Winter 2014-2015 Pattern Discussion Thread I

[Met1985]

A couple of things I took from that...if he is correct and there is a SSW in early January then things would get interesting in mid/late January.  Things could still be fine before then as GaWx pointed out the other day, we don't need a SSW but I would think we would still need atleast a weakened PV.

 

Hence, we see a lower probability of a SSW for December than anticipated in previous postings We anticipate that the polar low will eventually slide off to the south and east allowing for the Siberian High to expand and recommence vertical wave propagation.

 

We continue to anticipate that the vertical wave propagation will resume in mid- to late December and become anomalously strong, for reasons discussed above. This should result in a significant if not major SSW, consistent with the high October Eurasian snow cover paradigm. Therefore, the prospects for a SSW in early January are still highly probable

Good analysis man. We will just have to see how things propagate heading towards the end of December.

[griteater]

Pattern on the overnight ensembles was ugly for as far as the eye can see

 

On the strat stuff, most of what I read is still very optimistic, though I have been following the Cohen blog as well.

 

One of the correlations to monitor in November is 70mb temperatures in eastern Siberia (especially in the 2nd half of Nov).  Above normal temperatures (warm stratosphere) in this region correlates to a -AO for Dec/Jan (averaged), while below normal temperatures (cold stratosphere) correlates to a +AO.  The correlation breaks down for Feb.  I first saw it posted by skierinvermont a few years ago, and there has been talk of it this fall in the New England region.

 

As seen below, this correlation looks good for a Dec/Jan averaged -AO

 

 

[deltadog03]

I could see us having to sacrifice December, MOST** of it.  Not all.  Either way, I would rather punt for DEC and have a rocking JAN/FEB  no offense to anyone, but DEC is great, but JAN and FEB *and hell even MAR* have more potential for most. 

[Snowless in Carrollton]

I could see us having to sacrifice December, MOST** of it. Not all. Either way, I would rather punt for DEC and have a rocking JAN/FEB no offense to anyone, but DEC is great, but JAN and FEB *and hell even MAR* have more potential for most.

I completely disagree. I would much rather have a rocking Dec than Jan or Feb. There's just something about cold and snow around Christmas time that makes it seem more magical.

[oconeexman]

I could see us having to sacrifice December, MOST** of it. Not all. Either way, I would rather punt for DEC and have a rocking JAN/FEB no offense to anyone, but DEC is great, but JAN and FEB *and hell even MAR* have more potential for most.

I'm with you! January is much better in the upstate.

[GaWx]

I could see us having to sacrifice December, MOST** of it.  Not all.  Either way, I would rather punt for DEC and have a rocking JAN/FEB  no offense to anyone, but DEC is great, but JAN and FEB *and hell even MAR* have more potential for most. 

 

 Instead, of me reposting my latest thoughts about Cohen's work, I'll just link it here:

 

 http://www.americanwx.com/bb/index.php/topic/45015-interview-with-judah-cohen/?p=3163172

 

 Note that I focus on the animation at the bottom of Cohen's 1/25/14 update. Hint: it is very encouraging. As a matter of fact, a mild dominated 12/1-20 would ironically be encouraging rather than discouraging as regards overall DJF cold chances. His work actually favors mild then!

 

 Also, fwiw, one of my top analogs, 1939-40, was warm dominated during the period 12/1-19/1939.

[NorthernUpstateSC]

The biggest snow I have ever seen here in south carolina was the first week of January 1988. This was right after a very warm couple of weeks the last of december. Shorts and t-shirts was the theme for that christmas day. We had just over 16 inches of snow from that storm and it stayed on parts of the ground for the entire month of January. One of the coldest January's followed that storm. So, I would not get to discouraged if it is mild up until christmas or just after.

[mackerel_sky]

Per GSP , that high in the NE area is going to be 1045 MB ,that's going to give us the wedge on Tuesday ! Too bad we don't have blocking to keep it into place, but keep them sliding down and we will get the timing right this winter!

[Webberweather53]

I could see us having to sacrifice December, MOST** of it.  Not all.  Either way, I would rather punt for DEC and have a rocking JAN/FEB  no offense to anyone, but DEC is great, but JAN and FEB *and hell even MAR* have more potential for most. 

 

Hi all, I've been a lurker on the forums for the last few years & thanks to Chris mentioning what was being said about winter here, I finally decided to join in on the fun. I completely agree with you Chris, that's how I have felt about this winter for the last few months. I know you've already seen this graphic, but I'll post it here as well. +ENSO intensity & standardized US monthly winter temps in .2 STD increments using 1981-2010 climatology. (I could have used 1951-2010 climo, but I think the high SAI/SCE along w/ other conditions will likely bias our observed temperatures on the cold side of the ENSO composites...)

