Winter 2014-2015 Thread

[StudentOfClimatology]

I'm hoping the npac ssta's are an insurance policy against an unfavorable persistent vortex making a home. One thing that can make snow weenies cry bloody murder is a Pac air highway with no blocking. We would have plenty of precip chances but the wrong type. Lol.

We haven't had much zonal flow for a while now. 12-13 was loaded with it. I'll have to pull some 500mb plots from the weak nino's we had 8-10 years ago. They were warm here. We got a couple decent storms but the winters on the whole had low # of events and were AN temp wise. I don't remember why though.

From the research I've done/read about, the early mid 1990s were influenced by a number of factors not present at this time, thankfully. For one, the Brewer-Dobson/O^3 flux to the poles was weak, due to the after effects of Pinatubo and CFC-induced depletion..also the Sun was extremely active which further degraded the upward propagating wave train and destroyed whatever O^3 was transported to the poles. In fact, the early/mid 1990s witnessed the highest AP/AA values in recorded history..not good.

So really the only way we could get a legit winter during that era was with a stout -EPO/NPAC ridge (think 1993-94), as there was no way to achieve a sustained -AO. To get that sustained NPAC ridging, a +QBO was required along with weak or negative ENSO, as ridging in the EPO/WPO domain is favored in a +QBO, and is often hard to attain in a Niño as well, as tropical forcings favor Aleutian troughing in that case.

So while I don't think another 1994-95 is in store, I'm a bit worried about the EPO/NPAC being dominated by a vortex, and another pseudo -NAO reminiscent of December 2013, given the QBO and solar state. The key, I think, is keeping solar activity down, and getting Niño 3.4/Niño 4 to warm. Cooling in Niño 1-2 and Niño 3 wouldn't hurt either, in my opinion.

[AlaskaETC]

Wouldn't a vortex like 2013 give us the cool temps to keep us in the snow game?

[Bob Chill]

Wouldn't a vortex like 2013 give us the cool temps to keep us in the snow game?

It's a factor but we rode a thin line much of the time. Ridging just off the east coast was dangerously close. Same setup just a tad west and we rain. What really drove our chances was the strong -epo delivering cold into the upper mw that slid east. No cold shot lasted more than 3 days either. We timed things a lot. Had a lot of vorts slid under us when the lw pattern was favorable. It's just as easy for them to pass just west. Gradient patters at our latitude usually don't work so well. Last year stood out.

We can still have the pv wobbling around Canada and be warm. When we had a -pna/trough west at times last winter we we're warm. That's mostly why December was AOA on the means. Couple 80 degree days didn't help either. lol

[Bob Chill]

From the research I've done/read about, the early mid 1990s were influenced by a number of factors not present at this time, thankfully. For one, the Brewer-Dobson/O^3 flux to the poles was weak, due to the after effects of Pinatubo and CFC-induced depletion..also the Sun was extremely active which further degraded the upward propagating wave train and destroyed whatever O^3 was transported to the poles. In fact, the early/mid 1990s witnessed the highest AP/AA values in recorded history..not good.

So really the only way we could get a legit winter during that era was with a stout -EPO/NPAC ridge (think 1993-94), as there was no way to achieve a sustained -AO. To get that sustained NPAC ridging, a +QBO was required along with weak or negative ENSO, as ridging in the EPO/WPO domain is favored in a +QBO, and is often hard to attain in a Niño as well, as tropical forcings favor Aleutian troughing in that case.

So while I don't think another 1994-95 is in store, I'm a bit worried about the EPO/NPAC being dominated by a vortex, and another pseudo -NAO reminiscent of December 2013, given the QBO and solar state. The key, I think, is keeping solar activity down, and getting Niño 3.4/Niño 4 to warm. Cooling in Niño 1-2 and Niño 3 wouldn't hurt either, in my opinion.

