 

http://catchmypicture.com/f/8nZHUB/640.jpg

[ShawniganLake]

Uh oh..moving into a -AO/-EPO/-NAO even before we obliterate the PV in early Jan?

 

Tropical forcing should progress sufficiently to drop the PNA in January..only then we'll be in the middle of a SSW/-TAM and the wave train will be longer..

 

This entire block should consolidate N/NW and strengthen in January, IMO..

 

http://catchmypicture.com/f/8nZHUB/640.jpg

uh oh?

 

That sounds good, or am I missing something.

[stuffradio]

Uh oh..moving into a -AO/-EPO/-NAO even before we obliterate the PV in early Jan?

 

Tropical forcing should progress sufficiently to drop the PNA in January..only then we'll be in the middle of a SSW/-TAM and the wave train will be longer..

 

This entire block should consolidate N/NW and strengthen in January, IMO..

 

http://catchmypicture.com/f/8nZHUB/640.jpg

I assume that means a massive West coast ridge. Am I right?

 

In other news, Cliffmass wrote a new blog entry. He specifically mentions good news for those who like eating CA vegetables. This is for those who want references. http://cliffmass.blogspot.ca/2014/12/when-is-normal-not-normal-and-coming.html

 

Edit: I guess it doesn't mean a massive ridge, because you're talking about a tanking PNA.

[luvssnow_spokane]

Uh oh..moving into a -AO/-EPO/-NAO even before we obliterate the PV in early Jan?

 

Tropical forcing should progress sufficiently to drop the PNA in January..only then we'll be in the middle of a SSW/-TAM and the wave train will be longer..

 

This entire block should consolidate N/NW and strengthen in January, IMO..

 

http://catchmypicture.com/f/8nZHUB/640.jpg

Could u kindly please elaborate? What does this mean for us? It does not sound good!

[Deweydog]

Good lord...

[Phil]

The "uh oh" was supposed to be sarcastic. That -EPO ridge tends to retrograde under a wave-1 stratosphere..

 

The central/eastern US will get it first, followed by the western US later on, if everything comes together properly..still thinking early or mid January?

[Phil]

Good lord...

I was second-guessing my sanity there for a bit

[stuffradio]

Ok, so I learned something new from a different site. I was only using PNA before as a tool for ridging, but a -EPO is also coupled with a ridge in the Gulf of Alaska.

 

Edit: I assume that was a -EPO that was partially to blame or thanked for our cold snap we just had.

[Deweydog]

I was second-guessing my sanity there for a bit

 

You seem like a sharp enough guy, but you always seem to forget.  You need to be explicit, especially after December 1st when every weenie's biological clock begins to tick louder and louder.  

[IbrChris]

The "uh oh" was supposed to be sarcastic. That -EPO ridge tends to retrograde under a wave-1 stratosphere..

 

The central/eastern US will get it first, followed by the western US later on, if everything comes together properly..still thinking early or mid January?

January could be, but December looks like a nice torch out west and even across the central US at least through part of the 11-15 day period. I like the chances for renewed cold east toward Christmas though and probably continuing through New Years. I'm thinking rather similar to what they saw earlier in Nov in terms of the overall long wave pattern. There are subtle hints of high latitude ridge retrogression into a more favorable spot (Alaska/Yukon) for a larger cold dump into the lower 48 toward the end of Dec/very early Jan but I think this will largely slide east of the Rockies. Until we see ridging reestablish in the N Pacific between 150 W and the Date Line we are looking at W-SW flow and often splitty at that.

[Skagit Weather]

It's going to be wet!

[Skagit Weather]

The next couple days should put me over 2012's rain total here making this the wettest year I have recorded. 1.2" to go.

55/47 today.

[ShawniganLake]

Less than 2 weeks until the days start getting longer. It's getting close to panic time.

[stuffradio]

Less than 2 weeks until the days start getting longer. It's getting close to panic time.

Panic! At the disco.

[Phil]

January could be, but December looks like a nice torch out west and even across the central US at least through part of the 11-15 day period. I like the chances for renewed cold east toward Christmas though and probably continuing through New Years. I'm thinking rather similar to what they saw earlier in Nov in terms of the overall long wave pattern. There are subtle hints of high latitude ridge retrogression into a more favorable spot (Alaska/Yukon) for a larger cold dump into the lower 48 toward the end of Dec/very early Jan but I think this will largely slide east of the Rockies. Until we see ridging reestablish in the N Pacific between 150 W and the Date Line we are looking at W-SW flow and often splitty at that.

