December 2022 Medium/Long Range Pattern Discussion Thread

[Holston_River_Rambler]

I'll call that a step in the right direction for the Euro:

 

 

[Carvers Gap]

28 minutes ago, Holston_River_Rambler said:

I'll call that a step in the right direction for the Euro:

 

 

Memphis is 40 degrees colder on the 23rd.  LOL - quite the correction.   Interestingly, the GEPS is flirting with a Miller A on the ensemble.  It is not quite there, but it pops a low on the cold front of the 23rd.

[Carvers Gap]

Dare I mention this(I may regret it).  The LR does not feature a breakdown of this upcoming pattern anytime soon.   The CFSv2 seasonal this morning keeps the pattern through January w/ maybe a slight relaxation away from the extreme cold.  Moderation would be returning to normal.  I suspect we see a Chinook in Canada scour some cold out there while keeping a similar set-up to 500, and then it reloads mid-Jan(kind of fits Cosgrove's ideas).  When the NAO weakens, the PNA gets stronger...and when he PNA weakens, the NAO gets stronger.  We are long overdue for a cold winter.  Could it be this year?   IDK, but it might be on the table.  That goes against my own winter ideas, but third year La Ninas (I think) have some clusters of winters which held on.......

[Daniel Boone]

4 hours ago, Carvers Gap said:

Dare I mention this(I may regret it).  The LR does not feature a breakdown of this upcoming pattern anytime soon.   The CFSv2 seasonal this morning keeps the pattern through January w/ maybe a slight relaxation away from the extreme cold.  Moderation would be returning to normal.  I suspect we see a Chinook in Canada scour some cold out there while keeping a similar set-up to 500, and then it reloads mid-Jan(kind of fits Cosgrove's ideas).  When the NAO weakens, the PNA gets stronger...and when he PNA weakens, the NAO gets stronger.  We are long overdue for a cold winter.  Could it be this year?   IDK, but it might be on the table.  That goes against my own winter ideas, but third year La Ninas (I think) have some clusters of winters which held on.......

Actually makes sense the way the cold Nina Winter's progressed.  There were the breaks , of which snow would melt assisted with rain and flooding for short intervals, only to turn back to cold and snow.  You're right on with the Chinook Carver's. That was a part of the evolution in those Winter's. 

     I'm still not sold on that this Winter however as so far the Nina ( cold west, mild east) pattern has won out this late fall/Winter. 3 weeks cold west vs week to 10 days east. Also, those cold eastern Nina Winter's pretty much all started earlier with the base cold pattern. Not really sure that means much , really though. 

     On a positive note, the blocking that has shown up may help in getting that rare colder eastern Winter. MJO should help later on I think as SST'S become more favorable in critical area's. 

     

[Stovepipe]

15 hours ago, PowellVolz said:

I had 6.5” at my house and just a few miles down the road had 2-3”. Crazy stuff but that’s how it is living in Knox Co.


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No kiddin.  I recently moved to Halls from west Knox and have already documented significant differences in temps and precip nestled between Black Oak Ridge and Beaver Ridge.  Hoping to see more flakes this year (although last season wasn't bad out west).

[John1122]

The 12z suite is coming in cold and the snow was back to some extent on the GFS and the Canadian is all in.

[Bigbald]

Man that Canadian run 

[Bigbald]

Should be some high ratio northwest flow at the very end for northeast tn/sw va.

[Holston_River_Rambler]

12z Euro looking like a compromise between the 12z GFS and 12z CMC at 500 mb.

 

 

[John1122]

The Euro is still not where we'd like it to be, but it's slow to get on board over the last few years, on systems like this. We've had a few nice anafrontal events including the 2020 Christmas eve snow, that the GFS spotted first.

[Carvers Gap]

At 10 days out, lots of room for multiple changes.  That said, cold is likely going to be in place.  Precip has increased of late - it is raining today and less drought.  Drought seems to begat drought.  Good to see that waning.  Northern stream clippers are likely to be missed.  Lots of wiggle room right now.

[tnweathernut]

35 minutes ago, Carvers Gap said:

At 10 days out, lots of room for multiple changes.  That said, cold is likely going to be in place.  Precip has increased of late - it is raining today and less drought.  Drought seems to begat drought.  Good to see that waning.  Northern stream clippers are likely to be missed.  Lots of wiggle room right now.

The biggest unknown (i.e. wildcard) IMO is the energy traversing the northern gulf of Mexico around days 6-8 and how it interacts with the northern stream energy once near/off the SE coast.  The modeling is keying on a piece of southern energy being captured around FL to off the east coast and pulled northward .  IF (big if, but time for modeling to miss significantly for better or worse) the piece of energy captured is in the northern gulf vs the FL/SE coastline, it changes how things play out.  As shown on the CMC and Euro, the wavelengths are just a bit off..........  but it's close enough to keep me interested.

Also, like mentioned...........  there's possibly an imbedded northern stream piece of energy somewhere that may show up once the cold is established.

[snowmaker]

1 hour ago, tnweathernut said:

The biggest unknown (i.e. wildcard) IMO is the energy traversing the northern gulf of Mexico around days 6-8 and how it interacts with the northern stream energy once near/off the SE coast.  The modeling is keying on a piece of southern energy being captured around FL to off the east coast and pulled northward .  IF (big if, but time for modeling to miss significantly for better or worse) the piece of energy captured is in the northern gulf vs the FL/SE coastline, it changes how things play out.  As shown on the CMC and Euro, the wavelengths are just a bit off..........  but it's close enough to keep me interested.