 

 

I'm not sure but I think we got our signals crossed. I was referring to the weak nino's of 04-05 and 06-07. Both were mostly dominated by pac air nearly coast to coast but for different reasons. The short story was we just didn't have much cold air to work with on this side of the globe. 

 

 

 

 

 

Not saying I expect a redux of either. Just taking notes on how weak nino's can be bad and things to look for. 

[StudentOfClimatology]

Ha, I could've sworn I was replying to a post on the 1994-95 Niño. I need sleep.

[Bob Chill]

I'm starting to look at some stuff....I don't think analogs will be that helpful this winter, but what do people think about 79-80..it's been piquing my interest

 

Hey matt! Been awhile. 79-80 huh? Thinking we roast in Dec and freeze in Feb? 

 

Would fit a nino'ish profile. It was a warm neutral year overall but close. Crazy that we're left with hoping a nino materializes after discussing strong vs moderate just a little while ago. 

 

Agree about analogs. Attm there's not much to look at. We probably won't know where we're going until November. I'm just going to hope for a southern storm track to set up. Even if they run west in Dec, any pattern that delivers precip through the southern 3rd can throw bones our way. I really don't have many thoughts yet. Just watching and waiting. 

[HM]

I'm starting to look at some stuff....I don't think analogs will be that helpful this winter, but what do people think about 79-80..it's been piquing my interest

 

Hey man, it's been a while. Anyway, yes, 1979-80 will become a strong analog the weaker this Nino and stronger the sun gets. I'm not sure we'll go as extreme as that year's setup (very powerful Smax like conditions with warm neutral profile/-QBO).

[uncle W]

1979-80?... God forbid... if this year is a weak positive enso winter it would be the first positive enso winter since 2009-10...except for the middle of 1978 it was mostly a weak el nino or nuetral positive from 1976 to 1980...lately we have seen weak negative winters with fake el nino's in the middle of the year...

[GaWx]

 

 

 

I'm not sure but I think we got our signals crossed. I was referring to the weak nino's of 04-05 and 06-07. Both were mostly dominated by pac air nearly coast to coast but for different reasons. The short story was we just didn't have much cold air to work with on this side of the globe. 

 

 Not saying I expect a redux of either. Just taking notes on how weak nino's can be bad and things to look for. 

 

 

 04-05 and 06-07 were very likely warm because of a DJF averaged +NAO per this link:

 

 http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

 

 Note that 2/07, alone, was cold and the NAO had then dropped to -0.47.

  Prospects for a +PDO averaged over DJF seem to be decent as of now. If we actually get that, a weak El Nino fall/winter peak, and a DJF averaged NAO, the chances for quite a cold E Us winter would be well above normal based on history. The toughest part may be getting the -NAO. 

[Isotherm]

While 79-80 was a solar maximum year, solar variables were significantly more intense/higher than right now. Solar flux peaked around 2000-2050 during the winter of 1979-80 coupled with geomagnetic ap index values of between 10-15 consistently.

 

Values right now are about 1400-1450 in terms of solar flux, and a continued low geomagnetic ap index of around 5-10. Most evidence demonstrates the solar maximum has been reached, and we will see a decline in activity over the coming 12 months. The question of course is how quickly will we descend off of Cycle 24's maximum. Will we see relatively strong bursts throughout the winter or will there be a steep drop-off in flux/SSN/geomag for the cold season?

 

The NPAC SSTA does have an influence in terms of creating a positive feedback loop, in my view. The initial causation of the -EPO did not stem from the oceanic pattern but probably Rossby wave activity in the WPAC which enhanced mid-level ridging in the NPAC. This process seems to occur in many pre +ENSO years, such as 1993-94 and 2008-09 for example, two winters with strong -EPOs. Once the El Nino event develops, evidence dictates that we'd see a more neutral/+EPO regime take hold as the Aleutian troughing typical of Ninos tends to push the mid-level ridge into the Western US (forcing more of a +PNA/+EPO rather than the often -PNA/-EPO of last winter). The thing is, the weaker the El Nino event, the higher the probability that we're liable to maintain a -EPO pattern IMO. 1979-80 had a borderline weak Nino/warm neutral and a -EPO. That could be a good ENSO analog depending upon how things transpire this autumn. I wouldn't rule out up to a +1.0c intensity Nino right now.