Agreed on December.

 

The one thing to note is that the PV is progged to transition from its barotropic state into a more baroclinic state in the week-2 & week-3 period, while developing a westward tilt with height. That is going to leave it extremely vulnerable to the upcoming round of breakers, and I suspect that major SSW will result sometime around New Years under a favorable tropical forcing. On the ECMWF dataset, this all looks very similar to the SSW events in 1968-69, 1979-80, and 2012-13..with some similarity to 2006-07 as well: http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

 

Also, the BDC has been feeling the effects of the Niño & -QBO for some time now..it's raging. These factors all point to an increased likelyhood of both a complete SSW cycle, and perhaps a tropical response. Nice paper by Resmi et al on this: http://www.sciencedirect.com/science/article/pii/S1364682613001946

[stuffradio]

Agreed on December.

 

The one thing to note is that the PV is progged to transition from its barotropic state into a more baroclinic state in the week-2 & week-3 period, while developing a westward tilt with height. That is going to leave it extremely vulnerable to the upcoming round of breakers, and I suspect that major SSW will result sometime around New Years under a favorable tropical forcing. On the ECMWF dataset, this all looks very similar to the SSW events in 1968-69, 1979-80, and 2012-13..with some similarity to 2006-07 as well: http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

 

Also, the BDC has been feeling the effects of the Niño & -QBO for some time now..it's raging. These factors all point to an increased likelyhood of both a complete SSW cycle, and perhaps a tropical response. Nice paper by Resmi et al on this: http://www.sciencedirect.com/science/article/pii/S1364682613001946

Just so people don't ask, BDC = Brewer Dobson Circulation.

[IbrChris]

Agreed on December.

 

The one thing to note is that the PV is progged to transition from its barotropic state into a more baroclinic state in the week-2 & week-3 period, while developing a westward tilt with height. That is going to leave it extremely vulnerable to the upcoming round of breakers, and I suspect that major SSW will result sometime around New Years under a favorable tropical forcing. On the ECMWF dataset, this all looks very similar to the SSW events in 1968-69, 1979-80, and 2012-13..with some similarity to 2006-07 as well: http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

 

Also, the BDC has been feeling the effects of the Niño & -QBO for some time now..it's raging. These factors all point to an increased likelyhood of both a complete SSW cycle, and perhaps a tropical response. Nice paper by Resmi et al on this: http://www.sciencedirect.com/science/article/pii/S1364682613001946

SSW around New Years suggests a fragmented PV (meridional flow with several daughter vortices) toward mid Jan. Hard to say where they dig but I wouldn't be so cavalier about the N-central PAC trough breaking down or even retrograding to a favorable position since the long wave pattern seems to me at least to be a feedback of the emerging, intensifying El Niño. In other words I see it wobbling at best over the next month maybe longer. No substantive hint of retrogression on Euro Weeklies IMO. I think east of the Rockies may see an impressive arctic blast in January although probably not the magnitude of last January.

[Phil]

SSW around New Years suggests a fragmented PV (meridional flow with several daughter vortices) toward mid Jan. Hard to say where they dig but I wouldn't be so cavalier about the N-central PAC trough breaking down or even retrograding to a favorable position since the long wave pattern seems to me at least to be a feedback of the emerging, intensifying El Niño. In other words I see it wobbling at best over the next month maybe longer. No substantive hint of retrogression on Euro Weeklies IMO. I think east of the Rockies may see an impressive arctic blast in January although probably not the magnitude of last January.

I guess you're thinking that El Niño will be dominating the tropics for the foreseeable future? If anything I'm seeing El Niño losing it's grip, based on both a low Walker/Hadley intensity ratio and the loss of low-frequency EPAC forcing since mid-November..

