February 11-13 ULL event

[fountainguy97]

RGEM is king. 

[tnweathernut]

3 minutes ago, fountainguy97 said:

RGEM is king. 

And the solution is poo for snow lovers. lol

[Silas Lang]

LOL not the trends we want to see. Looking like a bone chilling rain for a lot of us with the exception of places on the Plateau and mountains. And even then totals have pulled way back. 

[Greyhound]

Based on all the Nostradamus Facebook Weather Forecasters…….grocery stores should get hard.

[Daniel Boone]

1 hour ago, fountainguy97 said:

RGEM is king. 

Yeah' should of adhered to it even though it has been showing what we didn't want to see irt snow.  It has been the best overall SRM for this area the last 3 Winter's.

[fountainguy97]

32 minutes ago, Daniel Boone said:

Yeah' should have adhered to it even though it has been showing what we didn't want to see irt snow.  It has been the best overall SRM for this area the last 3 Winter's.

Tough pill to swallow. It never sat right with me that it was just so different than the rest and didn't budge. The whole cmc family never moved. 
 

should have been the red flag.

[EastTNWeatherAdmirer]

A stupid little poem I wrote: 

With the Upper Level Low

Elevation is key

The higher you go

The more snow will be 

So weatherman be woe

even though big snow maps are to see 

we must say no

[fountainguy97]

1000 mile shift south still wasn't enough lol. 
 

[Holston_River_Rambler]

Where's the facebook meteorologist who types in all CAPS @Greyhound I trust that person's forecasts the most. 

[*Flash*]

4 hours ago, Uncle Nasty said:

I say take them to Chattanooga. What could possibly go wrong in our area?

Sent from my moto z4 using Tapatalk
 

I'll pass on Chatty for now...but will certainly keep an eye on things. Ideally I wouldn't have to hit any eastern valleys and keep travels confined to the plateau. 

[Holston_River_Rambler]

24 minutes ago, *Flash* said:

I'll pass on Chatty for now...but will certainly keep an eye on things. Ideally I wouldn't have to hit any eastern valleys and keep travels confined to the plateau. 

If you can get up to Black mountain in Crab Orchard, it has nice views and is pretty high up. 

 

[Silas Lang]

Euro took a step back towards snow. 

[Daniel Boone]

2 hours ago, Holston_River_Rambler said:

Where's the facebook meteorologist who types in all CAPS @Greyhound I trust that person's forecasts the most. 

Or that famous dyslexic hothead one, lol

[KnoxLC]

1 hour ago, Silas Lang said:

Euro took a step back towards snow. 

I hope it's a step that still keeps Knoxville in the game? It would be wonderful to have an accumulating snow here to make up a little for an abysmal winter.

[Silas Lang]

22 minutes ago, KnoxLC said:

I hope it's a step that still keeps Knoxville in the game? It would be wonderful to have an accumulating snow here to make up a little for an abysmal winter.

It wasn't a whole lot. Think around an inch or two in most of the valley. Still, a better solution than the rest of modeling at this point. 

[Daniel Boone]

20 minutes ago, Silas Lang said:

It wasn't a whole lot. Think around an inch or two in most of the valley. Still, a better solution than the rest of modeling at this point. 

Yeah, hi-res euro showing decent amounts northern valley and plateau.

[Carvers Gap]

TRI is in the game...for how much longer?  Now, that is a good question.

[Silas Lang]

Pretty good discussion for MRX. They seem to think it will be snow everywhere in the area by Sunday morning, which I found surprising, as the models have been trending mostly rain in the valley. Plateau and Mountains obviously favored for accumulation. 

The mid/upper low will be the main driver of our weather from
Saturday night through Sunday night. Isentropic lift will spread
rain to the area from south to north late Saturday and into the
evening, with a top-down moistening of the column. Evaporative
cooling will initially be offset by an easterly flow with warm
advection and downsloping winds in the Valley. After midnight, the
freezing level drops as the upper low tracks into GA, and
mountain tops should begin to see snow by midnight. Forecast
soundings show a deep layer from the surface up to 700 mb that is
nearly isothermal, from 1-4 degrees above freezing. From 12-15Z,
the top of this layer cools under the upper low, while surface
temps remain several degrees above freezing, and this continues
through Sunday. On the NW side of the circulation, a deformation
zone will set up across Middle TN, and track into KY and WV
through Sunday. Frontogenetic forcing in this area may result in
some heavier precip rates.

Snow accumulations will be highly dependent on temperatures, not
only at the surface but up to 700 mb. In these situations, the
precip rate can make a big difference in how much precip falls as
snow, and how much can accumulate. This makes the forecast highly
uncertain. Snow is expected to be falling nearly everywhere on
Sunday morning, but temperatures in most spots outside the
mountains will be in the mid to upper 30s, making accumulation
difficult. An exception may be where snowfall rates are high
enough to cool temps closer to freezing. As mentioned above, the
favored area for this to occur in a frontogenesis zone near the
Plateau and SW VA. This is the area of lowest confidence.
Confidence is higher that impactful snow amounts will be in the TN
mountains, and that much of the TN Valley will have little to no
accumulation. Based on this reasoning, a Winter Storm Watch will
be issued for the TN mountains from midnight Saturday night to
midnight Sunday night.

 

 

[PowellVolz]

I still believe when dynamics take over this will change to snow and will stay snow for anyone on the NW side. If the temps were right, we would be looking at 8-12” across the valley IMO.


.

[PowellVolz]

TRI is in the game...for how much longer?  Now, that is a good question.