 

 

Lots of factors to consider as usual. I do believe the Atlantic will be much more favorable this year. I look for more significant clues in October/November but some of the early indicators suggest a less positive NAO than last winter.

[Quixotic1]

Hey man, it's been a while. Anyway, yes, 1979-80 will become a strong analog the weaker this Nino and stronger the sun gets. I'm not sure we'll go as extreme as that year's setup (very powerful Smax like conditions with warm neutral profile/-QBO).

Wouldn't 79-80 be a poor analog considering the overall background state? We've been in the Nina/nada thing for over four years now. 76-77, 77-78 were weak Ninos......just a thought.

[frosty]

Solar flux was very low recently which I think is very telling. Solar activity has been

low to very low for over a month now and apart from sporadic upticks I think we will see

a continued downward trend in activity from here on.

I must admit to being quite upbeat for this winter here in England. It certainly will not be

anything like the nightmare of a winter we had last year. Not one flake of snow through

December/March.

[mitchnick]

I know it's early and can change fast, but arctic sea ice has been looking good for a while.

[Deck Pic]

Hey matt! Been awhile. 79-80 huh? Thinking we roast in Dec and freeze in Feb? 

 

Would fit a nino'ish profile. It was a warm neutral year overall but close. Crazy that we're left with hoping a nino materializes after discussing strong vs moderate just a little while ago. 

 

Agree about analogs. Attm there's not much to look at. We probably won't know where we're going until November. I'm just going to hope for a southern storm track to set up. Even if they run west in Dec, any pattern that delivers precip through the southern 3rd can throw bones our way. I really don't have many thoughts yet. Just watching and waiting. 

 

Hey dude!.....I don't know how useful a backyard analog 79-80 would be ....It was a very convoluted, changeable pattern, once we got past Christmas...And it wasn't like 2004-05 or 2006-07, when we knew we were screwed until Mid to late January....we shook the bad PAC early enough to make most of winter interesting....

 

Hey man, it's been a while. Anyway, yes, 1979-80 will become a strong analog the weaker this Nino and stronger the sun gets. I'm not sure we'll go as extreme as that year's setup (very powerful Smax like conditions with warm neutral profile/-QBO).

 

Hey man!  I've become more interested in the patterns of the 79-82 period as I am just starting to look at stuff again...I'd become too rigid in my thinking, and my huge bust last winter is forcing me to re-examine things and think outside the box more than I have been...I was completely blindsided by how much southern stream influence we had in January/February

 

Wouldn't 79-80 be a poor analog considering the overall background state? We've been in the Nina/nada thing for over four years now. 76-77, 77-78 were weak Ninos......just a thought.

 

It's a very reasonable thought.....There was a lot of Nina influence still lingering last winter, and it took a very impressive EPO anomaly to push the pattern just south and east enough and with enough cold air that we were able to take advantage.....even with a formidable southern stream, most of the time we have a strong vortex to our NW and a ridge to our east, we are going to get screwed a lot...Unless we get a real deal nino, I don't think we are going to get as nino-esque a pattern as 79-80.... a persistent blocking pattern would solve a lot as long as we have a cold air source, regardless of what the rest of the pattern is like..

[wildweatherman179]

Hey dude!.....I don't know how useful a backyard analog 79-80 would be ....It was a very convoluted, changeable pattern, once we got past Christmas...And it wasn't like 2004-05 or 2006-07, when we knew we were screwed until Mid to late January....we shook the bad PAC early enough to make most of winter interesting....

