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AMZ8990

Long Range Winter Speculation 2018/19

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Euro Weeklies update...I can only wonder "what if" the Weeklies had been derived from the afternoon run which surely would have yielded a cold run.  That said, that was a pretty nice run anyway!  I was expecting warmer.  All but week 3 are cold or seasonably cool w AN precip.  Looks like cold shots rotating down the Plains with some warmth in between.  At this point it would seem a matter of time before one of those cold shots connects with plentiful moisture from the GOM...no idea where, but plenty of cold and energy.  As some have echoed in the MA forum, I am not sure the Euro has the Pacific correct yet.  Most of the teleconnections were neutral, but the pattern still looked blocky.  Not convinced that the Weeklies were cold enough...now you have not heard me say that in a while.  Anyone with access, feel free to add or subtract.

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Just looking at the evolution of the past few runs of the GEFS and EPS, I am growing more confident that the beginning of December will open cold.  I never say it is a sure thing, because one year it looked awesome and went poof!  That runs against my idea of a slightly AN idea for December...but I am fine with that.  Very tough to nail a seasonal forecast with consistency.  But hey, it does open the door for a thaw later during the month...so it might still verify depending on the early departures.  Like I said, my preference would be for the cold to arrive during the second or third week of December.  I like Christmas cold.  Again, if you haven't read isotherm's winter forecast, you need to get your hands on it.  While it does not fit my ideas exactly, I think for us hobby folks...we can learn a lot from something like that.  Again, I am putting most of my LR stuff here so as to give the middle and west TN folks room to discuss the short term this week.  

As a side note....instead of rolling the Winter Speculation thread into the Winter thread.  I suggest in a week or two that someone create an actual December thread.  IMHO, we are just about into actual forecasting mode as the EPS and GEFS will have Dec 1 well on their radar by then.  And this year, I would suggest doing separate threads for each winter month as last year's winter thread became a monster!  For example....December 2018 Winter Discussion.  That is not the gospel, but just a suggestion.  I think it will make things a bit easier to find during later years....

When I see December show up on the LR models in a few days...I know it is "game on" or whatever young folks says these days!  Ha!

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Indeed forecast cold periods verify colder. Forecast warm periods are less so. Blocking themes are often noted. CFS caved to Euro weeklies. November correlates well to December and even somewhat to balance of winter. Nothing special about November, no causation; but, the correlation due to likely common causes is there. Evidence for at least slightly BN temps winter overall continues to accumulate. 

These cutters should settle down a bit later into winter as the jet stream continues its southward march. One has to like an active weather pattern. Kansas had snow twice in the last week. Might not help Tennessee in the short-term, but I like it long-term. Active is good. Oh yeah sleet in Houston TX this morning!

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5 hours ago, Carvers Gap said:

Just looking at the evolution of the past few runs of the GEFS and EPS, I am growing more confident that the beginning of December will open cold.  I never say it is a sure thing, because one year it looked awesome and went poof!  That runs against my idea of a slightly AN idea for December...but I am fine with that.  Very tough to nail a seasonal forecast with consistency.  But hey, it does open the door for a thaw later during the month...so it might still verify depending on the early departures.  Like I said, my preference would be for the cold to arrive during the second or third week of December.  I like Christmas cold.  Again, if you haven't read isotherm's winter forecast, you need to get your hands on it.  While it does not fit my ideas exactly, I think for us hobby folks...we can learn a lot from something like that.  Again, I am putting most of my LR stuff here so as to give the middle and west TN folks room to discuss the short term this week.  

As a side note....instead of rolling the Winter Speculation thread into the Winter thread.  I suggest in a week or two that someone create an actual December thread.  IMHO, we are just about into actual forecasting mode as the EPS and GEFS will have Dec 1 well on their radar by then.  And this year, I would suggest doing separate threads for each winter month as last year's winter thread became a monster!  For example....December 2018 Winter Discussion.  That is not the gospel, but just a suggestion.  I think it will make things a bit easier to find during later years....

