February 2019 Winter Speculation

[Carvers Gap]

1 hour ago, jaxjagman said:

Believe the GEFS could be right into in it's long range.There looks to be some ridging building into N/S Korea and the Sea of Japan around next Saturday.Some signs the PNA will go negative into the end or start of wk 1 and 2 respectively.But how warm it will get is another thing we'll have to see.The ridge will just be passing thru by the looks right now.

 

 

 

Jax, I just don't know.  I know how the pattern looks on the ensembles...but they did something similar in early January in missing the LR pattern.  When I look at the 18z GFS operational, it doesn't look too bad when just looking at the stormy pattern.  Let's see if that -NAO eventually pops.  Pacific does not look favorable after about d7.  It may be that we get very marginal air, but with favorable storm track(due to the NAO) like the 18z GFS.  And those are the classic El Nino winters that I remember...cold, rainy, some snow, chances at big snows.  Like I said earlier, if we get a big snow during February, nobody remembers a ho-hum pattern at this latitude.   The falling SOI is a good sign.  It actually signaled the pattern change to what we have now.  

[jaxjagman]

2 hours ago, Carvers Gap said:

Jax, I just don't know.  I know how the pattern looks on the ensembles...but they did something similar in early January in missing the LR pattern.  When I look at the 18z GFS operational, it doesn't look too bad when just looking at the stormy pattern.  Let's see if that -NAO eventually pops.  Pacific does not look favorable after about d7.  It may be that we get very marginal air, but with favorable storm track(due to the NAO) like the 18z GFS.  And those are the classic El Nino winters that I remember...cold, rainy, some snow, chances at big snows.  Like I said earlier, if we get a big snow during February, nobody remembers a ho-hum pattern at this latitude.   The falling SOI is a good sign.  It actually signaled the pattern change to what we have now.  

Cold is coming back,it should after this brief spell.The weeklies even show this.

[jaxjagman]

Just saying

[Holston_River_Rambler]

SOI still negative today. According to Ventrice's filtered RMM plots we've stumbled our way into phase 7. Just like last month, about teh time the MJO made it from phase 5 to 6, the SOI dropped into negative values. The VP diagrams look better on week two today (not that they looked too bad before), with the right colors in the right places. 

 

Even worst case scenario with a big ridge in the east, our source region for cold air never loses it, so it should still be getting built up there for when we can get the Pacific to cooperate for a bit.

   

Also looks like EPS is trying for the retrograding Scandinavian ridge -> negative NAO. If the actually works out, maybe it will help stabilize things when the Pacific gets it act together later in Feb. 

 

 

[Carvers Gap]

Not going to sugar coat the 500 pattern beginning at d6 and through the end of the run on the 6z GEFS and 0z EPS.  Trough is in the West and ridge in the East.  The EPS is very warm for our area at 2m in the d10 range.  I am still wary of big model warm-ups as they totally missed the much talked about amplification of the eastern trough during mid-Nov.  Verbatim, that is a tough pattern to break if it evolves like that.  I think it was Snowgoose in the MA thread(yesterday) that said he had his doubts about the EPS verifying as it is out of sync with its own Weeklies...and the Weeklies have done ok this winter if one considers that model goes out to 46 days.  All of that said, just not a good look in terms of temps.  One last thing, February is one of those months where it sometimes snows during a warm pattern.  As I say often, predicting snow is a crapshoot. 

[Holston_River_Rambler]

Just cruising through the NE forum and according to a met up that way apparently there is a lot of spread on the EPS regarding how individual members deal with the PV lobe as it swings through and back to the arctic next week and eventually settles out.  

ORHwxman sums it up:

"The euro is retrograding the PV that swings through back up into the Arctic and over toward AK. That's allowing the huge trough west/ridge east couplet to develop for early February. It may not happen though since there is a ton of spread on the ensembles. But that is why you see some changes in that period. That wasn't forecast even as recently as 24-36 hours ago." 

