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December/January 2019/20 Winter Speculation Thread

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On 11/25/2019 at 6:05 PM, jaxjagman said:

Looks like the control with no blocking,more crappie west pattern,pattern would be cutter city with cold chasing moisture,we all know how that works out well here

Cutters right now.  Maybe as we get into winter the cold presses.  Looks like a base pattern of a western ridge and eastern trough.  Very little help in the Atlantic.  Looks a lot like the pattern from 14-15 which depended on the northern stream for winter weather.  That 12z EPS ridge today was pretty massive.   Thing is about the Weeklies is it is really tough to tell about amplitude.  They have really missed on that aspect.  The Weeklies have looked pretty bad for most of fall...might be the first time I have seen them workable...they whiffed on November.  Pretty rare to get early December snow here...last year was the earliest big snow we've had since I have been alive.  If we score a storm with an inch or two of snow...would be a bonus.  And honestly, with the SSW on fire right now...really doubt that any model has anything but broad solutions correct. 

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23 minutes ago, Carvers Gap said:

Cutters right now.  Maybe as we get into winter the cold presses.  Looks like a base pattern of a western ridge and eastern trough.  Very little help in the Atlantic.  Looks a lot like the pattern from 14-15 which depended on the northern stream for winter weather.  That 12z EPS ridge today was pretty massive.   Thing is about the Weeklies is it is really tough to tell about amplitude.  They have really missed on that aspect.  The Weeklies have looked pretty bad for most of fall...might be the first time I have seen them workable...they whiffed on November.  Pretty rare to get early December snow here...last year was the earliest big snow we've had since I have been alive.  If we score a storm with an inch or two of snow...would be a bonus.  And honestly, with the SSW on fire right now...really doubt that any model has anything by broad solutions correct. 

Carver, the SSW events are tricky. Sometimes they happen soon and sometimes they take a long time to propagate. It's interesting that Mike Ventrice said a -nam in stratosphere but +nam in trophosphere. 

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Like to know,1977 must have been a great blocking year,i looked back at any SSW and one happened Jan 9th,1977,this was in a weak ElNino year but even the fall temps in 1976 were just stupid cold even this was one of the coldest times even back from into the 1890's, in Tn.,just crazy looking

 

https://sercc.com/climateinfo_files/monthly/Tennessee_temp_DivNew.htm

 

Edit:Sorry,put 1997,meant 1977,i corrected it

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27 minutes ago, Mr. Kevin said:

Carver, the SSW events are tricky. Sometimes they happen soon and sometimes they take a long time to propagate. It's interesting that Mike Ventrice said a -nam in stratosphere but +nam in trophosphere. 

Biggest thing to watch is the 10mb temp anomaly forecast.  Tough to know how if this will reach the troposphere or not...I think it eventually will, but that is only my opinion.   I think when the teleconnection indices get those extreme looks...very likely that the SSW is having some impact at 500mb.  We actually have had some warming this week I think.  It is possible that the models are actually picking up on that event in the LR and that the big warming event beginning in a few days is unlikely to be having an impact on surface weather yet.  IMHO, an SSW is like throwing one of those rubber dime store balls in the living room.  It is going to be spectacular.  It is going to likely break something that cannot be fixed.  And there are gonna be some happy folks, but there are gonna be some mad folks.  About the only think one can predict is that once it is released...it is going to have to take some time to finally run its course as all of that potential energy turns into kinetic energy.  

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23 minutes ago, jaxjagman said:

Like to know,1977 must have been a great blocking year,i looked back at any SSW and one happened Jan 9th,1977,this was in a weak ElNino year but even the fall temps in 1976 were just stupid cold even this was one of the coldest times even back from into the 1890's, in Tn.,just crazy looking

 

https://sercc.com/climateinfo_files/monthly/Tennessee_temp_DivNew.htm

 

Edit:Sorry,put 1997,meant 1977,i corrected it

Sad part of this if you look at the data,this year was the warmest ever in Sept in Tn

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8 minutes ago, jaxjagman said:

Sad part of this if you look at the data,this year was the warmest ever in Sept in Tn

Well,2nd anyways,in 1925 we did average 78.8 in 1925 

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2 hours ago, John1122 said:

The GEFS and GFS are not in agreement at all really. OP is a nationwide torch and the Ens are BN East.

