1/10-1/12 Southern Slider

[Kasper]

4 minutes ago, Hurricaneguy said:

True, but when you've been deprived seeing a good >5" snow event at your house in over ten years it gets old. Last year broke me lol

[Kasper]

5 minutes ago, Carvers Gap said:

Here is a more zoomed in version of the gfs:

[Carvers Gap]

12z CMC

[John1122]

The NAM is a Plateau runner. 

It's builds a stronger high by a smidgen and cuts the lp up the Plateau. 

I knew the HRRR would be big when the RAP was. 

[Carvers Gap]

Speaking of the 12z HRRR...

[jaxjagman]

GFS shows a heavy band of snow tomorrow setting up from SW/TN.Mid Tn into east TN,VA after,if it right anyways

[Reb]

RAP smokes the valley

[John1122]

Hi-Res models can really overemphasize terrain features at times. Their resolution is extremely high and sees them all clearly and will really lean into them. They show huge downsloping off Cross Mountain here frequently and I've never seen it verify to the extent hi-res models do. 

[John1122]

I'll also add this, the wpc noted there would be areas where heavy banding would set up that just can't be seen by models at range. 

[nrgjeff]

View from 30,000 FT or say the good ol' 1000-500mb thickness, models improved overnight 06Z and now 12Z rolling out. Chatty was looking bad above 546 and close to 552 but now its 546 with several hours of 543. While 540 helps me sleep better, 543 could work if cold is in place. All the above should help the Downslope areas too.

Partial thickness looks better too. That 850-700 mb level that was way too warm a couple 18-00Z runs has improved. It's still a little warm, and I'd feel better lower, but it'll work. Plus the true DGZ just above it should be golden. 850 and surface Ts are pretty much available everywhere and self-evident, mostly good.

I think the snow charts rolling off also speak for themselves. Forecast has improved. MRX already raised Chattanooga from that 1" propaganda to a more reasonable 2-3 inches. Honestly that's what I think given current data. If we get more cooling at the low levels we could still get 4+ here. Then I think many areas will score 6 inches just south of I-40. Questions linger south of I-81 just like in CHA.

Like John says, heavy bands will determine a lot too. Cautious optimism has returned. I didn't post it, but I was actually worried last night. This morning I believe everything is on track!

[tnweathernut]

19 minutes ago, Hurricaneguy said:

True, but when you've been deprived seeing a good >5" snow event at your house in over ten years it gets old. Last year broke me lol

I get it.  Our snow holes seem to be related.  lol

[Carvers Gap]

2 minutes ago, John1122 said:

I'll also add this, the wpc noted there would be areas where heavy banding would set up that just can't be seen by models at range. 

Heavy banding!  My favorite post of the day.  

[Math/Met]

18 minutes ago, Hurricaneguy said:

True, but when you've been deprived seeing a good >5" snow event at your house in over ten years it gets old. Last year broke me lol

There are definitely parts of Greene Co that struggle with getting a good snow. I used to live in one of those areas. Areas on the eastern half do better on average. I've had a few snows in the last decade over 5 inches. Last year was definitely not fun though.

[Windspeed]

There is a modeled snow hole over upper NE Holston Valley for a reason, which is likely due to some downslopping with the 850 flow *IF* the SLP cuts across the Southern Apps. Notable with the adjacent to high ridges of Unaka in Greene and Washington Counties, and Sullivan with Holston Mountain. I'm thinking it may very well stump totals versus the western NE TN counties, but I don't forsee graupel or sleet taking over due to warm nose. It should remain cold enough for snow, just weaker overall totals. That being said, if the SLP remains further south, upper NE Tennessee and KTRI may exceed 3-5". But if we land in the middle ground and end up with 4 inches, I am proclaiming this a big win, all things considered. Someone is likely to still get hammered, and I feel like portions of SW VA, such as Gate City to Abingdon, are being under modeled. It would not surprise me to see those places end up with 6-8 inches of powder. Also, I know we post the Icon but take it far less seriously than the GFS, ECMWF and Euro suites, but it is interesting it keeps wanting to pump higher totals over the upper NE Holston watershed this late in the game.

[nrgjeff]

Heavy banding will be the driver this storm. No real TROWAL this set-up. The front WAA and isentropic uplift should be the main thumper. Just not too much NAM. Keep WAA just right. 

That said some areas up near TRI that might miss the front end have a chance upslope. Maybe not a back side trowal, but regular upslope. 

PS that's still close enough for a TROWAL cartoon though. 

4 minutes ago, Carvers Gap said:

Heavy banding!  My favorite post of the day.  

