Winter Speculation 17/18 -December Thread

[Greyhound]

A lot of the Facebook weather Nostradamus prognosticators are already punting the rest of February and saying cold will return in March. A lot of what is discussed here is way over my head, but I'm taking the word of the posters in this forum when it comes to anything weather related. Thanks to everyone for what they bring here!!!

 

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[Carvers Gap]

Some pretty big shifts in the global ensembles last night...I could not see the EPS @ 12z yesterday as WxBell did not update, so it could have happened then.  The 0z GEFS and 0z EPS both show a retrograding Atlantic trough working its way into eastern NA in the Lower 48.  Both begin that transition around d13-14.  For once, they look pretty similar...which is unusual at this range.  Something to watch.  Cold or warm, whatever models show right now is a bit suspect until the SSW after effects stabilize in the northern hemisphere.  We will see if later models hold.  Both models show a very strong -NAO developing. Again, nothing set in stone....

[Carvers Gap]

The 6z GEFS held serve.  Progressive breakdown of the SER after 240.  Retrograding trough out of the Atlantic.  That is a possible scenario given the strong -NAO seen on modeling this AM.  Something to watch.  Not the gospel and may not even qualify as a trend.  Need a couple of more days of this look to be interested.

[weathertree4u]

9 minutes ago, Carvers Gap said:

The 6z GEFS held serve.  Progressive breakdown of the SER after 240.  Retrograding trough out of the Atlantic.  That is a possible scenario given the strong -NAO seen on modeling this AM.  Something to watch.  Not the gospel and may not even qualify as a trend.  Need a couple of more days of this look to be interested.

Things could get real interesting if we throw cold air into the moisture rich pattern we are stuck in.

[uncheelfan]

All i want is a one to two week window with cold air in place and the wet pattern that we are in to produce one good winter system here in northeast Tennessee. Is that to much to ask lol!!!!

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[nrgjeff]

NYC Region sub-forum offers some good debate both directions. Unfortunately ours is starting to sound like Southeast. 

Rest of February is going to be warm. Some of us get paid to make the call unlike academics on Twitter. Note they are excellent at creating ever improving numerical models, but operational forecasting is a different skill set. I'm constantly amazed at what NWP can do now!

March the SSW may start to impact the USA. Unlike other signals (PNA/NAO) SSW often has a delayed impact. ECMWF is still on fire, but some minority clusters bring cold. CFS is totally frozen. It does not take a PhD to go in between. 

I know several of those PhDs. I'm not just name dropping from Twitter. They are excellent scientists and amazing people. 

[Carvers Gap]

This is not even remotely close what goes on in the SE forum.  Sorry, can't disagree more.  I am not even going to give the rest of that the time of day.

[Carvers Gap]

Another interesting Tweet from Allan Huffman.  If I am not mistaken, he does a lot of work for this site.  His comments support the idea of a return of high latitude blocking during late February and the idea that the SSW will indeed have an impact on NA weather, not just Asia.  The SSW does correlate with high latitude blocking.  Again, this is not the gospel.  It is not about being right or wrong.  This is a thread about speculation, learning, and figuring out the pattern.  We will never learn unless we take risks.

 

[Carvers Gap]

Anthony is HM on this site and has been a big contributor on the general discussion forum and in various subforms.  Here is another great Twitter thread from him.  It is a good read.  

 

 

[Vol4Life]

35 minutes ago, nrgjeff said:

NYC Region sub-forum offers some good debate both directions. Unfortunately ours is starting to sound like Southeast. 

Rest of February is going to be warm. Some of us get paid to make the call unlike academics on Twitter. Note they are excellent at creating ever improving numerical models, but operational forecasting is a different skill set. I'm constantly amazed at what NWP can do now!

March the SSW may start to impact the USA. Unlike other signals (PNA/NAO) SSW often has a delayed impact. ECMWF is still on fire, but some minority clusters bring cold. CFS is totally frozen. It does not take a PhD to go in between. 

