TIMS model verification, December 31, 2021 - January 3, 2022

[Holston_River_Rambler]

We're turning this into the TIMS thread. Thunder in the mountains model? Can it equal snow afterwards? If so, does severe weather = heavier snow? We'll know by January 3rd, lol.

[John1122]

Expecting snow showers/flurries. I'd be overjoyed at this point to even get the inch or so the Canadian suite is advertising. 

[Holston_River_Rambler]

Will the Eastman Bubble rob Hawkins county? Does the 18z GFS on 12/30 know something we don't? Will Hooker connect with Tillman again in the second half? Time will tell. 

[Holston_River_Rambler]

1 minute ago, John1122 said:

Expecting snow showers/flurries. I'd be overjoyed at this point to even get the inch or so the Canadian suite is advertising. 

This is def. one where I think ground temps will play a role. Couple hours of moderate snow would be a win IMBY. 

[John1122]

Our odd quarter offense is like a happy hour NAM run at 60 hours. It goes fast and goes big. I expect two or three big runs from it the GFS from now til early Saturday then we will either see all modeling on board or the collapse into a regular frontal passage. 

[Windspeed]

Even an dusting would be a total win at this point as the Valley has had big nothing so far this season.

[Carvers Gap]

While the Vols were getting the shaft, MRX has issued this statement about Sunday night.  Gives a bit of credence to our discussion I think.  

 

 

[jaxjagman]

why dont yall just make this a thread from new years eve until out,it seems quite a period that way i wont start a severe thread.

[John1122]

The GFS looks more what I expect. I believe the NAM is out to lunch. RGEM is probably the best for us all at this point. Still hoping to see the flakes flying for only the 2nd time this winter. 

It's tough all over though. LeConte has 1.1 inches this snow season. They normally have recorded around 3 feet by now. 

[John1122]

GGem isn't bad for most of us and the Euro got slightly better too. Not sure how much will stick but a lot of us should see some flakes Sunday and Sunday night. 

[jaxjagman]

Models are looking more NAM,should be a enhanced severe risk coming up some where

[jaxjagman]

Speak of the dog

[yoda]

4 minutes ago, jaxjagman said:

Speak of the dog

Nothing says Happy New Year than a large 10% hatched tor prob

[yoda]

Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1254 AM CST Fri Dec 31 2021

   Valid 011200Z - 021200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF THE DEEP SOUTH AND TENNESSEE VALLEY....

   ...SUMMARY...
   Widespread thunderstorms are expected from the ArkLaTex to the
   Western Appalachians on New Year's Day. All severe-weather hazards
   are possible including large hail, damaging winds, and tornadoes, a
   couple of which may be strong.

   ...Synopsis...
   A positively tilted upper-level trough will be centered near the
   Great Basin to start the period. This trough will maintain its
   positive tilt as it shifts eastward across the Plains and into the
   Midwest by 12Z Sunday. An embedded mid-level shortwave trough will
   move quickly from the southern High Plains across the Midwest and
   Ohio Valley Saturday to the Northeast by Sunday morning. A surface
   reflection of this mid-level shortwave trough is expected to travel
   along the front from the Ozarks to the Ohio Valley and into the
   Mid-Atlantic.

   ...Ohio Valley into the central Appalachians...
   There is still considerable uncertainty regarding the northward
   extent of the destabilization and severe-weather threat based on the
   position of the position of the surface front and the strength of
   the surface low. The NAM is stronger with the surface low with a
   much farther north warm front bringing low 60s dewpoints north of
   the Ohio River into southern Illinois, southern Indiana, and
   Southwest Ohio. However, the operational GFS is much weaker and
   southeast with the surface low and only brings low 60s dewpoints
   into south-central Kentucky. The ECMWF solution is between these two
   locations with the frontal position, which also closely resembles
   the GEFS mean. Therefore, the northern extent of the marginal and
   slight risk threat areas match the ECMWF and GEFS mean. 

   A line of storms is expected to move through this region during the
   afternoon and early evening hours. Forecast soundings show more than
   50 knots of flow only a few hundred meters above the surface.
   Therefore, mixing this strong flow to the surface should not be that
   difficult, even in a weak buoyancy environment. Low 60s dewpoints
   should yield MLCAPE around 250 to 500 J/kg across southern Kentucky,
   which increases the confidence for severe winds as the squall line
   moves through. In addition, a QLCS tornado threat will exist given
   the strong low-level speed shear present ahead of this line of
   storms. However, the limited instability and veered surface flow
   will be limiting factors to a greater tornado threat along this
   portion of the line. 