December’s motto for the Tennessee valley, “May the torch be with you”.  I seriously hope we have a decent first month of met winter though.  

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I would guess we will be in a base warm pattern with occasional brief cool shots at least through December 15th-25th. Possibly longer. The 6 week pattern sometimes happens, which would put us in this pattern until January 10th or so.  

Last year we never got out of the ditch all winter. In 2015 after the very cold November of 2014, we got out in January I believe. It was mostly warm through December, 2014 mid 60s Christmas Eve. Mid 60s again January 6th before the bottom fell out for a week or so, then January battled it out flopping around before we had the brutal February into early March with multiple snow and ice storms and well below 0 cold.  

You just get gun shy with these last three winters when everything that could go wrong for winter did. 

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4 hours ago, John1122 said:

I would guess we will be in a base warm pattern with occasional brief cool shots at least through December 15th-25th. Possibly longer. The 6 week pattern sometimes happens, which would put us in this pattern until January 10th or so.  

Last year we never got out of the ditch all winter. In 2015 after the very cold November of 2014, we got out in January I believe. It was mostly warm through December, 2014 mid 60s Christmas Eve. Mid 60s again January 6th before the bottom fell out for a week or so, then January battled it out flopping around before we had the brutal February into early March with multiple snow and ice storms and well below 0 cold.  

You just get gun shy with these last three winters when everything that could go wrong for winter did. 

Yea and honestly, I am not holding out much, if any hope, that this Winter will be any different. So far, I see the same thing, nothing against forum members, but allot of talk about how things are going to change and then it is in reality the same thing, cold/snow in the west, warm and wet in the East. 

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1 hour ago, weathertree4u said:

Yea and honestly, I am not holding out much, if any hope, that this Winter will be any different. So far, I see the same thing, nothing against forum members, but allot of talk about how things are going to change and then it is in reality the same thing, cold/snow in the west, warm and wet in the East. 

Yeah, winters definitely aren’t the same for us in the Tennessee valley like they were 20 years ago.  It’s sucks to say the least. 

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Winter in the 90's were in a really warm period, yet in northeast Tennessee we managed a great snow year (1996) and two other huge snows (1993 and 1998).  I was thinking back to this just a couple of days ago.  As warm and "relatively" snowless as that decade was it provided snows and snowy periods not really seen since.  I just want to have the internet and modeling we have now and to go have something like that to track..........  Can you all imagine how exhausted we'd be if we were tracking another 1993 from 7-10 days out??

As far as where we go in December, I am not at all worried.  Last year parts of east Tennessee saw a major snow before Dec 10th and then winter was largely over.  This year, if it's warm I will just enjoy it and know we have January and February ahead of us.  It can't be as bad as last year. (seems like I have thought this several times in the last 10 years, lol)

Quick everyone, look at the 500 level.  There is a unicorn there, the -NAO.  Maybe it will come visit more as we get deeper into winter. 

Happy early Thanksgiving to everyone on the board!  Hope you enjoy time with family and friends the next several days.  I am sure we can all think of many things to be grateful for....

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I think last winter was a head scratcher because many models and accurate seasonal forecasters(is there such a thing?) had the East as cold.  That is not the case this winter.  Isotherm actually has nationwide warmth.  The Euro seasonal is not BN over the East.  El Nino winters are not known for extreme cold...just their storminess.  There were people last winter who noted in this forum that many seasonal forecasts were too cold.   (My current seasonal ideas are in the summer thread and were posted back in June.  No changes there.)  

Regarding the strat split last winter, it was the real deal and it wrecked havoc.  It did produce extreme cold and snow.  It just went West.  IMHO, the West would not have had a great winter without it.  As Mr. Kevin noted, not all strat splits propagate into the troposphere.  The last two have.  SSWs can have significant and unpredictable impacts on the hemispheric circulation pattern.  Do I think lightning strikes twice and hits the West again with SSW, steroid-type cold?  Nope, but it's not like the northern Rockies are known for warm weather anyway.  What they are getting right now is very much based in Nino climatology which is a cold star to winter.  They did not have a cold and snowy start to winter last year.  It came in February.  I noted the West would likely have a quick start in my seasonal ideas back in June in the summer thread.  However, the NW precip has been below normal this fall I think...until this past week. That is a Nino signature as well.  It is definitely plausible that the EPO ridge could allow for a trough to tuck into the Rockies at times.  