I know several of those PhDs. I'm not just name dropping from Twitter. They are excellent scientists and amazing people. 

As Carvers stated, forums were created as an avenue for discussion and learning.  Obviously, in order to have a forum, you must have members.  There have been numerous mentions this winter of wanting to grow this forum.  Unfortunately, pompous posts like the one above will not only hinder growth, but also the objective of this forum.  I sincerely hope this is an aberration.

[Carvers Gap]

Back to the weather.  Winter is over whenever it is over.  It may be over now, and it may not be.  I think we all concede that at this latitude.  @John1122 was the first to mention that this winter had a similar feel to '89.  He has been pretty steady with that idea and though it might not match the exact dates of 1989, the flip to sustained warm looks like a decent idea.  I generally ride winter to the last of the mountain snows which I think occurred during May last year.  I continue to think that the models are not handling the post-SSW pattern well.  The changes in the ensembles were interesting overnight, but certainly not a trend yet.  They could be hiccups or even blips in an otherwise SER dominated pattern OR they could be finally catching on to the SSW impacts.  I certainly hope that blocking develops because it would help support many of the ideas put forth on this forum, but just no way to know at this point.  Either way, it has been very interesting watching the strat warm.  Many in this thread have discussed the correlation between high latitude blocking and the potential impacts that an SSW could have in NA.  I do not necessarily agree that the SSW has a lag.  I think the effects in the troposphere will be felt quickly within a day or two of the potentially complete split of the PV.  However, there is likely a lag in building potential blocking over Greenland.  Obviously, the reorganization of hemispheric flow will not develop overnight.  I think my thoughts have consistently been a cold shot returning between February 20th and March 10th.  I said then that I was on shaky ground, but just was not going to flip back and forth, especially given that many signals pointing to a return to BN temps.  I still feel that is a decent call, but who knows?  Like I said, I have zero problem being wrong.  I do this as a hobby and enjoy it.  One does not jump into weather as hobby because they expect to be correct.  Not sure one single model showed high latitude blocking due to the SSW when the correlation between the SSW and high latitude blocking was discussed in this thread.  I am pretty sure that the Weeklies flipped warm many runs ago, and we continue to discuss the idea that they may be wrong.  The current Weeklies do have some high latitude blocking but are warm.  No way to say folks in this forum are model hugging....not one model on the planet showed blocking (maybe discussion began two weeks ago...maybe a little less) when the SSW and -NAO were discussed.  Discussion of the potential for the synoptic pattern changes occurred before the models showed any hints of blocking over the Davis Straits....and it is still not a given that the -NAO develops, or if it does develop, that it brings cold to this forum region.  Here are the CPC ensembles from today.  I can tell you the the NAO was not negative on that model last week.  The AO is severely negative.  Again, this could easily not verify as the models are still sorting out the post-SSW effects.  But I do think that it is growing likely that the SSW is going to impact North American wx and not just Asia in terms of cold.  The MJO on the ECMWF is now taking the tour through the cold phases of 8,1.  After stalling in phase 7, the GEFS MJO now moves into phase 8...barely.  That MJO progression does correlate with what is seen on the modeling.  

[John1122]

We will see if the Atlantic can get anything done. I feel with the -PNA and the EPO going positive that we might have to work with Pacific air instead of Arctic air. I won't rule out by any means that we can see more snow. I just think any sustained Arctic cold is off the table.  I've seen Atlantic blocking spoiled by the Pacific before in that regard. Late February into Mid March can be volatile for the entire forum regarding snow/cold. There are many examples of almost snowless winters seeing large snow dumps in that window. Nashville's largest snow ever came during a winter when .5 inches had fallen before March. Then they got 4 inches after a period of 70 degree weather on March 13th and 17 inches on March 17th.