[Bango]

As john said, its amazing the last couple winters we have been basically punting january's.  Aside from the early December event, weve had 1 or 2 thread worthy events, including tommorrows 1-3 inch potential.   Alot of busted forecasts this year

[John1122]

We are in the worst stretch of back to back to back winters I've ever witnessed. Last year it didn't start snowing until spring. So winter last year was awful. The year before that I had something like 4.5 inches of snow, the lowest I've ever seen here. At 6.5 this year, it's among the worst.  The last time the entire forum area had significant winter storms in January may be 2010.

[BillT]

i speculate that the entire forum ill not see a big snow but more than half of the SE will see snow on the ground and a few locations will be on the high side of the forecasts.....caveat i am not counting florida

[Carvers Gap]

It may be bordering on the edge of  "too late"...but the 18z GEFS has a very strong -NAO late in its run.  IMHO, it likely puts the trough back in the east for the third and fourth weeks of February.  

[tnweathernut]

I am expecting a pretty good pattern and NAO flip by February 10-15, it’s not like we don’t have data pointing that direction.  Data just hasn’t moved to reality........yet. 

What can I say, I like having the football pulled on me as I go to kick it.

[Holston_River_Rambler]

May just be seeing things, but seemed like some hints toward the very end of the 0z EPS that some of the ensemble members see the change now:

 

GEFS sees it too:

 

GEPS less enthused. 

GEFS, EPS, and GEFS mean:

 

[Holston_River_Rambler]

Isotherm offering some thoughts on how we got here:

https://www.33andrain.com/topic/868-global-teleconnections-a-technical-discussion/?page=34&tab=comments#comment-127811 

Key theses for me:

"I believe strongly that the extreme stratospheric event has been a leading factor in "ruining" the winter to date, due in part to by-product domino effects of maintaining a rapid, amplified circulation of MJO signal, persisting rotating and not ceasing / settling in stability of cold phases for more than 1 week at a time." 

"The past 10 days have been back to destructive interference with high coherency in the warm phases. But guess what will save us -- the vortex re-integration at z10; as tropical stratosphere finally warms, and the polar stratosphere cools, the MJO coherency will decrease once it reaches phase 8. This will for the first time since the first half of December [remember: the first half of December was actually a pretty stable cold pattern, because the stratospheric activity didn't increase strongly yet, and MJO was weaker] induce a more stable pattern."

Phrase was bolded by me for LOL effect after last winter.  

Even without him saying it, I'm strat'd out. Can next winter please have no SSW? Two were fun, but I'm ready for something different. 

 

[John1122]

Maybe we need the AO to flip positive. I was looking back at 2015 when we had the back loaded February that produced about 2 weeks of epic winter. During that year when the AO was negative we were warm, when it was positive we were frigid and snowy.  It was 10 and -7 here on February 19th 2015 and the AO was +2.3.

Of course the EPO was -200 to -300 during that stretch an it was running the show. It was also below -100 when we got cold in November and when the December snow storm hit this winter.

It's the best thing we can have when we want winter temps and precip here at the same time. Not sure where it is now or it's forecast. It would be nice if it was able to return though.

[Holston_River_Rambler]

6 hours ago, John1122 said:

Not sure where it is now or it's forecast.

Some of the more reliable strat. people on twitter were saying that there is a delayed reaction and the AO would go positive negative soon, but at this point I'll believe it when I see it.

EDIT: sorry for the confusion. I had originally just assumed the +AO was good since John mentioned it and thought 'oh, yeah, I saw something about that earlier in the week," but it was for a -AO. 

In some positive news, EPS still looks like it is trying to get out of the bad pattern long range, but, as with the above, I'll believe it when I see it. 

