1-30/2-1-26 Arctic Blast, ULL Snow Event

[Tucker1027]

Could this be a repeat of 2014 from the south valley down into Atlanta?  

[Hurricaneguy]

After last week East TN summed up on these models right now 

[Carvers Gap]

19 minutes ago, bearman said:

I know it does not mean much, but it is nice seeing the broad Weather map from The weather prediction center showing at least parts of East TN in the heavy snow possibility/. Morristown must not be buying it, at least not yet..  

That map is a winner.  SLP over southern Louisiana and Mississippi.  A cold hp over the top.  That cold front dragging into the Gulf is often a spark as well.

[GBOVolz]

The last 4 GFS runs decreased the snow output specifically in Knox Co. The ratioed 8” line moved from I75 east to the Knox/Sevier/Jeff line. Only 10+ miles crow fly but it’s worth mentioning. Not sure if it’s an east jog or just a decrease in QPF. However the AIGFS actually increases the snow over Knox Co.


.

[Vol4Life]

1 minute ago, GBOVolz said:

The last 4 GFS runs decreased the snow output specifically in Knox Co. The ratioed 8” line moved from I75 east to the Knox/Sevier/Jeff line. Only 10+ miles crow fly but it’s worth mentioning. Not sure if it’s an east jog or just a decrease in QPF. However the AIGFS actually increases the snow over Knox Co.


.

I tend to trust the AIGFS a little more with precip totals….not just because it’s better for my backyard, but in its short time of existence, it appears to be a little more reliable.  

[Reb]

3 minutes ago, GBOVolz said:

The last 4 GFS runs decreased the snow output specifically in Knox Co. The ratioed 8” line moved from I75 east to the Knox/Sevier/Jeff line. Only 10+ miles crow fly but it’s worth mentioning. Not sure if it’s an east jog or just a decrease in QPF. However the AIGFS actually increases the snow over Knox Co.


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The RGEM did the best with this last storm IMO. Really hoping it scores a coup on this one as well.

[John1122]

The Euro Ai is less qpf than 06z. For some reason the last two days, 06z/18z runs are wetter, 12z/0z runs are more dry.

[Daniel Boone]

34 minutes ago, bearman said:

I know it does not mean much, but it is nice seeing the broad Weather map from The weather prediction center showing at least parts of East TN in the heavy snow possibility/. Morristown must not be buying it, at least not yet..  

They pop the LP exactly where we'd want and apparently project it to travel ENE , our preferred Route. 

[John1122]

For some reason the Euro isn't coming out. It's odd that the AI is out though. It's supposed to run off the Euro and just make tweaks to it.

[Vol4Life]

Good write up from NWS that came out about 15 min ago.  They are starting to buy in.  On phone…tried to copy, but I can’t get it to post here.

[tnweathernut]

13 minutes ago, John1122 said:

For some reason the Euro isn't coming out. It's odd that the AI is out though. It's supposed to run off the Euro and just make tweaks to it.

I have it out enough to see it's a plateau to east TN event.  Haven't seen the precip panels yet.  It whiffs middle TN completely.

[kvskelton]

2 minutes ago, Vol4Life said:

Good write up from NWS that came out about 15 min ago.  They are starting to buy in.  On phone…tried to copy, but I can’t get it to post here.

582
FXUS64 KMRX 281732
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
1232 PM EST Wed Jan 28 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 1229 PM EST Wed Jan 28 2026

- It will be dry but temperatures will remain below normal today
  through Thursday.

- Snow is increasingly likely Friday afternoon through Saturday,
  especially in the eastern and northeastern portions of the
  region.

- Arctic cold will return for the weekend.

.DISCUSSION...

We remain under broad eastern CONUS troughing aloft, with surface
high pressure currently over our region.   This set up will keep us
dry but with below normal temperatures through Thursday night.

By Friday, models are in general agreement that a strong short wave
will be diving southeast out of the Plains, cutting off by Saturday
as it tracks over our area and then lifting off to our northeast
Sunday. A weak surface low pressure system is forecast to develop
near the northern Gulf and then move east and offshore the SE coast
before strengthening rapidly as it tracks to the northeast off the
East Coast. This system will bring at least some light snow to the
area, and in this case precipitation type is not in question but the
uncertainty lies in how much snow will fall.  Right now it appears
we will have light snow begin to show up Friday especially north as
we see weak isentropic lift out ahead of the main system. Then, as
the upper low approaches and the upper jet to its south noses in, we
will see a period of upper divergence that will enhance snow
chances.  Of course, the exact track of the upper low and the
surface low to our SE and E will be critical, and the models often
struggle with these details even just a few days out. Right now, the
best chances for significant snow accumulations look to be over our
eastern and northern areas.  Currently, NBM probability data shows
around a 40% to 60% chance of 72 hour snowfall exceeding 4 inches
by Sunday morning across our northern and central mountains as
well as eastern portions of the NE TN valley and SW VA, and a 20%
to 50% chance of exceeding 2 inches of snow across much of the
central valley, northern Plateau, and western portions of NE TN.
Orographically enhanced snow showers may linger into Sunday across
the normally favored terrain as well.