When I see December show up on the LR models in a few days...I know it is "game on" or whatever young folks says these days!  Ha!

  I will make a December 2018 Winter Discussion thread right around thanksgiving CG.

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1 hour ago, AMZ8990 said:

  I will make a December 2018 Winter Discussion thread right around thanksgiving CG.

Sounds good.  We are legit pretty close to being able to discuss the December pattern.  That sounds like a good time frame.  Very little speculating left to do! 

Just a short post:  It is interesting to see very reputable mets forecasting exact opposites for December.  I am not totally sure any month is going to be a slam dunk in terms of forecasting - not that there ever is.  The Weeklies have done ok actually.  They had the warm start to November, missed the amplification in the East, but generally had a back-and-forth pattern.  That said, the Euro/EPS have struggled between d10-15 more so than usual.  The CFS2 basically predicted the complete opposite of what is likely to happen for November.  I think Bob Chill in the MA forum basically said the uncomfortable thing right now is that the GFS/GEFS combo is catching changes about three days ahead of the Euro.  Now, I think it has more to do with fall and that sometimes the Euro can struggle with perpetuating a pattern and "miss the turn." There are very few analogs for this year IMHO.  So I do not envy folks who do this for a job.  I think larger scale drivers such as a weak to moderate El Nino are generally good bets.  I think right now, most know that a thaw is coming at some point during winter - always does.  But it has been very hard to predict where it might fall.  I think Jeff had said a few weeks ago that back-and-forth patterns make for tough forecasting.  I think we are likely now in a base cool/cold pattern with brief but very strong warm-ups as interludes.   But I will say this after experiencing the past couple of days...the El Nino pattern surely has to be in the driver's seat now.  Cold rain...not a ton of sun.  Really as I look back on it, this pattern flipped while my family and I were in Montana.  The change was noticeable as well there(got a ton warmer as the week went on).  Pretty wild to fly across country on one weekend and experience the cold that would eventually move into the Plains and be  at TYS the day we got back.  I do think we will see a warm-up around Thanksgiving...but that warm-up has had its wings clipped.  And that is a good sign...we want warm-ups to be shorter and cold to be stronger than modeled.  

Glad that West TN has a chance to track something this early.  

Oddly, as cold as it is forecast to be on the models...Kingsport(NWS/MRX point and click) is not forecast to be below freezing even one time during the entirety of the forecast.  Though to be certain, there is a WSW up to our East and winter wx advisories galore in the west end of the forum area.

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My zonal call looks like it might be measured in hours and not days!!!!  The EPS has stepped into line....  Now, I am always a little distrustful of models that flip.  Why?  Because they can sometimes flip back or "rediscover" the original storm or pattern.   I think November is now highly probably to finish the year BN.  Week. 1 will be above or seasonal in most places.  Weeks 2/3 will likely be below.  I am going to go with seasonal temps for week 4.   TRI is only -0.7 up to this point.  Departures at TRI and Chatt are more signifiant at -2.7 and -3.5, respectively.  Many location in the eastern Valley have only been below freezing once or twice.  TRI's lowest forecasted low for the next week on the Kingsport  point-and-click is 32.  While the lows are BN, the upcoming forecast lows are unremarkable.  It is the high temps that are remarkably low.  And so it goes with El Nino in my experience.  Cloudy days with cold rain is one of its signatures, and this week has lived up to that.  That said, with the final week being seasonal at worst, I think TRI goes BN as well in the -1 to -2 range, maybe a bit lower.  

As for December?  I really like where the models are heading during later November.  But let’s hope my zonal call mojo does not rub-off on this one!   The warm-up on the 0z EPS is basically a ridge that rolls through w a trough sliding in behind it.  I was "hoping" for that, but it is nice to see the Euro cave once in a while.  Like I said(actually Bob Chill said it), the GEFS has been fairly good in catching changes during the past month.  Now, as we head into winter I think it likely the Euro returns to its steady form once the winter season settles in.  Though to be sure, even then, it can have a habit of missing switches.  The Weeklies seem to do ok w that while the EPS seems to struggle making the turn.  So, as long as the models are correct, (and we have seen the EPS likely miss the duration of the warm-up for late November) then the beginning of December looks good.  But I am reminded of those snowy, snow looks last year on the ensembles for late December only to go bone dry...so I will be looking over my shoulder on this one.

