December/January 2019/20 Winter Speculation Thread

[Holston_River_Rambler]

One thing I noticed on that OP run was that the Hudson Bay ridge really, really wanted to retrograde to Alaska, but the PV piece there kept it locked in. 

Maybe this AAM spike is trying to force that HL blocking for a typical Nino look and the PV piece is just locking it in there? 

I sped it (only hours 72 -204) up so it seems more apparent:

[Holston_River_Rambler]

Member 16 of the GEFS had a little 93, with snow from Louisiana north and east. 

[Wurbus]

Just a slight flip on the GFS from the previous run at 300.

18z

00z

[John1122]

Yep, completely different look at 500 means different everything. Pretty standard GFS flop. 

[John1122]

The GEFS snow mean actually got a little better for the Valley region vs 18z. It's not really from some massive big hitter on the individual members either. There's a pretty steady agreement across a lot of members for snow, especially along and north of 40 where the mean on there is 2+ inches.

 

 

[Holston_River_Rambler]

5 hours ago, Wurbus said:

Just a slight flip on the GFS from the previous run at 300.

OP Euro was pretty bad at 240 too.:

A zonal look in mid to northern Canada. Without that big upper low in the plains, you'd have a subtropical ridge across the whole CONUS, lol. 

The Control evolves that look to some ridging over AK. 

EPS looks like it is split between some members keeping the TPV over AK and some members seeing the ridging. 

Actually some convection around the dateline, but north, this AM:

The Indian ocean looks about the same, but there is a critter of some kind creeping west from around Sri Lanka:

Meanwhile the SPV looks stout and only getting stouter:

But all the cold air is on our side of the globe at the end of the EPS:

No sloshing needed!

And it'll all look different in 12 hours, lol. 

 

[weathertree4u]

5 minutes ago, Holston_River_Rambler said:

OP Euro was pretty bad at 240 too.:

A zonal look in mid to northern Canada. Without that big upper low in the plains, you'd have a subtropical ridge across the whole CONUS, lol. 

The Control evolves that look to some ridging over AK. 

EPS looks like it is split between some members keeping the TPV over AK and some members seeing the ridging. 

Actually some convection around the dateline, but north, this AM:

The Indian ocean looks about the same, but there is a critter of some kind creeping west from around Sri Lanka:

Meanwhile the SPV looks stout and only getting stouter:

But all the cold air is on our side of the globe at the end of the EPS:

No sloshing needed!

And it'll all look different in 12 hours, lol. 

 

Exactly! It will likely all look different with the noon runs!

[Carvers Gap]

Nothing really to add at this point.  Great discussion overnight.  The Renaissance of the Renaissance continues.  About the only think I can think of at 6:45AM is that if that PV were to dislodge with the mean trough now showing up over the eastern U.S......got about a 50/50 shot at extreme stuff. But at this point, I am not sure we want it disrupted with our fair share of cold already here.  We will see where the MJO is this morning.  The 6z GFS again has a parade of winter storms and potential winter storms.  

[BhamParker]

Models are really backing off on the weekend snow threat it seems. I guess we have time to turn it around, but it was looking like a nice event for the higher elevations at 00z yesterday and ever since then it’s just kinda crapped out. Still some ensemble support from the EPS, but most are very very light. Do these type of events for higher elevations, sometimes not show up as well on the model output or get better close to time?

 

I noticed with this last system yesterday and overnight, the models were not spitting out any snowfall accumulations to really speak of and places still reached up 1-3 inches in spots. 

[Carvers Gap]

Bham, looks like models have converged on sending stronger energy to our west with the secondary forming nearly at our same latitude.  We need that secondary to be stronger and forming earlier to our SE.  Still a couple of runs for that to potentially change back.  This is a notoriously tricky set-up.  Usually energy transfer situations where the slp reforms over the Piedmont favor far NE TN and SW VA.  Right now, even those areas have seen the storm back off.   Might see some upslope once it passes though.  Just gave one final glance of the Euro...looks like the highest elevations will deal with mixing and snow during the first part of the event.  Then rain.  Then some upslope snow at the end of the event.  

[Holston_River_Rambler]

Maybe this will add some excitement to an otherwise blahhh model day:

Does this mean we get a new CMC at 12z today? 

[AMZ8990]

3 minutes ago, Holston_River_Rambler said:

Maybe this will add some excitement to an otherwise blahhh model day:

Does this mean we get a new CMC at 12z today? 

 

  Sounds like it to me!!