Everyone's burning question is will this winter get cold and we have things to track?  I think so, but I don't get to write the script either.  Given our latitude, we have good winters and bad winters depending on your point of view.  So, the bad winter trend will almost assuredly change.  At some point, it will get cold again.  Jury is still out on this upcoming December.  One could make a good argument either way.  In my thinking regarding December,  I would likely weight AN chances a bit heavier, but not by much. The ensembles last year were cold heading into December and then flipped warm.  The ensembles right now are all over the place.  The SSW that is occurring is earlier compared to last winter which is not uncommon(to the best of my understanding) during low solar and El Nino winters.  Last year, it was in late December with the split in January.  Right now, I can't find any modeling that shows an actual split.  One would think that all of that heat is going to really weaken the PV though.  A weakened PV means that it will likely meander to lower latitudes on one of the major continents or both.  If that PV was wound-up tight...I would be super concerned about a warm winter.  And it is also important to remember, Decembers are truly often warm during El Nino winters..but not all.  Heck, I am not even convinced December will actually be warm, but it likely will be based on climatology.  The 0z EPS( @tnweathernutnoted this above...I was typing this as he posted...ninja!) shows banana type ridging over the top late in its run which, if it verifies, would mean another period of cold sometime during week two or three of December.  Modeling a few days ago was quite warm, and has backed off considerably.  Until this SSW is worked out...tough to really know where this heads.  One nifty analog out there is 14-15 which had a warm December and colder January and February.   The big EPO ridge on the past few runs of the EPS would deliver very cold air into NA.  I do like John's comment that a new six week pattern would deliver a new pattern it January.  I will say, I am not convinced that what we are seeing(ridge in the East) is not a relaxation to the current pattern OR that the December pattern is even worked-out yet due to the SSW chaos.  I think modeling right now is prone to some wild flips due to the SSW situation and the active IOD...lots of plates being juggled right now.

Lastly, as someone who likes to make predictions/forecasts/present ideas...better have a short memory just like a defensive back.  There are going to be times that you get burned and burned badly were everyone is gonna see it.  I called for a warm November last year, and busted.  Just have to go back out there and do what you know to do.  And besides, if we were always right...would it be any fun anyway?  

And have a great Thanksgiving.  Life is short.  Enjoy these temps.  I have almost daily been thankful it is not 95 every day!  I hope I never see that September pattern again.

 

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I do think we maintain the base pattern as a trough in the East and ridge in the West.  That doesn't mean we won't have the opposite at times this winter. That doesn't always mean cold either.  Some troughs are full of Pacific air, and it just rains.  Also, it is pretty rare to have a wall-to-wall trough in the East.  Honestly, I don't worry too much about the pattern in early December.  We just don't get a ton of snow at this time of year...and I say that pretty much every year.   Early December is not a snowy time IMBY regarding climatology.  Best time for snow here  is January though the first two weeks of February..and maybe throw in the last week of December.  So, we really only have a reliable window of six weeks each season which is better than some regions and worse than others.   But let's see where this SSW takes us and where the IOD(which has fired up) takes us.  The IOD may prompt the MJO to take a tour through its warm phases which it has been reluctant to do.  The MJO really does not want to go into phases 4-6 during Nino winters, but one tour won't break us.  The SSW might actually mute the MJO(or even be caused by what is causing the MJO to remain active).  Like I said, plenty of plates to be juggled.  I think a warm-up is very plausible as I noted earlier in the thread.  That said, I think we return to the base trough.  