Lastly, this relaxation later in the month will be a good test.  Seems like warm periods during the past couple of decades(even if just 3-4 days), have out performed forecasts. In other words, warm has really been very warm.   If this one is muted in reality(regarding after the models have it better defined), I will be encouraged. 

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Griteater posted his outlook also in Weather Forecasting and Discussion. Sorry if it is already mentioned above. Grit is in the Southeast and includes more South discussion.

Well I am now colder than some of the others, which feels strange. However I'm just following my interpretation of the clues. Been a few years since we had 3/5 cold winter months (Nov-Mar) and been several years since they were Dec-Feb. Guess who is forecasting BN temps Dec, Jan, Feb. I revised December colder, making it so in my forecast at least.

I can't really post it here since it is for work. However I can discuss it. So I am -2 Dec -1 Jan and -3 Feb. Yeah I can't believe I'm typing it either. Yes I'm giddy like watching March basketball. Winter precip is all across Dixie early, even if not IMBY. Could if flip? Yes. However with El Nino and the blocking signatures I'll go: Trend is our friend.

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IMME has a weak/moderate basin wide Nino and looks warm in the winter.Must say they all had a rough go at it last month by the looks,though this is preliminary

Lead 1 tmp2m (1).png

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Weeklies looked good with maybe a relaxation later in December(obviously the jury is "still out" on that one).  Oddly, they looked dry from NE TN to Maine.  I think that is unlikely...but I said that last year as well, and we know how that turned out.  It was like a desert for three weeks.  LOL.  Anyway, I think Nino will average out for DJF as AN for precip or normal at least.  For now, I am going to call that a hiccup.

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11 hours ago, jaxjagman said:

Jamstec shows a Strong "Modoki" El Nino in the winter months

ESRL   PSD   Daily Forecasts of Teleconnection Indices  from ESRL PSD Reforecast2 Project.png

That's one of the coldest, if not the coldest, Jamstec depictions I have ever seen.

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25 minutes ago, Cold Rain said:

That's one of the coldest, if not the coldest, Jamstec depictions I have ever seen.

Yes sir, thanks for sharing, Jax.   With all the "pretty" maps floating around and specifically looking at days 10-20, I have started thinking about what can go wrong?  We seem to be marching toward a potential tracking period, albeit really early close on the heels of a system that gave many their first flakes of the year and parts of west TN and KY their first accumulating snow of the year.  This is something we are not accustomed to in the south in late November and/or early December.

When you start seeing the almost perfect placement of features in the 10-15 I start thinking ..................................... We all know models move toward or away from things over time at long leads.  Since they have been looking like a eastern/southeastern US winter "jackpot" the last couple of days,  it's conceivable that modeling will move away from the almost perfect look to something less desirable at verification time.  It will be interesting to see how this potential early start materializes.  In the mid south/southeast one thing is for sure, even with perfect placement of features we still have to have good timing and a little luck on our side.  Before December 20th, probably more than a "little" luck.

These are just a few morning thoughts.  Though I haven't had as much time to post lately as in years past, I very much appreciate all those who have been posting and keeping this forum going.  With the meteorologists we have and the laid back/encouraging posting style of most everyone who hangs out here, I think we have the best forum on AmWx.  Thanks guys/gals, best wishes for a fast start to winter and more snow opportunities this year. (if you like that kind of thing)

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22 minutes ago, tnweathernut said:

Yes sir, thanks for sharing, Jax.   With all the "pretty" maps floating around and specifically looking at days 10-20, I have started thinking about what can go wrong?  We seem to be marching toward a potential tracking period, albeit really early close on the heels of a system that gave many their first flakes of the year and parts of west TN and KY their first accumulating snow of the year.  This is something we are not accustomed to in the south in late November and/or early December.