 

[Carvers Gap]

22 minutes ago, Windspeed said:

There is a modeled snow hole over upper NE Holston Valley for a reason, which is likely due to some downslopping with the 850 flow *IF* the SLP cuts across the Southern Apps. Notable with the adjacent to high ridges of Unaka in Greene and Washington Counties, and Sullivan with Holston Mountains. I'm thinking it may very well stump totals versus the western NE TN counties, but I don't forsee graupel or sleet taking over due to warm nose. It should remain cold enough for snow, just weaker overall totals. That being said, if the SLP remains further south, upper NW Tennessee and KTRI may exceed 3-5"s. But if we land in the middle ground and end up with 4 inches. I am proclaiming this a big win, all things considered. Someone is likely to still get hammered, and I feel like portions of SW VA, such as Gate City to Abingdon, are being under modeled. It would not surprise me to see those places end up with 6-8 inches of powder. Also, I know we post the Icon but take it far less seriously than the GFS, ECMWF ans Euro suites, but it is interesting it keeps wanting to pump higher totals over the upper NE Holston watershed this late in the game.

Yeah, I definitely watch those last minute trends.  The ICON is often the lower accumulation model when compared to other modeling for IMBY. So, when it bumps up...I take notice.  Someone asked me a couple of days ago for Kingsport.  I said 3-4" as a conservative estimate.  I think some of the usual places in TRI could go +5.  Some modeling has been placing NE TN under a heaving band as it exits.  As you know, that is not an uncommon feature.  We usually pack on another 1-2" of snow as those bands turn and come out of the Northwest.  We may not get it all from the slider, but I do think some areas will even things up with those bands that will form as it exits.  With the ground already so cold, we are at an advantage that we usually don't have.  Good post.  NE TN is complicated as usual.

[TellicoWx]

9 minutes ago, nrgjeff said:

Heavy banding will be the driver this storm. No real TROWAL this set-up. The front WAA and isentropic uplift should be the main thumper. Just not too much NAM. Keep WAA just right. 

That said some areas up near TRI that might miss the front end have a chance upslope. Maybe not a back side trowal, but regular upslope. 

PS that's still close enough for a TROWAL cartoon though. 

 

Kinda be my thought for awhile...just enough warming to assist in rates, but not cause the mix issue

[fountainguy97]

Reports of Dallas, TX getting snow. Time to watch these cities on the edge of the cold and see how the high res verifies

[ShawnEastTN]

Last night I was 14 degrees, that was after a daytime high of 29.  Models aside, it's really hard for me to think of any scenarios in my ~40 years of life in East Tennessee where a storm moving into this type of deep freeze was a bust warm.  Just anecdotally of course but just can't recall getting busted warm in this type of conditions leading up to a winter storm.  The only busts I can recall in this type of conditions before a storm is dry air and virga storm, and that doesn't really seem plausible.

[nrgjeff]

Yeah Shawn I think that's why we're getting away with high 1000-500mb thickness.

Dallas staying all snow would boost confidence here in 546 thickness land.

[Holston_River_Rambler]

Yeah if you are on X check out the NWS Norman posts. 
 

https://x.com/nwsnorman/status/1877394302462210560?s=46&t=KMZWtmm9xSWkLJtvZXn39g
 

 

[TellicoWx]

Something @Carvers Gapside by side of 12 vs 6 GFS...seems as the event gets now time out west, the totals slowly increase all the way to lead up so far (for their area)

[John1122]

Perhaps the NAM can't get the Plateau cutter out of it's system until PowellVolz arrives.

[Carvers Gap]

1 minute ago, John1122 said:

Perhaps the NAM can't get the Plateau cutter out of it's system until PowellVolz arrives.

@PowellVolz, you up and running. Sound check! 

[bearman]

8 minutes ago, fountainguy97 said:

Reports of Dallas, TX getting snow. Time to watch these cities on the edge of the cold and see how the high res verifies

Heavy snow squalls moving through Dallas.  My Father for what its worth always said If Dallas gets snow we are next so its always a positive thing in my head.

[fountainguy97]

Hrrr trend for TX

[Runman292]

Ladies and Gentlemen, MRX has finally joined the chat: All watches have been upgraded to warnings.

 

[TellicoWx]

Ukie buries Memphis with a foot

[ShawnEastTN]

9 minutes ago, Runman292 said:

Ladies and Gentlemen, MRX has finally joined the chat: All watches have been upgraded to warnings.

 

They've split the warnings into 3 sectors it appears.  Far southern valley, mountain county portions like "Southeast Monroe" & "Smoky Mountain" and the rest of the cwa all with differing forecast and amounts.

[Windspeed]

Ladies and Gentlemen, MRX has finally joined the chat: All watches have been upgraded to warnings.
 

https://forecast.weather.gov/showsigwx.php?warnzone=TNZ040&warncounty=TNC029&firewxzone=TNZ040&local_place1=3%20Miles%20SE%20Lowland%20TN&product1=Winter+Storm+Warning&lat=36.1242&lon=-83.1732