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57 minutes ago, Carvers Gap said:

I do think we maintain the base pattern as a trough in the East and ridge in the West.  That doesn't mean we won't have the opposite at times this winter. That doesn't always mean cold either.  Some troughs are full of Pacific air, and it just rains.  Also, it is pretty rare to have a wall-to-wall trough in the East.  Honestly, I don't worry too much about the pattern in early December.  We just don't get a ton of snow at this time of year...and I say that pretty much every year.   Early December is not a snowy time IMBY regarding climatology.  Best time for snow here  is January though the first two weeks of February..and maybe throw in the last week of December.  So, we really only have a reliable window of six weeks each season which is better than some regions and worse than others.   But let's see where this SSW takes us and where the IOD(which has fired up) takes us.  The IOD may prompt the MJO to take a tour through its warm phases which it has been reluctant to do.  The MJO really does not want to go into phases 4-6 during Nino winters, but one tour won't break us.  The SSW might actually mute the MJO(or even be caused by what is causing the MJO to remain active).  Like I said, plenty of plates to be juggled.  I think a warm-up is very plausible as I noted earlier in the thread.  That said, I think we return to the base trough.  

Good stuff the last couple of posts, @Carvers Gap.  This may be a bit off topic, but........ It's almost comical when we go back and look through old long range threads we are always talking about the same indexes, what looks good for winter and which things might throw a wrench into things.  All I can definitively say is this science (beyond a couple of days) is one of, it not THE toughest things on earth one can venture into to make educated guesses on.  I feel like modeling has come a long way in the last couple of decades, but I am not sure the professional community/scientists ever (in our lifetimes) make a ton of headway in long range prediction.   The butterfly effect is always working against the smartest individuals the planet has to offer.  It's not like we can expect non-linear equations to ever become linear.  lol

All that said, I can't say how much I appreciate those who do this for a living and how much I am bothered by people with zero understanding cracking meteorologist jokes like it should be easy..

On topic, if a gun was held to my head I'd go with a 65% chance of above normal temps in December with a variable pattern of warm and cold.  A lot of this guess is simply based in climatology and the atmosphere acting like a fairly healthy Nino right now.  The biggest wildcard is the beating the strat is taking and how that may affects things going forward. 

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Speaking of LR difficulties in December and if you want to see a great example of the butterfly effect in full effect, take a look at the 500mb level on tropical tidbits beyond day 10.  This current run (12z) is night and day different over the top.  There is so much blocking showing on this run and it's an almost complete 180 from the last several runs.  Just toggle between prior runs and you will see why educated guesses into the future often fail. 

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Speaking of long range model flip-flops, just as a hypothetical to add to what tnweathernut posted, happy hour GFv3S brings the long range goods. 

giphy.gif

Obviously it is what it is, not meant to be taken literally, all the necessary caveats, but that is a nice possible look with the energy diving towards the gulf and a stuck 50/50. 

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Hi everyone. Happy Thanksgiving. SSW events are tricky. So many parts to consider. They can be game changers. Last year's SSW really didn't materialize. We had a brief pv visit and thats it. It was a major SSW that didnt fully propagate correctly. I think December will be warmer than average imo. I just would like a 6-8 week Avenue of cold and precipitation. 

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Just went back to our historical winter thread,.I more reflect back with what the +IOD is doing in the strong years but i omitted 1997 because we went into a Very Strong El Nino into winter of 1997,but the ENSO in 1994 and 2006 is similar now,tho it could very well be not even into an actual Nino.this year.

1994 we had no SSW and 2006 we had a MAJOR in Jan

Even wiithout the SSW in 1994 i saw where John posted back into 1994 it got colder than hell,not sure where he was talking about but either way -14 is cold everywhere in the Valley,not sure what happened with snow..2006 i believe there was a blizzard in the east in March which effected the eastern parts.

Guess we'll see what happens,you can still get SSWE'S in the low solar min,but it seemingly would be hard to find a good analog right now especially what happening into the IO into early winter.It doesn't help either the PV is knocked off ot it's axis on the wrong side,seems the GFS today after the long haul has sided with the GEFS

 

 

A-sudden-stratospheric-warming-compendium pdf.png

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22 minutes ago, Mr. Kevin said:

Hi everyone. Happy Thanksgiving. SSW events are tricky. So many parts to consider. They can be game changers. Last year's SSW really didn't materialize. We had a brief pv visit and thats it. It was a major SSW that didnt fully propagate correctly. I think December will be warmer than average imo. I just would like a 6-8 week Avenue of cold and precipitation. 

if i recall correct it split more into 3,either way the PV was weak in fall into winter and it finally did the job Dec 31,pretty sure that is right.Happy T-Giving to you as welll

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4 minutes ago, jaxjagman said:

if i recall correct it split more into 3,either way the PV was weak in fall into winter and it finally did the job Dec 31,pretty sure that is right.Happy T-Giving to you as welll

There was just a very brief appearance of the pv into the great lakes and that was that. Whatever we need to have happen to get more excited over a colder stormier pattern moving forward i would like to see. Also, i believe the pv should eventually be back on our side sooner rather than later imo. I know we are in the south and winterstorms are tougher to come by compared to up north. 