When you start seeing the almost perfect placement of features in the 10-15 I start thinking ..................................... We all know models move toward or away from things over time at long leads.  Since they have been looking like a eastern/southeastern US winter "jackpot" the last couple of days,  it's conceivable that modeling will move away from the almost perfect look to something less desirable at verification time.  It will be interesting to see how this potential early start materializes.  In the mid south/southeast one thing is for sure, even with perfect placement of features we still have to have good timing and a little luck on our side.  Before December 20th, probably more than a "little" luck.

These are just a few morning thoughts.  Though I haven't had as much time to post lately as in years past, I very much appreciate all those who have been posting and keeping this forum going.  With the meteorologists we have and the laid back/encouraging posting style of most everyone who hangs out here, I think we have the best forum on AmWx.  Thanks guys/gals, best wishes for a fast start to winter and more snow opportunities this year. (if you like that kind of thing)

Good post.  I'm not all that thrilled about the tendency for lower heights in the SW.  I hear year after year about how that's ok because it can lead to overrunning events.  In my area, we need a really good trajectory from the NW via the EPO/upper PNA region and a strong west -NAO to counter the trough in the SW.  That usually doesn't happen (especially the -NAO part).  This year may be different though, so we'll see.  Anyway, the end of the two week period could feature a legit window for the eastern half of TN/western NC and NE from there.  Beyond that, it's hard to find any indication of a hostile winter.  There's a lot to be excited about going into this year -- about as much as you can ask for, actually.

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CFS seems like a joke right now, but in fairness signals are mixed. MJO and the Kelvin waves are a bit muddled. Global wind is up (mild) but so is blocking (cold). At any rate I go with the colder ECMWF due to recent trends. Thanksgiving warm-up is now stronger again on Ops, but overall they keep finding more cold returning late November.

Both weeklies have most of the precip in the Deep South. They show normal over our Region. If you like snow, that is a nice signal. Rain Deep South with the snow band up here. Remember snow holds less moisture; so, I really do not look for AN precip. On the other hand I may be manufacturing dreams from the charts, lol!

More cutters are possible to likely. I believe the secondary storm track will be farther south, which is favorable. With some luck, that farther south track could be primary for a few weeks of the winter. Then we still have to play the familiar game, getting cold air in place. While managing expectations, I'm optimistic. 

Bottom line temps: I prefer the Euro weeklies. They have the Thanksgiving warm-up, followed by variable but average BN temps into mid-Dec. 

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On 11/15/2018 at 8:21 AM, Chattownsnow said:

GFS Ensemble Arctic Oscillation Outlooks

MRF Ensemble Pacific-North America Oscillation outlooks

MRF Ensemble North Atlantic Oscillation outlooks

Ill take this as we head into December! Would like to see the PNA trend more positive but beggars can't be choosers.  

 

Presto.+PNA towards the end of the month into Dec !!Much better right now.There is also a multiple troughs coming out of East Asia  next week.But there seems alot of Volatility with each run.If we could get that look into winter someone will score.But i like yalls area better like Cold Rain said up above.

ESRL   PSD   Daily Forecasts of Teleconnection Indices  from ESRL PSD Reforecast2 Project (1).png

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Found a paper in my links which is easy to read,comparing "EP" (Eastern Pacific) to "CP"(Central Pacific) El Ninos.I seen a couple posters wanting to know more so maybe this is helpful,why we root for a more "Modoki" which the Enso would be more "CP" based.Hope this helps out.But it doesn't mean we wouldn't have a cold winter sorta speaking,we for sure in the Middle Valley root for a Moderate Nino,as  Flash pointed out in his winter prediction post earlier since 1900 when Middle Tn was in a moderate Nino our terciles have never been above the lowest keeping it out of the middle and upper for cold winters(low terciles cold -upper terciles warm).Since more people look here i'll post it here instead of the Enso thread.