Warm Neutral Years: 1960-61, 1979-80, 1990-91, 1992-93, 1993-94, 2003-04

Weak El Nino Years: 1952-53, 1953-54, 1958-59, 1969-70, 1976-77, 1977-78, 2004-05, 2006-07

Moderate El Nino Years: 1951-52, 1963-64, 1968-69, 1986-87, 1991-92, 1994-95, 2002-03, 2009-10

Strong El Nino Years: 1957-58, 1965-66, 1972-73, 1982-83, 1987-88, 1997-98

It's amazing to see no matter what intensity +ENSO you choose, February in many cases is not only cold, but often the coldest month of the winter in the southeastern US... I also threw together another composite, while trying to squish as many ENs as I could into it & it also shows the same general trends for the southeastern US. Dec is meh, Jan is at least pretty good, Feb is awesome...

 

 

 

This cold/snowy trend in Feb is also evident in general on the eastern seaboard if you look at NESIS snowstorms. In a Warm Neutral/El Nino state, Feb has more winter storms than every other month of winter combined... 

 

Most major model guidance, the Euro Ensembles included, are going straight for that classic December El Nino look in the 11-15, warmth to the north & west, cooler south & east.

 

 

 

As far as I'm concerned, the clock is ticking on the upcoming pattern flip, eastward MJO progression through the Pacific = decreasing NAO/AO & throwing in the recurvature of 95W in the Western Pacific, we could be in business in the 2nd half of December...

 

 

& I'm personally not buying how the model guidance is trying to punt the MJO into the COD in the long range given the weakened Walker Cell & eastward displacement of the West Pacific Warm pool, which if anything, argues for the MJO to continue on w/ amplitude through this portion of the global tropics. The fact that the bias correction of the GFS/ECMWF has more amplitude in the Pacific next week should be a huge clue. I can't even begin to count the number of times I've seen the models pull this garbage in the long range trying to throw the MJO back into the COD way too quickly...

[Webberweather53]

This Global SST pattern is pretty much a dead give away IMO for a predominantly -AO this winter, cool SSTs like that in both the Atlantic & Pacific ~40N weakens the natural geopotential height & temperature gradient between the subtropics & the high latitudes= weaker polar night jet and the East QBO is only adding insult to injury, IMO...

 

The semblance between the regressed 500mb for November in yrs w/ a strong N hem October snowpack is interesting, (aside of course from the persistent polar low over northwestern Asia Cohen mentioned) because if you extrapolate that 500mb pattern through the rest of winter, it looks like eye candy... If this were to somehow verify, Feb still looks like the most fun, IMO.

 

 

 

 

On the other hand, I'm still trying to contemplate a viable physical mechanism, but I have noticed a weak correlation between the return period of multi year El Ninos/warm ENSO events & the following El Nino Winter's AO. Generally, the more time between multi year events, the better the odds for -AO, and this year would easily fit into the subset of El Ninos w/ a -AO...

[Met1985]

Great stats webber and welcome to the board.

[deltadog03]

 Instead, of me reposting my latest thoughts about Cohen's work, I'll just link it here:

 

 http://www.americanwx.com/bb/index.php/topic/45015-interview-with-judah-cohen/?p=3163172

 

 Note that I focus on the animation at the bottom of Cohen's 1/25/14 update. Hint: it is very encouraging. As a matter of fact, a mild dominated 12/1-20 would ironically be encouraging rather than discouraging as regards overall DJF cold chances. His work actually favors mild then!

 

 Also, fwiw, one of my top analogs, 1939-40, was warm dominated during the period 12/1-19/1939.

Thanks for that Larry!  I fully agree!!

[deltadog03]

Great stats webber and welcome to the board.

Not gonna lie, he is a smart dude!!  @webberweather on twitter.  no FB he said Twitter is enough..hahaha

[deltadog03]

This Global SST pattern is pretty much a dead give away IMO for a predominantly -AO this winter, cool SSTs like that in both the Atlantic & Pacific ~40N weakens the natural geopotential height & temperature gradient between the subtropics & the high latitudes= weaker polar night jet and the East QBO is only adding insult to injury, IMO...

 

The semblance between the regressed 500mb for November in yrs w/ a strong N hem October snowpack is interesting, (aside of course from the persistent polar low over northwestern Asia Cohen mentioned) because if you extrapolate that 500mb pattern through the rest of winter, it looks like eye candy... If this were to somehow verify, Feb still looks like the most fun, IMO.