The rest of the season we're probably going to have to hope for something like that. A perfectly timed system that meets up with perfectly timed cold. A few years ago we just had cold city from February 20th til March 10th or so and we just sat and watched systems attack it. I don't see that happening this year but I truly hope I'm wrong. In the interim we will have to see if we can space the rain out enough to avoid major flooding. The ground is like a soaked sponge here and there's been a decided lack of sun even when it's not been raining. It's hardly shone for a week it seems like. 

[Carvers Gap]

Good post, John.  Yeah, relying on the Atlantic right now(when it has been absent from the equation for the past couple of winters) is sketchy at best.  But it does look like that might happen.  Now, what is the air mass source if that happens?  That is the question and a good question at that.  The Pacific is definitely an option for source air masses w the EPO and PNA looking the way they do.  I am really wanting to see these systems slow down when they hit the block.  I am not sure which is tougher to score with....cold -EPO flow from the Arctic or Pacific air hitting a -NAO block as part of a coastal storm.  I wonder if it might just be cold enough.  If the -NAO verifies, I suspect that we will see some coastal storms.  I also suspect that the -NAO (as HM stated yesterday) that the block will retrograde into favorable position so as to deliver cold, but that is TBD.  I can certainly see a path to mild as the models have depicted that for several days.  I can also see a path to a full continental trough which might be another solution that the teleconnections are hinting at.  One thing is for sure, it will be interesting to see how this evolves.   

Yeah, it is crazy how wet this pattern is right now after weeks and weeks of dry ground.  Like a different world up here.  

[Stovepipe]

Carvers, just wanted to say that the bits you post from other sources are very much appreciated as is your excellent insight.  You've really stepped up your game this season and we are all better informed as a result.  Good job!

[John1122]

I echo Stove, there are quite a few people who bring a specialty knowledge to the forum. I appreciate you all. This hasn't been the most engaging winter for the Eastern half of the region but it was pretty good for the Western areas and filled with a lot of potential since it was at least cold. This reflected in forum growth and forum views. I know many go into hibernation after winter. But I hope you keep coming back next fall/winter even if you don't stick around in the summer. Also, if you're reading this and don't post, give posting a try. I always like hearing from new people and new areas. Especially since our entire forum covers very diverse climate areas over a fairly small area. I find microclimates fascinating. 

[nrgjeff]

1. Newbies don't take my rant as unwelcoming. Definitely agree every original post adds to the forum. We have people with more local micro-climate knowledge than any Met degree can replace. Keep posting!

2. The road to cold in March is -NAO; otherwise, it's over like the KU basketball season.

3. Before writing my admittedly brash post, I thought about it Friday and forgot all about it. Actually I was not going to write it, until I saw the weekend posts. We all see the same stuff on Twitter. This forum should be original thoughts.

4. This really will be my last winter post, no matter how much I might be baited. I will post in severe, mainly for those who are afraid of it. Most of the time the hype is wrong.

[Icy Hot]

nrgjeff- last post even if we score a blizzard of 2018 in March???

[Carvers Gap]

That weekend crowd is a rough bunch.  

Thank you for the kind words Stovepipe and John.  I agree.  Keep posting folks.  Everybody is welcome.  Would be a boring place without all of you.  Now, on to the weather....

The 12z EPS has the weakened SER late in its run.  Nothing new really to add to the commentary from this morning....looks a lot like this AM’s run with maybe slightly less retrograding, but that is likely just variances within the model and is to be expected.  The 12z GEFS is in quite good agreement at LR w the EPS.  It is probably not fair to ask both models to be in agreement in the d10-15 range, but they are.  Is it a legit trend yet?  Ask me when it is within ten days.  I am suspicious of any model trends right now.  What I know is that there should be blocking at higher latitudes due to the SSW.  What we cannot know for sure is the configuration of that blocking and how it interfaces with our weather here yet.  I suspect we see intrusions of cold and storminess on the EC.  Looks to me like the last week of Feb is the potential beginning of that pattern...if it actually verifies.   Until then, base warm pattern with brief intrusions of cold.  Plenty of rain on tap.  