Hey man! I've become more interested in the patterns of the 79-82 period as I am just starting to look at stuff again...I'd become too rigid in my thinking, and my huge bust last winter is forcing me to re-examine things and think outside the box more than I have been...I was completely blindsided by how much southern stream influence we had in January/February

It's a very reasonable thought.....There was a lot of Nina influence still lingering last winter, and it took a very impressive EPO anomaly to push the pattern just south and east enough and with enough cold air that we were able to take advantage.....even with a formidable southern stream, most of the time we have a strong vortex to our NW and a ridge to our east, we are going to get screwed a lot...Unless we get a real deal nino, I don't think we are going to get as nino-esque a pattern as 79-80.... a persistent blocking pattern would solve a lot as long as we have a cold air source, regardless of what the rest of the pattern is like..

So out of curiosity, are you thinking the troughing may shift west as we enter the early fall?

[Deck Pic]

So out of curiosity, are you thinking the troughing may shift west as we enter the early fall?

 

I don't know...I just started looking at this winter and haven't even paid attention to fall....If we don't get a nino, I imagine we will have some semblance of a southeast ridge again this winter

[wildweatherman179]

I don't know...I just started looking at this winter and haven't even paid attention to fall....If we don't get a nino, I imagine we will have some semblance of a southeast ridge again this winter

Got ya. I was pretty well thinking the same thing unless some blocking develops in which case I think the PV may be strong enough to overcome a ridge down there. That's a big "if" though. I usually don't look at winter too much this time of year either but last winter left me looking forward to the upcoming winter. I look at fall as well because it really sets the stage for winter in a lot of ways. I'm really excited about this year based on what I see and have studied so far. Not sure about the Niño yet. Not really considering it a driver for the winter months though. Should get quite a few cut off systems through the south with the warmth off the coast of Mexico and Cali also. Just my thoughts so far.

[Bob Chill]

Latest enso discussion is about as expected considering what has been happening the last month or 2. 

 

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf

 

 

Over the last month, model forecasts have slightly delayed the El Niño onset, with most models 

now indicating the onset during July-September, with the event continuing into early 2015 (Fig. 6). A

strong El Niño is not favored in any of the ensemble averages, and slightly more models call for a weak 

event rather than a moderate event. At this time, the consensus of forecasters expects El Niño to emerge 

during August-October and to peak at weak strength during the late fall and early winter (3-month values 

of the Niño-3.4 index between 0.5°C and 0.9°C). The chance of El Niño has decreased to about 65% 

during the Northern Hemisphere fall and early winter (click CPC/IRI consensus forecast for the chance of 

each outcome).

 

 

Other than the obvious weaker than expected event being possible, the fact that the onset/peak is moving forward in time also causes some cloudiness in trying to guess what's in store this season. 

 

A weaker event to possibly non-event is becoming pretty likely attm but still time to change. Going with the latest guidance opens the door for other smaller scale factors to drive the patterns. Smaller scale stuff has limited lead time so there's nothing to really discuss for a while. 

 

The siberian snow cover stuff in Oct will probably be the first longer lead indicator we'll have to work with other than enso. But even then the ao defied the index and went negative in Jan and most of Feb. It did rage + in Dec though. It would go a long ways towards a  decent winter with the NAO being active. It doesn't need to be negative all season or anything. We do well during phase changes. Especially flipping - to +. It's been a while there but there are plenty of recent multi year runs with the nao not helping at all. The 90's were down right terrible in that respect. 

 

As always, a couple of things that can make us cry is a poorly placed vortex in the npac with a -pna and a dreaded poorly place se ridge without blocking to the N. But these aren't things we can really worry about until they actually happen or become likely to happen. 

 

Would love to see a solid -1.00 or lower AO setup in Dec. That is one thing that usually has legs for a 30-45 day period and can also be a precursor to a winter dominated by an overall -ao (bleeding into Jan at the very least). I've said this a few times over the years but for those who don't remember, Wes did a scatter plot of 4"+ snows for our area and the single most important index for greatly increasing the odds is a -ao. If you have to root for single oscillation, that is surely the one for us down here south of 40. 