 

 

 

 

On the other hand, I'm still trying to contemplate a viable physical mechanism, but I have noticed a weak correlation between the return period of multi year El Ninos/warm ENSO events & the following El Nino Winter's AO. Generally, the more time between multi year events, the better the odds for -AO, and this year would easily fit into the subset of El Ninos w/ a -AO...

PERFECT post, thank you sir!

[deltadog03]

Thanks Eric, @webberweather for the bode of confidence.  I love the weather, and this is a great site.  Y'all can follow me on twitter @wxmanchris    and on my new FB page at:    https://www.facebook.com/pages/Wxmanchris/690966551001476?ref=hl    Thanks everyone!  I really do appreciate it.  spread the word, share the pages, and if you want invite your friends.  Not just your typical twitter and FB pages either.  We like to have fun, post pics/videos...etc.  I do try to put them on air as well.  -Chris 

[tnweathernut]

Thanks for your input Webberwx. Very well laid out. Please post more .......

[Hvward]

Nice info webber! That's how you introduce yourself to the forum!

[FallsLake]

Thanks Webber! Nice to have another smart person on board.

[FallsLake]

Definitely looking like we'll have a warmer pattern for the next couple of weeks. But even in a warmer pattern there is always hope. The 18z GFS shows something interesting at day 10. This will most likely not occur as depicted, but just saying to not totally give up on the first half of December.

 

http://mag.ncep.noaa.gov/Image.php?image=data%2Fgfs%2F18%2Fgfs_namer_240_850_temp_mslp_precip.gif&model=gfs&area=namer&storm=&cycle=18&param=850_temp_mslp_precip&fhr=240&group=Model+Guidance&imageSize=M&preselected_formatted_cycle_date=20141130+18+UTC&ps=model&use_mins=no&scrollx=0&scrolly=85

 

http://www.twisterdata.com/index.php?prog=forecast&model=GFS&grid=3&model_yyyy=2014&model_mm=11&model_dd=30&model_init_hh=18&fhour=240&parameter=DPTF&level=2&unit=M_ABOVE_GROUND&maximize=n&mode=singlemap&sounding=n&output=image&view=large&archive=false

[deltadog03]

Yes, great way to get into the forum!  He is really smart and can learn a lot from his knowledge  lol

[griteater]

Helluva an entry post webber.  The analog maps in your post reiterates why I went slightly cold in my outlook for Dec, but that's going to be a challenge - what I see on the model ensembles right now is one that most resembles a strong El Nino pattern as opposed to a weaker one...and therefore, more of a warm signal for Dec.  Regarding the tendency for Feb to be cold in El Ninos, HM had a good blog post a few years ago analyzing this very subject - http://ionlyusethegfs.blogspot.com/2012/09/why-are-winter-outlooks-for-el-nino-so.html

[Webberweather53]

Not gonna lie, he is a smart dude!!  @webberweather on twitter.  no FB he said Twitter is enough..hahaha

 

PERFECT post, thank you sir!

 

 

Thanks Eric, @webberweather for the bode of confidence.  I love the weather, and this is a great site.  Y'all can follow me on twitter @wxmanchris    and on my new FB page at:    https://www.facebook.com/pages/Wxmanchris/690966551001476?ref=hl    Thanks everyone!  I really do appreciate it.  spread the word, share the pages, and if you want invite your friends.  Not just your typical twitter and FB pages either.  We like to have fun, post pics/videos...etc.  I do try to put them on air as well.  -Chris 

 

Great stats webber and welcome to the board.

 

 

Thanks for your input Webberwx. Very well laid out. Please post more .......

 

 

Nice info webber! That's how you introduce yourself to the forum!

 

 

Thanks Webber! Nice to have another smart person on board.

 

Thanks guys, & I am not going to lie, Chris one of the nicest people I've met through social media thus far & appreciate all of the complements from everyone. As far as this weak correlation between multi year El Nino events & the following winter AO goes, I have tried to isolate a few variables to distinguish confounding factors & what I have noticed is that several months in advance of the winter, even before we begin to monitor the SAI/SCE in October, there's a definitive SST signal within the Kurioshio-Oyashio Extension (KOE) & North Pacific Current east of Japan and east of Newfoundland. Subtracting off the SST in the top 10 + vs -AO winters reveals the largest difference in SSTs in & around 40N (once again), with cooler waters being associated more so with a -AO in the subsequent winter, reason being the cool SST in the mid-latitudes feedback to lower heights & at this "critical" latitude in & around 40N this encourages the jet to extend its nose equatorward & because these cool SSTs were at least partially implemented by wind stress via passing cyclones, we can conclude the cool SSTs in this latitudinal band serve as a proxy for an extensive mid-latitude jet that encourages undercutting & high latitude blocking.