[PisgahNCWeather]

Just now, nrgjeff said:

1. Newbies don't take my rant as unwelcoming. Definitely agree every original post adds to the forum. We have people with more local micro-climate knowledge than any Met degree can replace. Keep posting!

2. The road to cold in March is -NAO; otherwise, it's over like the KU basketball season.

3. Before writing my admittedly brash post, I thought about it Friday and forgot all about it. Actually I was not going to write it, until I saw the weekend posts. We all see the same stuff on Twitter. This forum should be original thoughts.

4. This really will be my last winter post, no matter how much I might be baited. I will post in severe, mainly for those who are afraid of it. Most of the time the hype is wrong.

Say it ain't so Jeff.  

 

[ShawnEastTN]

Like John was mentioning earlier there are a lot of us that are only here for the winter, I am one of those folks generally speaking though I poke at the forum late summer and fall for long range banter but don't contribute.  Long range climatology is generally way over my head that I don't partake trying to piece all of it together other than to read what everyone else contributes and their summaries.  I do enjoy reading those even if some are far fetched.  Though I also enjoy Jeff's frankness/sarcasm, I don't regard it as being negative in anyway at least not being negative to be negative.  We always have winters that look great then fail to deliver sometimes forum wide, other times for parts of the forum.  The uncertainty is what makes it interesting for me and most addictive, if big snows were certain every year I likely would never be on the forum.  For me its the thrill of the chase I guess (probably a bigger theme in my life in general) that keeps me interested.  Without the years that suck we wouldn't have those seriously memorable years for me 93, 96, 2010, and 2015 to name a few.  Though I have to say this year will be memorable for the long duration cold.  

Seriously I really love our forum, and everyone who contributes and look forward every year to the chase to begin all over again.  I joined the forum the winter of 2013/14 after getting completely fed up with crappuweather forums for years before that, have never looked back.

[Bango]

1 hour ago, ShawnEastTN said:

Like John was mentioning earlier there are a lot of us that are only here for the winter, I am one of those folks generally speaking though I poke at the forum late summer and fall for long range banter but don't contribute.  Long range climatology is generally way over my head that I don't partake trying to piece all of it together other than to read what everyone else contributes and their summaries.  I do enjoy reading those even if some are far fetched.  Though I also enjoy Jeff's frankness/sarcasm, I don't regard it as being negative in anyway at least not being negative to be negative.  We always have winters that look great then fail to deliver sometimes forum wide, other times for parts of the forum.  The uncertainty is what makes it interesting for me and most addictive, if big snows were certain every year I likely would never be on the forum.  For me its the thrill of the chase I guess (probably a bigger theme in my life in general) that keeps me interested.  Without the years that suck we wouldn't have those seriously memorable years for me 93, 96, 2010, and 2015 to name a few.  Though I have to say this year will be memorable for the long duration cold.  

Seriously I really love our forum, and everyone who contributes and look forward every year to the chase to begin all over again.  I joined the forum the winter of 2013/14 after getting completely fed up with crappuweather forums for years before that, have never looked back.

My thoughts as well, i ve learned to recognize that when we start discussing intense mjo or ssw events, it aint good for winter lovers ha.  But i do enjoy skimming through them.  Good forum

[Carvers Gap]

4 hours ago, nrgjeff said:

1. Newbies don't take my rant as unwelcoming. Definitely agree every original post adds to the forum. We have people with more local micro-climate knowledge than any Met degree can replace. Keep posting!

2. The road to cold in March is -NAO; otherwise, it's over like the KU basketball season.

3. Before writing my admittedly brash post, I thought about it Friday and forgot all about it. Actually I was not going to write it, until I saw the weekend posts. We all see the same stuff on Twitter. This forum should be original thoughts.

4. This really will be my last winter post, no matter how much I might be baited. I will post in severe, mainly for those who are afraid of it. Most of the time the hype is wrong.