[BhamParker]

49 minutes ago, Carvers Gap said:

Bham, looks like models have converged on sending stronger energy to our west with the secondary forming nearly at our same latitude.  We need that secondary to be stronger and forming earlier to our SE.  Still a couple of runs for that to potentially change back.  This is a notoriously tricky set-up.  Usually energy transfer situations where the slp reforms over the Piedmont favor far NE TN and SW VA.  Right now, even those areas have seen the storm back off.   Might see some upslope once it passes though.  Just gave one final glance of the Euro...looks like the highest elevations will deal with mixing and snow during the first part of the event.  Then rain.  Then some upslope snow at the end of the event.  

I’ll be pulling hard for some positive trends over the next few days. I’d just love to see a 1-2 inch event up in the smokies, but will has a great time regardless. It was crazy how good the 00z Euro, GFS, and Canadian were just yesterday and then the change was so drastic. 
 

Thanks for the response! 

[Holston_River_Rambler]

UKMET still looks upslopey and even had a little bit of Gulf moisture snow at the very end:

Magical new CMC look like it might have been heading somewhere after 240 hours, but otherwise, same old pattern. 

[BhamParker]

Looks like the GEFS at least had more members with snow on the 12z run, but they are all light. That UKMET looks nice. 

[Carvers Gap]

I think this is cold chasing rain so far regarding this this weekend.  Looks like the Euro is on board with that too.  Wish I had better news.  Cold rain and then some upslope snow showers on Sunday.  

After that, looks like patience will be a virtue as the next encompassing cold shot is due sometime around Feb 5.  Might still get a chance for snow before that.  However, if LR guidance is correct...the wait is on which was expected regarding the Weeklies run overnight.  

[PowellVolz]

I think this is cold chasing rain so far regarding this this weekend.  Looks like the Euro is on board with that too.  Wish I had better news.  Cold rain and then some upslope snow showers on Sunday.  
After that, looks like patience will be a virtue as the next encompassing cold shot is due sometime around Feb 5.  Might still get a chance for snow before that.  However, if LR guidance is correct...the wait is on which was expected regarding the Weeklies run overnight.  

I think this is pretty much where we are at until we can get a climate shift. Outside a few years we have been running in sand for 20+ years.


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[Carvers Gap]

1 hour ago, PowellVolz said:

 

I think this is pretty much where we are at until we can get a climate shift. Outside a few years we have been running in sand for 20+ years.


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In NE TN, we have had some really good winters during the last 15 years and some not so good ones for sure.  13-14 and 14-15 were really good.  09-10 were really good.  14-15 is the most snow I have ever seen in Kingsport during a winter.  In January of 2013, we had thunder snow here.  December of 2018 was super cold.  Last winter we had a foot in early December.  It has not been easy for you all south of of I-40 for sure.  But up here, I can't complain.  Unfortunately, non-winters are a norm in Kingsport from time to time, and they usually come in bunches.  The 90s were considerably worse.  I thank my lucky stars every day not to have to live through those non-winters again(some notable great winters were during the 90s...but many were awful).  On this side of the valley we need the AMO to flip in order to get more help from the Atlantic.  We need that extra kick from a -NAO as part of our precip pattern is form Miller A stuff as you know.  Knoxville's winters became considerably worse from about 1988 onward which is around when the AMO flipped.  In Knoxville, I would say the winter bad winter cycle, excluding some good years, is running at about three decades.  Probably have 5-10 years before it flips again.  Maybe we will get lucky and it will flip sooner.  The AMO trajectory is definitely declining. 

As for this weekend, it was always an outside shot.  We will see where February goes.  

[Coach B]

5 minutes ago, Carvers Gap said:

In NE TN, we have had some really good winters during the last 15 years and some not so good ones for sure.  13-14 and 14-15 were really good.  09-10 were really good.  14-15 is the most snow I have ever seen in Kingsport during a winter.  ........ We will see where February goes.  

I wish you hadn't mentioned 13-14 and 14-15. I've tried to banish them from my memory. That was a great time to bust out of the long term snow drought, but SW and most of middle TN managed to screw up even in those cold years with some great patterns. 

Agreed on the wait and see for February. The clock is ticking, but we still have time to salvage a solid week or two of real winter in there somewhere. 