   ...Portions of the Deep South into the Tennessee Valley...
   A large area of thunderstorms, some of which may be severe, is
   expected to be ongoing from western Kentucky to northern Texas
   Saturday morning. As the surface low moves from the Plains into the
   Ozarks Saturday morning, this convection is expected to become
   better organized, likely into a squall line, and start to advance
   eastward. Dewpoints are forecast in the mid to upper 60s ahead of
   these storms, which should yield MLCAPE around 500 to 1500 J/kg from
   north to south. This should be more than sufficient to maintain a
   strong squall line through the afternoon and into the overnight
   hours across eastern Arkansas, most of Tennessee, and northern
   Mississippi and Alabama. A 50 to 60 knot low-level jet will result
   in strong low-level speed shear across the entire warm sector.
   Forecast soundings show mostly unidirectional flow in the lowest 1
   km due to the veered surface flow across most of the warm sector as
   a result of the elongated nature of the surface pressure pattern.
   This should temper the tornado threat somewhat, but with the strong
   speed shear and the expectation of a well balanced squall line, the
   environment will still be supportive for QLCS tornadoes. 

   Most guidance hints at the potential for some warm sector supercell
   development across portions of Mississippi, Alabama, and Tennessee
   Saturday afternoon/evening. The ECMWF has been especially bullish
   with pre-frontal convection for the last several days, which
   continues through the latest 00Z run. Any strong supercells which
   can develop in the open warm sector will likely have the greatest
   threat for significant to potentially intense tornadoes. The most
   likely region for pre-frontal supercell development will be from
   eastern Arkansas to northern Alabama and possibly southern Tennessee
   where greater instability is forecast. Veered low-level flow will
   keep low-level directional shear limited during the first half of
   the day. However, at least slightly greater low-level turning is
   shown by forecast soundings during the late afternoon into the
   evening hours as surface flow remains south-southwest, while the
   low-level jet starts to veer more westerly as the main wave shifts
   east. This may result in a slightly higher tornado threat into the
   overnight hours from far eastern Mississippi into northern/central
   Alabama and northwest Georgia.

   ..Bentley.. 12/31/2021

6 minutes ago, jaxjagman said:

Speak of the dog

Nothing says Happy New Year than a large 10% hatched tor prob

[John1122]

The RGEM was about as good as it can get for about as much of the forum as possible.

[Holston_River_Rambler]

By popular demand I went ahead and updated the title and initial description post for this thread. 

 

 

[Holston_River_Rambler]

6z Euro looks the best I've seen it look with the energy for the wintrier threats with this system:

 

I don't have the precip type maps yet, but here is the 6 hr accum. precip

 

[*Flash*]

Waking up this morning to another hatched tornado threat within an Enhanced Risk. *Sigh* For once, I'm fed up with having to track another severe weather threat. Per my last post, I just dodged a bullet. Looks like our RVA will have to go back to channeling our inner Neo from the Matrix. Seriously, does anyone recall the last time we had this substantial severe threat following by accumulating snows within 48 hours? FWIW, here are the SREF Plums for BNA. Coming in a bit more juicy. NWS-Nash is more bullish for the usual higher elevations east of town which to me is the sensible play at this point. Talk about 2022 coming in like a lion. Sheesh...

[Holston_River_Rambler]

NAM was pretty flat with the energy for the wintry threats at 12z, but the RGEM was still looking pretty stout:

 

 

 

[Holston_River_Rambler]

@Carvers Gap

 

[Holston_River_Rambler]

Really nice vort pass for eastern areas on the 12z GFS:

 

 

[fountainguy97]

2 minutes ago, Holston_River_Rambler said:

Really nice vort pass for eastern areas on the 12z GFS:

 

man that band wrapping up around a 999mb low would be crazy. 

[Carvers Gap]

35 minutes ago, Holston_River_Rambler said:

@Carvers Gap

 

I got 6" of snow on that run.  Must be a heckuva SE wind on the run!!!

 

16 minutes ago, Holston_River_Rambler said:

Really nice vort pass for eastern areas on the 12z GFS:

 

 

Legit might be a good day to head to Roan Mountain. 

[Carvers Gap]

I can't see the precip type map yet, by the 12z CMC has a robust low now in the Piedmont for Jan 3.  Good look.

[tnweathernut]

Apparently the 12z RGEM just said if the NAM won't NAM them, guess I will have to do it myself....  lol

[John1122]

Canadian was good area wide.

 

[Holston_River_Rambler]

12z Euro is deeper and slower with the energy than its 0z run as it crosses the southeast. 

[Holston_River_Rambler]

Still not as nice as the GFS, but better:

 

[Holston_River_Rambler]

Pretty detailed disco by Webb and Masiello re: our little vort max:

Some of y'all have probably seen the first coupe of tweets this pulls up, but some of the later replies get interesting. 

TL/DR: could be a last minute NW trend as it starts to unfold. 

[Holston_River_Rambler]

I can’t bring myself to post it but if you want to see a true weenie run, check out the latest SREF-ARW that Ollie Williams posted over on Southernwx. Credit to him for finding it!