 

IMO- we're probably at equal odds of a crappy, climo, or +climo snow year until things start to become more clear in late oct through nov. Even then, long lead stuff is full of pitfalls and caveats. For me, it's a whole lotta scope and hope for the next 3 months, 

 

 

 

 

[mitchnick]

Bob, apparently the Euro's latest winter forecast (a day or 2 ago) came out looking like 02/03 and 09/10 per Bastardi

 

http://www.americanwx.com/bb/index.php/topic/43733-2014-2015-winter-outlooks-and-discussions/?p=3026008

[AlaskaETC]

Bob, apparently the Euro's latest winter forecast (a day or 2 ago) came out looking like 02/03 and 09/10 per Bastardi

 

http://www.americanwx.com/bb/index.php/topic/43733-2014-2015-winter-outlooks-and-discussions/?p=3026008

 

Anyone with ECMWF access verify?

[Bob Chill]

Bob, apparently the Euro's latest winter forecast (a day or 2 ago) came out looking like 02/03 and 09/10 per Bastardi

http://www.americanwx.com/bb/index.php/topic/43733-2014-2015-winter-outlooks-and-discussions/?p=3026008

I tend to avoid contemplating really long lead model stuff. Do you really believe that it's possible for skill and accuracy worth buying into at leads like that? I sure don't. 15 day ensembles flop around. Euro weeklies are maybe worth discussing ideas. Seasonals have proven time and time again to add little value and more conflicting ideas.

Euro thought we were going mod/strong Nino 10 weeks ago. Heh

[mitchnick]

I tend to avoid contemplating really long lead model stuff. Do you really believe that it's possible for skill and accuracy worth buying into at leads like that? I sure don't. 15 day ensembles flop around. Euro weeklies are maybe worth discussing ideas. Seasonals have proven time and time again to add little value and more conflicting ideas.

Euro thought we were going mod/strong Nino 10 weeks ago. Heh

well, I look at it this way....if I want a model to show a decent winter LR, the Euro is the one we want

hence, it's worth mentioning imho

another positive in my weenie mind is that the CFS2 forecast for August in MAR was at or above normal in the east and, as we all know, it has turned seriously cooler (the hope being the model is running too warm)

like I said earlier, I'm optimistic        

[WEATHER53]

Getting more excited every minute.

[hosj III]

https://epawaweather.com/2014/08/early-look-into-the-signals-of-the-winter-of-2014-2015/

 

EPAWA's thoughts.

 

We are not really in their coverage area, but its a good read nonetheless. 

[Jebman]

Larry Cosgrove mentioned the possibility of a Pineapple Express this upcoming winter in one of his recent newsletters.

[AlaskaETC]

Larry Cosgrove mentioned the possibility of a Pineapple Express this upcoming winter in one of his recent newsletters.

Good for us?

[Jebman]

Pineapple Express will bury the Rockies in many, many meters of snow. It will also help alleviate Lake Mead's drought.

 

Pineapple Express also would introduce a lot of Pacific air into the lower 48.

[AlaskaETC]

Pineapple Express will bury the Rockies in many, many meters of snow. It will also help alleviate Lake Mead's drought.

Pineapple Express also would introduce a lot of Pacific air into the lower 48.

Well....that would suck.

But didn't a Pineapple Express happen last year too? I'm assuming with a solid +PDO/vortex displacement, that it wouldn't matter too much?

[North Balti Zen]

Or, Pineapple Express would introduce moisture and storms track to our liking. 2009-10 wasn't frigid, but was snowy.

[mitchnick]

I just hope the CFS2 is incorrect with the placement of an upper level trough south of the Gulf of Alaska which floods NA with warm air. We're sunk if it is right. It would be almost the exact opposite of what we've been having. What worries me, however, is that the Ridge over AK has got to break down at some point, soooooo......