[Carvers Gap]

Fortunately for TRI, the much advertised much AN torch is over.  TRI sits at +9.7 and that includes a -11 day yesterday.  Impressively, TRI had one +32 day!  Looks like upcoming highs will now be more run-of-the-mill Nino AN stuff.  Highs will be in the 50s here with lows in the 30s.   Before I make this slip-up again, I actually don't think this winter will be classified as a weak Nino.  It will likely be a Nada.  The overall ENSO is weakly positive for sure but not Nino level.  Some regions are not even close.  I slip up often and call it a weak Nino, but in reality...it is not.  And La Nada winters here are not productive as a general rule IMBY.  We actually need a stronger driver from an ENSO standpoint, but not too strong.  My preferred winter pattern is a weak La Nina by a long shot, because I like cold.  If you like BIG winter storms, the pattern we are in has some of those elements - just not nickel and dime stuff that makes it feel like winter.  I have definitely been through worse winters.  

One winter during the early 80s, we had just moved back from Florida.  We had a super cold December.  I remember the inside of the car windows freezing up while the heater was on.  We got very little snow.  The one really good storm that we had was followed by rain which washed it away right as the snow ended.  Man, that was the worst.  When I was at UT during the early 90s, I was walking around in t-shirts during January and February.  The late 90s were absolutely the worst though, minus some fluke big storms.  So far, this winter reminds me of those late 90s winters.  But it isn't over yet.

Overall, I think we will look back at the severe event from two weekends ago as the demarcation point for when the pattern changed.  Now, the new pattern may not be much better than the old pattern, but it is not worse - yet!  Yesterday, we had a high of 26.  Today was slightly warmer.  We have received light snow both days.  Nothing appreciable but made if feel like winter.  Next couple of weeks will be textbook Nino stuff with BN height sneaking into the SE from time to time.  Maybe we score a storm.  Maybe we don't.  That HB high is going to keep sending storms south.  If any modeling misses a cold front, look out.

So that gets us to Feb 5th.  What then?  10 million dollar question.  Verbatim, looks like a substantial pattern shift and maybe another step down.  We do know that modeling has universally been mistaken with this look already this winter.  What is interesting is that modeling had incredible cold, lost it, and now has it again but about two weeks later.  I am not an optimist by nature, but pretty much a realist with a touch of idealism.  I generally just call it as I see it which is one reason I pulled the plug on my optimism last week.  That Thursday run of the EPS was such a change, I knew the rest of January was toast in terms of temps.  The EPS continues to call for a decent pattern in a couple of weeks.  Both the GEFS and GFS have something similar.  Target time frame would be Feb 5th.  If that date keeps getting pushed back, we know something is up.  I wouldn't be surprised to see it pushed back a couple of days, but more than that and we know the drill.  It is on the table that the same step-down pattern from October could be occurring with a final flip.  That has precedent.   It is also possible that we get another head fake and the rest of winter is just a dud.  For either of those scenarios, it won't we the first time and it won't be the last time.  As of today, I am encouraged by the pattern ahead.  Maybe LR guidance can score the win this time.  A big factor in our favor is February and November both feature a change of seasons and that has a tendency to change things up.  Last year is an example of when that did not happen.   

[Carvers Gap]

Was digging around and looking at 1954-1955 data which I think will prove to be a legitimate analog for this winter w some slight adjustment for a slightly warmer climate.  It featured an early snowfall in November and not much in December.  Looks like December was a good month followed by less during February.  What that tells me is that winter had a good, but narrow window for winter weather.  Reference is pg 72 of the document linked below.  

Kingsport 54-55 Snowfall Data by month and season

 

[BhamParker]

18z GFS looks more bullish than it has in several runs with the NW flow.

[Holston_River_Rambler]

Just now, BhamParker said:

18z GFS looks more bullish than it has in several runs with the NW flow.

Not sure what wiggle room you have, but if it was me and no concerns about the time,  I'd wait until it gets into the Mesoscale models' range. Just don't believe the 3km NAM when it dumps 40 inches on Leconte, lol. 

Like Carver's said it is a touchy setup and still time for it to go either way. The folks over in the Foothills and Mts SE forum still seem keen on it. 

[John1122]

49 minutes ago, BhamParker said:

18z GFS looks more bullish than it has in several runs with the NW flow.

Do you know the elevation of the cabin you're staying at? It makes a huge difference in upslope events in the Smokies and foothills in regards to seeing snow flurries and showers vs a long duration event with accumulation. 

LeConte is in a world unto itself in those events as well.  It's the premiere upslope location in the entire southern Apps.  Sometimes models can bleed snow over onto areas it might not quite happen at because their resolution isn't quite high enough.  Especially globals. But the higher up you're staying the better chance of seeing snow and accumulation. 