Also, like mentioned...........  there's possibly an imbedded northern stream piece of energy somewhere that may show up once the cold is established.

It seemed to me that wave on the 19th-20 tried even a little harder to stay together this time. At least it did to my untrained eye. The rest of the 18z GFS looked like a cold dry whiff. But it will probably change next time. Euro and Canadian seemed to have the 22-23rd system at 12z.

[Wurbus]

That was one cold GFS run. East TN below freezing from the 23rd-29th if that verifies.

[Matthew70]

1 hour ago, Wurbus said:

That was one cold GFS run. East TN below freezing from the 23rd-29th if that verifies.

Let’s just hope snow is on the ground instead of brown & dry. 

[Itryatgolf70]

Still my concern is cold but dry due to no sw flow. Maybe that changes in January. Stay optimistic 

[Jed33]

3 hours ago, Wurbus said:

That was one cold GFS run. East TN below freezing from the 23rd-29th if that verifies.

On that 18z GFS run, sub 500mb thicknesses creep into NE TN at around 1AM on Christmas Day! It’s not very often you will see that even modeled for our area!

[Daniel Boone]

49 minutes ago, Jed33 said:

On that 18z GFS run, sub 500mb thicknesses creep into NE TN at around 1AM on Christmas Day! It’s not very often you will see that even modeled for our area!

Yeah, shows 1 p.m. Temps Christmas in single digits SWVA/NETN with below zero highest elevations. 

[John1122]

Really nice clipper pass on the 0z for most of the area. Reminds me of the old Siberian express systems that would dump 2-4 inches of snow and rush in extreme cold behind it. The Canadian is almost as snowy, but even colder than the GFS through 210.

[Reb]

2 minutes ago, John1122 said:

Really nice clipper pass on the 0z for most of the area. Reminds me of the old Siberian express systems that would dump 2-4 inches of snow and rush in extreme cold behind it. The Canadian is almost as snowy, but even colder than the GFS through 210.

GFS and CMC phase that clipper just as it passes us to the east. Sure would be nice to see that phase a hair sooner

[John1122]

Wild, wound up storm on the Euro. Wraps in incredible cold and snowy weather across the region. 

[Matthew70]

2 minutes ago, John1122 said:

Wild, wound up storm on the Euro. Wraps in incredible cold and snowy weather across the region. 

We need some white on ground if it’s going to be this cold!  

[John1122]

1 minute ago, Matthew70 said:

We need some white on ground if it’s going to be this cold!  

I think we will get it in this pattern. It's rare to get such a potent front to move through that doesn't at least bring some snow with it. 

[fountainguy97]

Idk if it's the perfect flow or what but this is one of the most intense wind events I've experienced here. It's legitimate mid range tropical storm conditions here.

 

The 00z Euro would be wild. Near zero with NW flow and possible blizzard level winds. 

[Holston_River_Rambler]

Here's the magical overnight Euro run:

That sucker is a hair's breadth from being a mythical storm. Scenario:

SE ridge flexes just enough to make the initial vort amp a bit more as it moves over the NW Gulf. PNA ridge pumps up enough to push the main vort, essentially a TPV lobe, on a track that pushes it from KS --> OK --> Louisiana. That baroclinic zone would make a storm that we would never forget.

As it stands, here is the pretty output from last nights run:

 

Wind chills:

 

Kuchera snowfall:

 

Of course the Euro has, over the past couple of years since its most recent upgrades, tended to overamp storms at this range. 

6z GFS OP is basically a non event aside from a few flurries. 

0z EPS support the idea of at least som snow for plateau areas to the east:

as do the 0z GEFS members:

 

 

 

[Carvers Gap]

Morning message:  We ride with the 0z Euro.

[PowellVolz]

No kiddin.  I recently moved to Halls from west Knox and have already documented significant differences in temps and precip nestled between Black Oak Ridge and Beaver Ridge.  Hoping to see more flakes this year (although last season wasn't bad out west).

Where are you living now? After you cross Black Oak Ridge into Halls for whatever reason it’s like going into a different county. I’m on Emory close to the HS behind CVS. It’s on average 7-8° colder at my house than in Knoxville.


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[PowellVolz]

Still my concern is cold but dry due to no sw flow. Maybe that changes in January. Stay optimistic 

It’s crazy how places that see feet of snow each year doesn’t have a GOM to feed them but when it gets in the 20’s here it’s too cold and dry. Canada has DP’s in the single digits with a ongoing blizzard.


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[Looking to the skies]

I hate the GFS. May Matilda put it to Eternal rest

[Daniel Boone]

1 hour ago, PowellVolz said:

It’s crazy how places that see feet of snow each year doesn’t have a GOM to feed them but when it gets in the 20’s here it’s too cold and dry. Canada has DP’s in the single digits with a ongoing blizzard.


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Yep. Causes us so much anguish. It is depressing when you get rounds of precip when it's mild and when it finally gets cold, dry as a bone. That's the good thing about El ninos; usually systems trekking along the subtropical Jet during mild and cold periods.