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4 hours ago, jaxjagman said:

Just went back to our historical winter thread,.I more reflect back with what the +IOD is doing in the strong years but i omitted 1997 because we went into a Very Strong El Nino into winter of 1997,but the ENSO in 1994 and 2006 is similar now,tho it could very well be not even into an actual Nino.this year.

1994 we had no SSW and 2006 we had a MAJOR in Jan

Even wiithout the SSW in 1994 i saw where John posted back into 1994 it got colder than hell,not sure where he was talking about but either way -14 is cold everywhere in the Valley,not sure what happened with snow..2006 i believe there was a blizzard in the east in March which effected the eastern parts.

Guess we'll see what happens,you can still get SSWE'S in the low solar min,but it seemingly would be hard to find a good analog right now especially what happening into the IO into early winter.It doesn't help either the PV is knocked off ot it's axis on the wrong side,seems the GFS today after the long haul has sided with the GEFS

 

 

A-sudden-stratospheric-warming-compendium pdf.png

January 1994 was a potent Siberian Express situation, with 2 fronts. The 2nd was one of those 20 degree drops in two hours and it was already cold from the first front.  Most areas went ice to snow then got extremely cold behind the 2nd front.  I spent around 9 days below freezing in the heart of January. 

The first front for Nashville was a trace of snow, the temps were 41-39 in advance of the front. It was 39 at midnight January 14th. The temp fell all day and the low was 13 there.  The high the next day was 17 with a low of 5. 36-4 the next day. The second front was coming through the next day. The high was 35 early, the front roared through the state and Nashville had fallen from 35 to 7 by midnight.  It snowed 2.2 inches on top of some freezing rain and sleet there during the frontal passage.  The next day Nashville was 10-0, the following day 17- negative 1. 26-11 and 29-13 the following day.  

It was one of the big 5 winter events for the Valley in the 1990s imo just because of the power and duration of the cold. 

I was going to post about another in the historical thread. The blizzard is legendary for the Eastern half of the region but this event for Valley as a whole beats it in my opinion. It's the massive ice and snow storm of February 1st-3rd 1996. 

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At least in the near term, been pretty nice to see the consistency with the depiction of the NW flow event next Sunday night into Monday AM. 

Moisture all the way up to 500mb with a nice flow off of Lake Michigan:

giphy.gif

 

Gives us this:

giphy.gif

giphy.gif

(Is that a 6" near Blunderstorm?!)

Obviously NE and elevation favored, but I'm curious to see if I can get a flurrific band here SW of the Frozen Head mts with this set up. The flow looks a lot like the one that kept me in flurries all day a couple of weeks ago, if I go by that nice image Knoxtron took of the accumulations from that storm:

giphy.gif

I'm just afraid flow from that direction ain't gonna last too long, so areas that do better with a WNW or NW flow will probably get more bands. 

Happy Thanksgiving!!!!

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Great winters can definitely happen due to SSWs and they can also ruin good patterns IMHO.  Notable SSW events that really enhanced and helped great winters to occur were Jan 1977, Jan 1985, and Jan 2009.  IMHO, last year's SSW did actually propagate correctly to tropospheric levels.  That SSW split into multiple vortices.  Incredible cold and blocking did result as a trough tucked itself over the northern Rockies for months.  Island Park, Idaho, set multiple snow records.  As I had mentioned before, I was in MT/WY/ID during late March and early April of this year.  In West Yellowstone, the snow was stacked up to second floor windows.  They did not have much winter prior to the split of the PV which was a result of the SSW.  February was epic.  Folks couldn't even get to the river's edge on the Madison near 3$ Bridge without skis.  Then, they had to find an entry point to the water.  Some drifts were 10-12' high at the river's edge.  For us, it screwed-up a return to a decent pattern.  Remember how November was cold and that has a reasonable correlation to a cold winter.  Well, the pattern changed on time to a warmer pattern last December after a massive head-fake to cold(multiple head fakes seem to be common during SSW events).  The SSW lasted for much of the second half of December, and the PV split.  The West, which hadn't had much winter at all, then had winter on steroids that lasted well into late June.  