 

[Carvers Gap]

So there are days where the timing of weather modeling just makes me laugh.  As expected the Weeklies flip warmish for the next three weeks and don't really look decent until the last week of Feb.   And then......................................................within an hour or so after the Weeklies flipping warm, the 18z GEFS flips in the LR to an eastern trough, like a perfect set-up eastern trough.   To quote someone in the MA(can't remember and to lazy to look), the GEFS looks like the cold Weeklies that have been on so many runs - only now they are not.   I have no idea which will be correct...but I hope the 18z GEFS is correct.  It is entirely possible that the American model suite is handling the MJO poorly, so beware.  

[John1122]

I'd say it's a 60/40 shot that winter is finished, to the extent that it ever started anywhere besides the far eastern areas. My biggest snow was in November before winter started. Wouldn't be surprised to have a warm February and get few wet snows in March. Not sure if it's climate change or what, but I don't think winter and I mean Dec-Jan-Feb has ever been this hostile to snow or frozen precip as it's been the last three years here. Hopefully I'm wrong but I'll have to look out the window and see snow on the ground before I believe it will change this winter.

[weathertree4u]

1 hour ago, John1122 said:

I'd say it's a 60/40 shot that winter is finished, to the extent that it ever started anywhere besides the far eastern areas. My biggest snow was in November before winter started. Wouldn't be surprised to have a warm February and get few wet snows in March. Not sure if it's climate change or what, but I don't think winter and I mean Dec-Jan-Feb has ever been this hostile to snow or frozen precip as it's been the last three years here. Hopefully I'm wrong but I'll have to look out the window and see snow on the ground before I believe it will change this winter.

Hope you are wrong but really share the same thoughts and we missed the snow in November. The last several years have been the same really, big hype in the fall but through one way or another, blame it on whatever indice one wants, the MJO, the Pacific, the AO, the NAO, what have you, they have all ended up the same, with one commonality, seems like it wants to get cold when it is suppose to be getting warm, i.e., Spring!

[Holston_River_Rambler]

EPS now trying for a full CONUS trough

 

2 hours ago, weathertree4u said:

blame it on whatever indice one wants, the MJO,

After this winter, I'm almost to the point where all I care about is tropical convection and SSTs.

ENSO state, nope (that is just a guess at where the convection will hang out and it still moves; it is also just a name for a state and the atmosphere is not a state, but a dynamic system); oscillations, nope (those seem to be impacted by what the convection allows as it shapes the jet patterns); all that seems to matter is where and how strong that tropical forcing is to align the jet.  the jet brings us the cold air and disturbances. If it isn't aligned right, forget it. We have to have cold air, moisture is usually not as big a problem. 90% of our cold air comes from a Pac jet that is split because it comes from upstream in Canada. You have to have tropical forcing in the right places to get that. 

I'm sure something new will happen next winter to change what I think, but right now I really just care about getting that convection into the Western hemisphere and keeping it there through March 15. After that, torch is fine with me. 

[nrgjeff]

Yes the 6-10 day period looks like a blowtorch. Might have a better chance of severe than snow, but odds on both look low.

Week of Feb. 8 should feature a gradual return to cold for the middle of the month. CFS is preferred over ECMWF weeklies. Euro seems to let cold get stuck out West. CFS brings it east, which has support from Nino climo in Feb. Also the MJO is forecast to favor such evolution. Finally the CFS spanked the Euro for early Feb.

I figure the sub-forum area has another shot at snow the middle of February. Once gain might be a risk the Deep South gets more than the Mid South. 

Regarding climate change, the impacts on winter are real. Will leave climo theory to that part of the Board. However, one must take it into account in operational forecasting.

[Blue Ridge]

Thanks for your input as always, Jeff. I certainly am not aiming to travel down the political wormhole that seems to open any time the phrase “climate change” is spoken, but I do believe this to be a major reason why winters/ENSO/etc. seem to no longer behave in a manner to which we are accustomed. 

[Carvers Gap]

Really, really nice look in the LR on the 18z GEFS.  As Jeff noted, that look would give us some chances.