I think you get a thumping


.

[tnweathernut]

Just now, PowellVolz said:

I still believe when dynamics take over this will change to snow and will stay snow for anyone on the NW side. If the temps were right, we would be looking at 8-12” across the valley IMO.


.

The biggest thing I don't like for anyone in east TN is the deform band sets up across the plateau and even into middle Tennessee.  This isn't the way to get a big snow anywhere near the valley in east TN in light of a very marginal temperature profile.  JMO

 

[PowellVolz]

The biggest thing I don't like for anyone in east TN is the deform band sets up across the plateau and even into middle Tennessee.  This isn't the way to get a big snow anywhere near the valley in east TN in light of a very marginal temperature profile.  JMO
 

I agree it’s not ideal but we have what we have. Am I trying to figure out how we can score? Yes. Do I think it’s a long shot? Absolutely not.


.

[Silas Lang]

I don't think any adjustments are off the table just yet either. One small move in the track could lead to more favorable results. Not like we need a huge change. 

[fountainguy97]

21 minutes ago, tnweathernut said:

The biggest thing I don't like for anyone in east TN is the deform band sets up across the plateau and even into middle Tennessee.  This isn't the way to get a big snow anywhere near the valley in east TN in light of a very marginal temperature profile.  JMO

 

Yes I think the issue isn't the temperature more than it's just the deform band has moved west. If you look at simulated radars there is a massive dry slot Sunday.  Rates can never overcome because there simply are no good rates.

[tnweathernut]

53 minutes ago, fountainguy97 said:

Yes I think the issue isn't the temperature more than it's just the deform band has moved west. If you look at simulated radars there is a massive dry slot Sunday.  Rates can never overcome because there simply are no good rates.

Exactly.  This is a big problem for our area. Initially we thought there would be an inverted trough across the southern apps.  I don’t know where that thought has gone?

[Holston_River_Rambler]

WPC still has an inverted trough, but just at a different orientation.

[Holston_River_Rambler]

I think its just "see where everything sets up" time. 

[Holston_River_Rambler]

WPC has a disco about the potential as well I just noticed:

Probabilistic Heavy Snow and Icing Discussion

NWS Weather Prediction Center College Park MD

152 PM EST Fri Feb 10 2023

 

Valid 00Z Sat Feb 11 2023 - 00Z Tue Feb 14 2023

 

 

...Southern Appalachians...

Days 2-3...

 

Difficult forecast Sunday into Monday as an intense closed and

vertically stacked mid-level low ejects slowly across the

Southeast before lifting off the North Carolina coast Monday

morning /D3/. As this trough advects to the east, a trailing

subtropical jet streak will strengthen along the Gulf Coast

providing favorable LFQ diffluence over the Southeast, resulting

in impressive synoptic layer ascent across much of the area. As

this evolution occurs, moisture advection will intensify out of

the Gulf of Mexico and the Atlantic noted by 300K isentropic

upglide surging into the Carolinas with 6g/kg mixing ratios,

lifting into within the WCB into an impressive TROWAL by Sunday

morning, with PW anomalies rising to +1 to +2 standard deviations

above the climo mean. This should result in heavy precipitation

amounts, with rates becoming impressive especially within what

should be a strong pivoting deformation axis overlapping negative

theta-e lapse rates NW of the mid-level low. Additionally, upslope

flow into the terrain will likely drive additionally enhanced UVVs.

 

The concern for this event will be how much cold air can be

dynamically produced by the system itself, as the antecedent

airmass is modest for early February. This could result in a

situation where snowfall accumulates during periods of more

intense ascent (within the deformation, in the terrain due to

upslope) but changes back to rain when rates lighten. The guidance

is fairly well clustered overall, but there are clear camp

differences noted in DESI clusters with the ECENS a slow/strong

solution, the GEFS a faster weaker model, and the CMCE somewhere

in between. With such an impressive closed low, the slower

solution seems more reasonable, and while this would limit the

snowfall potential towards the Mid-Atlantic, it could enhance the

snowfall potential in the Appalachians from northern GA through

WV, with additional bursts of snow possible anywhere from MS

through central VA during periods of more intense lift.

 

The other challenge with this event will be the snow-liquid ratio

(SLR). Even during periods when precipitation changes to all snow,

the soundings suggest the near-surface layer will be right around

freezing with a similar near-0C isothermal layer above. The median

February SLR for this area is only 9:1 according to the Baxter

climatology, and this is maybe a ceiling for the SLR forecast for

this event. With rain and snow mixing at times, SLR will be highly

variable and probably quite low, which is also reflected by PWSSI

for moderate impacts being driven primarily by snow load. A lot of

variability results in a lower than usual confidence forecast, and

CIPS analogs suggest accumulations will be confined to the higher

terrain, which in this case would be above around 3000 ft

according to NBM snow levels. However, as noted above, dynamic

cooling under intense ascent could result in light accumulations

almost anywhere in the vicinity of the upper low. Still, the

greatest risk for any significant accumulations will be in the

terrain, and WPC probabilities for 4 or more inches of snow reach

50-80% across the NC mountains and into southwest VA where locally

8-10 inches of snow is possible. Probabilities for more than 2

inches extend northward almost to the MD Panhandle.

 

[Holston_River_Rambler]

That disco sounds pretty optimistic wrt the dynamics involved. 

[Silas Lang]

11 minutes ago, Holston_River_Rambler said:

I think its just "see where everything sets up" time. 

Yeah, that's looking like what we are going to have to do considering all the variables. Really think this could go any which way and everything is still on the table at the moment.