 

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011JD016493

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The winter storm from February 16-18 2015 named "Octavia" was the most memorable storm for me. I never took a measurement but I would say over 14 inches of snow fell and was then followed by truly arctic cold. Temperatures I believe fell into the negative teens here and then in the following days a couple more notable winter storms followed after. As a result a snowpack lasted here into the first week of March.  I'm sure almost all of you recall this but I guess because the event was less impactful as a near miss, you don't reflect on it as much. This and the 2011 Super Outbreak earlier in my childhood are what charged my interest in weather. I would kill for a repeat of this with you guys getting more out of it. I know this is unrelated to the discussion. The ENSO conditions were a nada and the sun was more active but the storm snow totals jax showed reminded me of it because it took a similar track and caused a blockbuster event.

Winter Storm Octavia.PNG

20150219_letitgo3.jpg

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In addition to 500 mb blocking I like to look at surface pressure anomalies in the Northern Hemisphere. Started in a buffet line of bashing the SSAI which I still think is a bad tool all by itself. However the SSAI keeps coming back like Cousin Eddie. 

I believe a holistic (whole) look helps. Is Siberian snow due to a zonal active storm track (mild) or associated with cold air in place early and often (cold)? Note I do not claim any causation, but correlation can be useful. Forum has hit the 500 mb blocking pretty well. In addition surface press has been AN in much of the high latitudes. For cold I would also look for more BN surface press in China and the Lower 48 USA. However, the high latitude signal is there. Gin up some storms in China and the USA, and the surface press means may work out.

In other news I have heard 1969 come up as an analog. I have no opinion there, but it was a white Christmas in parts of Tenn.

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7 hours ago, Carvers Gap said:

Don Sutherland, who I respect quite a bit, also released his winter forecast on the main forum.  For those who missed it like I did...here is the link.

 

Don has done some really good work in the past. If I remember correctly, he's not prone to hyping cold and even been more negative than most at times. For this year he's giving double weight to 78, 03, and 2010 in his analogs, so that's being pretty positive about snow and cold. He even throws a bone our way by including Nashville and Atlanta in his snowfall predictions. His total for Nashville was not all that impressive(5-15"), but considering how our 30 year snow drought has tanked the average, not surprising.

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RRWT  looks cold especially into mid Jan,seems like it would fit with the MJO  with an AK ridge setting up for a potential cross polar flow,real cold look

RRWT   Consonant Chaos (1).png

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First two weeks of January show up on the European weekly charts. Looks cold. Here are some thoughts.

1. Blocking signal is strong for weeks 5-6. Normally one expects 50 ensemble members to scatter. This issue the clusters are similar and with lots of blocking. Does not guarantee verification, and short mild interludes are quite possible. However it interests me.

2. AN precip is limited to the Deep South / Gulf Coast. It may be wrong in the moist pattern to-date, but I hope it is right. Snow holds much lower moisture; so, BN precip is OK for snow. Do not want dry NW flow BN. However with rain Deep South, one can infer snow Mid South. 

Speculation only as the thread title shows, lol!

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ECMWF Euro monthlies came out with a cold 500 mb pattern. Monthlies released on Wednesday. Jan. Feb. March all look similar with AN heights over Western Canada and at times Central Canada. The latter scours out some source region with Chinook wind. However they all show BN heights over the Southeast US. Main question is cold air connection. Can the Southeast get really cold? 

Clusters break down mainly into three camps each month. Typically one cluster is classic cold. One is the orange Canada blob; unsettled and cool here, but not particularly cold. Please, just say no to cold rain! Third cluster has AN heights over Bermuda skimming the US East Coast, but not SER hard-core. Cold solutions are out there. I believe some weeks will be classic cold. Then we have the El Nino blah weeks, and of course a few mild weeks. 

With the El Nino CAVEATs and questions, such as cold air in place and mild interludes, I still like a slightly colder than normal winter. Psychology of the mid-December warm-spell can discourage, at least until Day 15 starts looking colder. However the background state and trends have been cold.

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