[nrgjeff]

I still think it'll get cold again the middle of February. CFS has slowed down the west to east progression, closer to that of the ECMWF weeklies. Muddled MJO does not look as bullish today; but, this is just a one day fluctuation.

While dense cold air could undercut lingering SER, it will be hard to get snow with 500 mb heights AN. Basically our cold days are post frontal. Any weather system WAA would draw from the warm air just to our south. With particularly dense cold air, ice is a risk that pattern. However ice sucks; so, I'd rather just punt. Weeklies verbatim, the snow chance is pushed later in Feb. It'd be like hitting that clutch 3-pointer late in the game.

Meanwhile the stratospheric PV is buttoned back up tight. Other than the current troposphere blocking, I do not expect additional cold/snow help from the stratospheric PV this year.

[tnweathernut]

On the plus side, we won’t likely have to endure and cold/snow hurt from the PV either.  

[weathertree4u]

14 minutes ago, tnweathernut said:

On the plus side, we won’t likely have to endure and cold/snow hurt from the PV either.  

So, this is it for winter this year 

[tnweathernut]

1 minute ago, weathertree4u said:

So, this is it for winter this year 

 No, I sure don’t think so. In fact if we head where modeling suggests I think the chance for a bigger storm goes way up. Not only that but with a South East Ridge your area may very well do better in the eastern areas.  Of course getting modeling to head where it’s been projected has sure been a difficult proposition so far this year. 

[nrgjeff]

Cold again mid-Feb to late Feb. One more chance at winter. As usual cold will carry more confidence than precip.

Lil' SER could help steer Tenn Valley instead of Deep South. More SER would favor Mid-South over East Valley. Bigger SER would be bearish. (After next week SER should shrink.)

At any rate, I'm pretty sure this is not it. We should have another chance.

[Carvers Gap]

1 hour ago, nrgjeff said:

Cold again mid-Feb to late Feb. One more chance at winter. As usual cold will carry more confidence than precip.

Lil' SER could help steer Tenn Valley instead of Deep South. More SER would favor Mid-South over East Valley. Bigger SER would be bearish. (After next week SER should shrink.)

At any rate, I'm pretty sure this is not it. We should have another chance.

I am not even going to put out a February forecast, because what you stated pretty much sums my thoughts as well(albeit your thoughts are more specific).  If it is to be believed, what a great looking -NAO on the 12z EPS.  If true, confluence would likely be over the Upper South and MA.  Those last two weeks are sometimes a tough score...but we are overdue.  It would be awesome if we could get a storm during this last intermission before the last cold shot.

[weathertree4u]

3 minutes ago, Carvers Gap said:

I am not even going to put out a February forecast, because what you stated pretty much sums my thoughts as well(albeit your thoughts are more specific).  If it is to be believed, what a great looking -NAO on the 12z EPS.  If true, confluence would likely be over the Upper South and MA.  Those last two weeks are sometimes a tough score...but we are overdue.  It would be awesome if we could get a storm during this last intermission before the last cold shot.

Just takes one big storm imo make the season a memorable one.

[Carvers Gap]

42 minutes ago, weathertree4u said:

Just takes one big storm imo make the season a memorable one.

So true.  You know, it is crazy that of many winters that I remember well....they really only had one or two big storms.  I am also big on cold winters.  I like those as well...so this winter is not my type of winter in that regard.  But if we can get a nice storm(already have had one here...so really I can't complain) to end the season, it would be pretty awesome.  I was saying the other day that it would be nice to track a bruiser on the TN subform.  With such an active southern branch, have to think any February cold has a shot - especially the back half.  Talk about a backloaded winter....the last half of February is about as far back as one can get a backloaded winter.  FTR,  I envisioned mid-Jan to the end of Feb...not the last half of the last month of meteorological winter.  LOL.  No idea if the EPS can cold that look, but that is a nice look.