[BhamParker]

4 minutes ago, John1122 said:

Do you know the elevation of the cabin you're staying at? It makes a huge difference in upslope events in the Smokies and foothills in regards to seeing snow flurries and showers vs a long duration event with accumulation. 

LeConte is in a world unto itself in those events as well.  It's the premiere upslope location in the entire southern Apps.  Sometimes models can bleed snow over onto areas it might not quite happen at because their resolution isn't quite high enough.  Especially globals. But the higher up you're staying the better chance of seeing snow and accumulation. 

The cabin is just over 2,600 feet. I’ve stayed in a few cabins around 2500 sq feet and they seemed to do okay in the past. I tried to find one as high as I could. 

[Carvers Gap]

1 hour ago, BhamParker said:

The cabin is just over 2,600 feet. I’ve stayed in a few cabins around 2500 sq feet and they seemed to do okay in the past. I tried to find one as high as I could. 

Bham, if we get snow out of this, we may just pay to move you up here each winter.  

[BhamParker]

16 minutes ago, Carvers Gap said:

Bham, if we get snow out of this, we may just pay to move you up here each winter.  

 

Lol, I sure hope it happens. I did notice the GEFS now has all members with some sort of snow falling. I'll be hanging onto this one as long as I can. I will never forget staying up in a cabin Christmas of 2010 in wears valley. It rained most of the morning, but then changed over to a wet snow and we received 1-2 inches but it did not stick to the streets or anything. I remember staying up that night thinking it was over and the snow started falling and it snowed most of the night that night with temps well below freezing. I woke up the next morning and we probably had 5-6 inches of snow and it stuck to everything. It was amazing. I remember looking at the radar and the snow literally was just lined up along the mountains and nowhere else. I am guessing it was a true NW flow snow that night and I never will forget it. I am sure many of you remember the Christmas 2010 snow. I know that this is nothing like that, but I would just be thrilled to see things get white up and around our cabin. This will be the 5th time I have chased the snow up there and I have never been truly shutout. One time I only received about .5 inch, but it was still pretty.

 

The other big dog I chased was January 23, 2016 and we probably got 6-8 inches during that one and it was awesome.

 

I felt like I jumped the gun a little early after 00z Monday, but I won't go down without a fight. I will be here to share it with you fellow mountain guys win or lose.

 

 

[PowellVolz]

The cabin is just over 2,600 feet. I’ve stayed in a few cabins around 2500 sq feet and they seemed to do okay in the past. I tried to find one as high as I could. 

Not sure what location you’re going to but in Wears Valley I’ve stayed at a couple of cabins that are 3k+. One of them was right on the GSM line.


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[BhamParker]

11 minutes ago, PowellVolz said:

 

Not sure what location you’re going to but in Wears Valley I’ve stayed at a couple of cabins that are 3k+. One of them was right on the GSM line.

 

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This one is off Ski Mountain road near Ober Gatlinburg, right by Cove mountain. We stayed right near here in Feb of 2018 the weekend of the super bowl and picked up 2 inches while most of the areas below me didn't receive a thing. 

[tennvolfan]

I wish you hadn't mentioned 13-14 and 14-15. I've tried to banish them from my memory. That was a great time to bust out of the long term snow drought, but SW and most of middle TN managed to screw up even in those cold years with some great patterns. 

Agreed on the wait and see for February. The clock is ticking, but we still have time to salvage a solid week or two of real winter in there somewhere. 

 

Living in the north Memphis metro( and it’s been different than the North MS burbs) the last 2 decades were far better than the 90’s. I’ve noticed an overall uptick in late winter events around here. Feb 28, 2009 (insane ULL), March 7-8, 2008 (near blizzard conditions), March 3 2014 (huge sleet storm that split Memphis in half and brutal cold temps for March), and of course maybe my favorite of the decade- March 4 2015 with an inch of sleet and 4-6 of snow. Keep in mind- none of these years had a significant winter storm in those January’s. (January 2018 was really decent here too.) Pre 2000, I would never have believed that late winter would produce without producing in January- but it appears it’s more likely now. I can’t find any records in this area (until the last 2 decades) that late winter events happened after nothing earlier. Maybe it’s a new precedent in this late phase positive AMO. I think the AMO needs to flip to see where the cards fall. We are nearly 25 years into the positive phase so it’s time is limited.