 

http://catchmypicture.com/f/8V9eP0/640.jpg

 

http://catchmypicture.com/mPQkP2.jpg

 

I don't anticipate the NPAC troughing will disappear, but I suspect it will weaken and retrograde west in January..enough to qualify as a -PNA? The tropics often respond starkly to the SSW cycle..2012-13 being the latest example of this..only then it was the resulting MJO wave battling with a stronger Walker Cell, so I'm not sure it'll go down quite like that this time? We don't have that strong Walker Cell to slow/amplify the wave..

[snow_wizard]

Agreed on December.

 

The one thing to note is that the PV is progged to transition from its barotropic state into a more baroclinic state in the week-2 & week-3 period, while developing a westward tilt with height. That is going to leave it extremely vulnerable to the upcoming round of breakers, and I suspect that major SSW will result sometime around New Years under a favorable tropical forcing. On the ECMWF dataset, this all looks very similar to the SSW events in 1968-69, 1979-80, and 2012-13..with some similarity to 2006-07 as well: http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

 

Also, the BDC has been feeling the effects of the Niño & -QBO for some time now..it's raging. These factors all point to an increased likelyhood of both a complete SSW cycle, and perhaps a tropical response. Nice paper by Resmi et al on this: http://www.sciencedirect.com/science/article/pii/S1364682613001946

Those analogs would suggest some fun times for us.

 

I am in total agreement with your timing based on entirely different criteria than you use.

[snow_wizard]

Less than 2 weeks until the days start getting longer. It's getting close to panic time.

In reality the coldest part of the winter historically speaking is mid January. Lots of time for some goodies.

[snow_wizard]

Frikken amazing how many days 1979 and 2006 have been showing up as analogs now with a good showing from 2003 also. All warm ENSO winters that delivered nicely in early January. Probably something to it...

[IbrChris]

Phil I am not ruling out retrogression but I don't think it's the favored solution at this point. I typically refrain from speculating beyond about 2-3 weeks out because more often than not it's too easy to miss subtleties in the 2 week pattern evolution that completely rule out a hypothetical month-ahead evolution. I do think ENSO will be the dominant teleconnection as we get later into winter although I believe it will remain fairly modest in its effects. That's not to say we won't get cold at some point in Jan/Feb although I'll leave that speculation to other folks on the forum.

[Phil]

I respect your views and appreciate the discussion. There's a reason the 3-6 week period is often called "no mans land" in sub-seasonal forecasting.

 

It's been my goal to break through that barrier for awhile now.

[primetime]

Uh oh..moving into a -AO/-EPO/-NAO even before we obliterate the PV in early Jan?

 

Tropical forcing should progress sufficiently to drop the PNA in January..only then we'll be in the middle of a SSW/-TAM and the wave train will be longer..

 

This entire block should consolidate N/NW and strengthen in January, IMO..

 

Phil - when you say tropical forcing, just wondering what this is based on...MJO, CCKW, VP Anomaly progression?  What are you looking at to know the tropical progression?

[Tyler Mode]

36 this morning here in Battle Ground.  Incredibly boring weather the last few days, but it's nice to take a break from the models etc.

[Tyler Mode]

Not the most colorful sunrise, but the clouds were interesting:

http://weathercrazy.smugmug.com/Landscapes/Winter-20142015

[Jesse]

Great mountain snow pattern on the long range 12z.

[stuffradio]

I like the long range around Christmas.

[SilverFallsAndrew]

The 12z GFS gives me a few minor snow threats in the LR. I am skeptical that the pattern shown would really play out like that. I have a feeling it will trend a little splittier as the timing movies up.

[SilverFallsAndrew]

Great mountain snow pattern on the long range 12z.

 

I hope I'm wrong, but the way the pattern sets up in the long range I think it trends more toward a split flow with most of the energy diving south and with the less consolidated jet probably not quite as cool as the 12z shows. I think at some point and hopefully this month we get some decent mountain snows. Even in December 2002 we had a couple decent storms hit the NW that got the ski areas open. 

[Tyler Mode]

12z GFS shows strong winds for the Oregon coast with a strong but weakening and baggy low.  Gradient never lines up for the valley, but we shall see. 

[Tyler Mode]

Then there's this...

12z GFS shows strong winds for the Oregon coast with a strong but weakening and baggy low.  Gradient never lines up for the valley, but we shall see. 

 

[MR.SNOWMIZER]

Great mountain snow pattern on the long range 12z.

Need that bad. Olympics up here are bare almost.