Edited.  Response is in banter.

 

[Carvers Gap]

Back to the weather...

The 18z GEFS continues w depiction which began overnight of a strong Greenland block and a retrograding trough into the EC late in its run.  But as one of our best posters will say, "But is it right?"  Time will tell.  No way I am hanging my hat on a global past d10 w the current volatility in place.  But better than just looking at a mega SER.  If models show that tomorrow, I am willing to give it some consideration as a trend.

[Carvers Gap]

Interesting to see the variations in -NAO responses to the SSW.  The Euro (which I do not trust past d10) is weaker w the -NAO while its ensemble is stronger.  I suspect the operational not going past d10 has some influence there.  But that is a possible solution.  The 6z GEFS builds a pattern w high latitude blocking that would force storms under the block and is a decent looking set-up if one considers that is so far out there.  Here is a Tweet of the differences seen between the 0z Euro and 0z GEFS...I think the GFS and its ensemble probably overdo the NAO past d10 while the Euro's response to the NAO creates a striated northern hemispheric pattern that does not look realistic at 500.  So the question remains...how does the -NAO impact eastern NA weather.  I think the jury is still out, but I still think the SER is gradually eroded and replaced with a trough sometime during late February or even early March.  

 

 

[Holston_River_Rambler]

One thing that I've noticed this year and maybe only because I've heard it mentioned by others (don't think it was in our sub forum, but could be wrong) is that models have really large scale things programmed into them at initialization, things like ENSO state, MJO state, things that are, as I understand it, supposed to help during stable patterns, but may not be as helpful when the flow is fast or transitioning. To be honest, I'm not sure if any of that is accurate but since were looking for a change, I thought I'd throw it out there. Not because I'm rooting for one out come or another, but to try to understand how things work better, so someone correct me if this is not right. There is often discussion of "the trend is your friend" and that global models are "slow to adjust" regardless of the outcome (although that last phrase in quotes sometimes seems to be thrown out when the NAM or RGEM is showing some epic snow and the globals aren't, so there could be some wishcasting it that one).  The MJO is still in 7 and the Nina is being attacked (from I've read from others) by a downwelling Kelvin wave.  The Strat is a done deal, but watching how models are handling the results at 500 mb seems to indicate the +NAO of doom won't go down without a hard fight, but it will go down (where things go after there is up in the air). All this makes me think it will still be a bit for clarity, but what else is there to do right now other than check out waterfalls, buy paddles, and watch rain gauges fill up. 

Looking at all this I'll go ahead and make an original call, following Rambler's Random Rules #1 for snow in the Great Eastern TN Valley: "If a specific snowstorm for a specific place is forecast at long range, it ain't happening". Corollary to rule #1: "best TN Valley snowstorms happen when the general public seems to be unaware up through 48 hours before" (this is why I'm superstitious about talking snow with family and friends) Simply put this rule says that sensible weather at a specific location is hard to predict at range. (well duh!) This rule is formed from observations of weather in TN valley my whole life. Almost every snowstorm that I've heard people ask about 3+ days out has ended in failure.

Call: In light of this and rule 2 (coming up), I think the best window for whatever will materialize will not be at the beginning of whatever pattern sets up in March, but at the end. Maybe second week of March or later. This may rule out most valley locations, but March is what March is. I just hope some sort of epic storm, whether it be here or NE or OHV or the plains ends this Nina and helps ring in Spring. But I speculate that when people (and here I feel like TN Valley folk  are fairly leveled headed, so some of this may be in other forums) start to see a great pattern and get a couple of threats to track, there will be a tendency to be disappointed since things have been like they have been this winter. Disappointing! Yet, I shall keep hope:

Rule #2: (learned from reading these forums) "Storms often end patterns, not start them." 