 

September SSTs preceding the top 10 +AO vs -AO El Nino Winters...

Now look at this year in mid september, you can clearly see the tongue of cool water already manifesting itself ~ 40N in both the Atlantic & Pacific a few weeks *before* we started to monitor the SAI

 

 

 

Similar image to the first one, except I flipped the years being subtracted & extended this over the entire globe for the SON tri-monthly period, thus we should see a warm tongue of SST in the KOE/ N Pac Current...

 

 

Now, I expanded this analysis of the AO to all winters & the results weren't quite as convincing...

 

I then excluded neutral events & lo & behold the SST signal actually intensified...

 

Upon seeing this, I suppose that intraseasonal forcing from the MJO may be somewhat at fault here. I've read in several pieces of literature that note the MJO tends to generally propagate more freely in the absence of a significant ENSO event, which leads me to think that w/o low frequency ENSO state predominantly favoring anomalous jet extension (El Nino) or retraction into the Eastern Hemisphere (La Nina), I postulate things can become quite convoluted w/ intraseasonal modulation by the MJO possibly promoting increased variance of the Pacific Jet & hence this relationship to the SSTs begins to fall apart, but this is merely a hypothesis at this point...

[Cold Rain]

Good posts, Webber. We usually try to encourage all new posters to start storm threads for 15+ day events, but I guess we can make an exception in this case. Seriously, welcome aboard! And thanks for dropping some knowledge.

[Webberweather53]

Helluva an entry post webber.  The analog maps in your post reiterates why I went slightly cold in my outlook for Dec, but that's going to be a challenge - what I see on the model ensembles right now is one that most resembles a strong El Nino pattern as opposed to a weaker one...and therefore, more of a warm signal for Dec.  Regarding the tendency for Feb to be cold in El Ninos, HM had a good blog post a few years ago analyzing this very subject - http://ionlyusethegfs.blogspot.com/2012/09/why-are-winter-outlooks-for-el-nino-so.html

Thanks griteater, I really enjoyed your winter outlook BTW... Ironically, I was just about to post that article, lol. He is eons ahead of me in terms of meteorological knowledge and I've already learned a substantial amount of information from him just through periodic interactions on twitter. Hopefully, I will be able to attain that kind of robust knowledge base someday...

[Webberweather53]

Good posts, Webber. We usually try to encourage all new posters to start storm threads for 15+ day events, but I guess we can make an exception in this case. Seriously, welcome aboard! And thanks for dropping some knowledge.

Thanks! I hope I will be able to make significant contributions over the coming winter when a winter storm actually strikes...

[pcbjr]

Assuming it will load and you care - DT's winter update.

 

http://www.wxrisk.com/2014/12/final-winter-update-2014-15/

 

Think I need to move to VA ....

[Cold Rain]

Thanks! I hope I will be able to make significant contributions over the coming winter when a winter storm actually strikes...

No doubt about it! Nice choice with the word "when". I did not take time to conduct enough research to put together a winter forecast, but I am on board for at least a couple of big events for the SE this year, with a few smaller ones sprinkled about. The odds favor being abnormally bullish this year, IMO.

[GaWx]

Thanks! I hope I will be able to make significant contributions over the coming winter when a winter storm actually strikes...

 

Welcome WebberWx!

[Webberweather53]

Welcome WebberWx!

 

No doubt about it! Nice choice with the word "when". I did not take time to conduct enough research to put together a winter forecast, but I am on board for at least a couple of big events for the SE this year, with a few smaller ones sprinkled about. The odds favor being abnormally bullish this year, IMO.

 

Thanks again guys, & I'm glad somebody caught my word selection in that statement...

[GaWx]

Assuming it will load and you care - DT's winter update.

 

http://www.wxrisk.com/2014/12/final-winter-update-2014-15/

 

Think I need to move to VA ....

 

I just looked at it. With all due respect to DT, I think it will verify much colder for the SE for DJF overall than he has. He's predicting a weak El Nino, solid +PDO, solid -AO, and solid -NAO and yet he has DJF averaging near normal temp.'s for nearly all of the SE. Also, I'm guessing he's too dry along the Gulf coast though I'm not as confident about that as I am about temp.'s. El Nino's favor the wettest there and then up the E coast. He's ok along the east coast but he's predicting near to slightly below normal for the Gulf coast. That doesn't fit Nino climo too well.