As a note, warming at 10mb, 30mb, and 50mb can occur much earlier than the actual PV split event at the troposphere.  There is great debate (on whether an SSW that does not result in a PV split at the troposphere) can result in major changes in weather at the surface.  I am in the camp that the warming itself is a great indicator of blocking.  What is the great unknown is where the blocking actually develops.   The SSW during later winter and spring of 2018 resulted in a very cold spring with plenty of frozen precip and cold during March and early April.  It took some time for the troposphere to react to that event.  Last winter, the atmosphere reacted well before the event even occurred.  So another variable is lag time.  Those two variables, lag time in affecting the surface and where the blocking sets up, create total havoc in modeling.  We don't have enough analogs to really know how that occurs.  Things like ENSO, solar, and QBO also have to factored into SSW events...and that creates incredibly small analog packages.  

As for the great winters of '77, '85, and '09.  They all had them.  Again, it is important to remember that SSW events usually begin well before the PV splits.  Seems like '09 had warming early in December.  The winter of '85 was a pretty ho-hum winter until mid January.  I don't remember much in NE TN that was overlay notable prior to that split.  The second half of that month and early February would be the some of the worst winter weather(interpret "worst" act cold and snowy) that I have ever experienced.  Spent many sub-zero nights in a crawl space trying to fix broken pipes with my dad.  I remember how tough it was to actually get the frozen water out of the pipe so it wouldn't melt later and ruin the solder joint for the new pipe.  The winter of '85 reminds me very much of what the northern Rockies experienced last winter...very average winter that suddenly flipped to extreme cold and snow.  I don't remember much about '77, just that it was really snowy.  It is of course, the benchmark of what many will say is winter.  

In conclusion, SSWs don't always result in PV splits.  However, IMHO they can still impact high latitude blocking, but not always.  During an SSW look for abnormally strong spikes in teleconnection indices.  Big unknowns about SSWS and ensuing PV splits are where the blocking sets up and how much of a lag(time from SSW to PV split at high altitude to propagating to troposphere) there is.  Those two variables IMHO can create total havoc in modeling.  A small rule of thumb that I use is that when bitterly cold air is dropped into NA, weather models go haywire.  I have also noticed that SSWs can cause models to flip-flop at the last minute as they did last winter.  Many great winters did not have SSW events, but the many of the worst ones have them.  Also, someone check and see if 14-15 had an SSW - that winter is probably the snowiest winter that we have had since 95-96(not an SSW) in Kingsport.  

Great discussion, everyone, and Happy Thanksgiving!

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Also, it should be noted(heard this from JB) that we are actually dealing with two SSWs.  One is going on at present and the other will begin in the d8-15 time frame...that is the one that is really going to heat things up.  Looks to me like the PV gets stretched a bit at 10mb late in the GEFS run.  As HM notes, would be very unwise to "swing for the fences" (with a call for cold or warm) right now with so much uncertainty at high latitudes.   Also note that a brief but near record ridge in the East often precedes a PV split.  Need to be on the lookout for that.  That feature has preceded the last two PV splits.  That much warm air surging into the Arctic is gonna leave a mark.

Also, I think we have had PV splits at the tropospheric levels that were not "top down" events which were results of SSWs.  Double check that...but I am pretty sure sometimes the PV can split without the stratosphere forcing it.  Right now, IMHO, we are still about 15-25 days from really weakening the PV and maybe 10-15 days after that the tropospheric PV gets forced off its spot.  So if we use the six week rule(see John's post above), that would actually fit the timing for a new pattern. Maybe the seeds for the pattern are being planted now.  Also, for future reference, I don't think anyone is calling for major cold over E TN at this point.  Just discussion SSW events.  So, if one of us comes back and reads this thread later....just kicking stuff around, but not calling for an Arctic outbreak.

 

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