[Carvers Gap]

Pretty big changes afoot on the MJO.  For the past several days the GEFS has beens stalled in phase 7.  The ECMWF has regained its footing and the GEFS appears to have corrected overnight.  It goes decisively into phase 8 now.  Now, to the credit of the GEFS is did nail the high amplitude phase 6 and 7 which I did not think it would.  Its current forecast is now low amplitude into phase 1 and then COD.  I have a feeling that is not done correcting.  And I do agree to some extent that when we have talked about the MJO, things are warm here.  However, it has correlated very well this winter to the pattern so it is worth a look.  It signaled the December cold.  I think phase 8 will signal the return to cold now.  Also, this SSW is a pretty awesome event.  It is interesting, no matter the outcome, to see the PV split on modeling.  

[nrgjeff]

The Philippines had a somewhat out-of-season tropical storm. This is separate from the southern Indian Ocean cyclone. Carvers is probably right that MJO forecasts are tricky right now.

I still think the SSW will have impacts in March. Hopefully while ski areas have discount lift tickets. -NAO might be the road to cold, but it's too early to tell. Alaska could surprise. 

I am the only person on this board that owes anyone an apology and it is in Banter.

[Holston_River_Rambler]

2 hours ago, Carvers Gap said:

Pretty big changes afoot on the MJO.  For the past several days the GEFS has beens stalled in phase 7.  The ECMWF has regained its footing and the GEFS appears to have corrected overnight.  It goes decisively into phase 8 now.  Now, to the credit of the GEFS is did nail the high amplitude phase 6 and 7 which I did not think it would.  Its current forecast is now low amplitude into phase 1 and then COD.  I have a feeling that is not done correcting.  And I do agree to some extent that when we have talked about the MJO, things are warm here.  However, it has correlated very well this winter to the pattern so it is worth a look.  It signaled the December cold.  I think phase 8 will signal the return to cold now.  Also, this SSW is a pretty awesome event.  It is interesting, no matter the outcome, to see the PV split on modeling.  

I'm guessing you saw this Carvers, but maybe not... The Euro MJO forecast looks even more auspicious in regards to what you posted above: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmf.shtml 

I also think I remember reading on another board that the GEFS does better when initializing in some phases than in others. Maybe some phases support more progressiveness and that might fit a bias it has?? 

Dug around and I found and downloaded the article that was mentioned for this, but alas it was too big to attach by 1.1 MB. Here is the citation: 

Kim, D., Kug, J., & Sobel, A. (2014). Propagating versus Nonpropagating Madden–Julian Oscillation Events. Journal of Climate, 27(1), 111-125.

Not sure I could give anything approaching a proper summary of explanation of the research now, but maybe others can or at least we can use it as a possible refernce for the future

[jaxjagman]

On 2/12/2018 at 7:45 PM, Holston_River_Rambler said:

Indeed. Hope was kindled. Crankyweatherguy (http://www.stormhamster.com/entry/e021218.htm ; mostly forecasting for the 95 corridor) also helped light the beacons by showing the Bering Straight Rule for 3/1 - 3/5. Not too confident in how I read these BSR maps, but superficially it looks good. 

The BSR the way it works,you probably know this already but others might not.It's a 17-21 day time frame -2/+2,so the map is splitting the difference as it's showing day 19.So this map in general wouldn't  be 1-5 of March it would be Feb 28-March 4,maybe nitpicking but that's how it works.But as far as that map goes i really don't know if it's going to be right.The Euro and GEFS for that matter both show a system going through Shandong,China into the Yellow Sea.Also, this map was also made around the SSWE.Map shows a H into the Atlantic,long range models shows a L.Maybe it's right,but i'd use it with caution right now.

[Holston_River_Rambler]

Thanks for the reply Jax. Like I said, I am no expert in the BSR and definitely happy to learn more in how to use these! I understand the jist of it, but this explanation makes it a little clearer. Thanks for the info!

So maybe safer for just vague periods of storminess or relaxations, but maybe not so much for specifics?