The other story for the weekend will be the cold.  Another surge of
arctic air will rush in on north and northwest winds, and high
temperatures Saturday will struggle to get above the lower 20s even
in the valleys.  Low temperatures Saturday night will be in the
single digits in most areas.  Wind chill values will dip into the
single digits in the valleys with well below zero values at times in
the higher terrain as well Friday night through Saturday night.
Sunday will likely see temperatures remaining below freezing for
nearly all of the area, and Sunday night will to be very cold as
well.

Models are in general agreement that we will see height rises aloft
and gradually moderating temperatures Monday through Wendesday. There
is poor agreement on additional waves that may bring precipitation,
but there is at least a modicum of agreement for more precipitation
chances arriving by Wednesday.

&&

.AVIATION...
(18Z TAFS)
Issued at 1229 PM EST Wed Jan 28 2026

VFR conditions expected through the period, besides a brief TEMPO
for MVFR CIGs at TRI this afternoon. Winds will be gusty at TRI this
afternoon through early evening with gusts to around 24kts out of
the west. Otherwise, mostly quiet conditions through the next 24
hours.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             22  42  26  43 /   0   0   0  20
Knoxville McGhee Tyson Airport, TN  20  39  25  40 /   0   0   0  30
Oak Ridge, TN                       19  38  24  40 /   0   0   0  30
Tri Cities Airport, TN              14  34  21  37 /   0  10   0  50

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

$$

DISCUSSION...99
AVIATION...99

 

[John1122]

The Euro is probably not going to be very good for areas along and west of 75.  Hopefully it's wrong, but it's usually only wrong when it shows significant snow.

[Vol4Life]

3 minutes ago, John1122 said:

The Euro is probably not going to be very good for areas along and west of 75.  Hopefully it's wrong, but it's usually only wrong when it shows significant snow.

How different is it from 06z?  I feel like it hasn’t been firmly in the camp with GFS and CMC. It’s made steps towards those solutions, but is still barely on the outside looking in.

[Daniel Boone]

I think MRX is too high on Forecasted Temps Saturday and Sunday. They're adjusting to Climatology looks like as Guidance looks colder.

[John1122]

11 minutes ago, Vol4Life said:

How different is it from 06z?  I feel like it hasn’t been firmly in the camp with GFS and CMC. It’s made steps towards those solutions, but is still barely on the outside looking in.

It's further east with the Vort vs prior/better runs. The further east that vort, the further east the moisture.

[John1122]

Brutal for my area if the Euro is correct. QPF cut in half, even of it's own 12z AI and 25 percent of other models.  It's been fairly dry, but had been improving. 

[Tucker1027]

lol @Chattanooga 

[Vol4Life]

2 minutes ago, Tucker1027 said:

lol @Chattanooga 

You said earlier that you’d take an inch.  This is for greater than 2”.  The hope is still alive! lol!

[Tucker1027]

Just now, Vol4Life said:

You said earlier that you’d take an inch.  This is for greater than 2”.  The hope is still alive! lol!

Yeah I know, but thought the picture was funny and captures the struggle of Chattanooga in the winter. I'll still take an inch. 

[Wurbus]

5 minutes ago, Tucker1027 said:

lol @Chattanooga 

I think I'm right on that blue/red line in the middle of Knox county

[Vol4Life]

Something is going on with the Euro.  It is still stuck at 75h.  Wouldn’t be surprised if there’s some feedback issues.

[John1122]

I think areas near I-81/east currently have a 2-4 inch floor with a much higher ceiling and are almost locked in with a decent snow event.

West of 81 back to the Plateau, the 06z Weather Next, GFS, GFS AI, Canadian, RGEM, NAM, are generally 2-4+ inches.

Euro Ai is probably 2-3 inches at 12z.

The Euro is maybe 1-1.5 at best at 12z, but it was 2-4 at 06z.

[Bigbald]

11 minutes ago, Tucker1027 said:

lol @Chattanooga 

Pet peeve but I thought it pretty much universal thinking to go from lighter color to darker color for small to higher measures.  These maps always throw me for loop.

[Daniel Boone]

OZ tonight will be the most telling irt Trends imo.

[Vol4Life]

2 minutes ago, John1122 said:

I think areas near I-81/east currently have a 2-4 inch floor with a much higher ceiling and are almost locked in with a decent snow event.

West of 81 back to the Plateau, the 06z Weather Next, GFS, GFS AI, Canadian, RGEM, NAM, are generally 2-4+ inches.

Euro Ai is probably 2-3 inches at 12z.

The Euro is maybe 1-1.5 at best at 12z, but it was 2-4 at 06z.

Kuchera looks a little more promising.  3.4” at TYS

[John1122]

Hopefully the Euro ticks back west some with the ULL at 18z. It's been doing that on the 18z/06z runs.

[Vol4Life]

1 minute ago, John1122 said:

Hopefully the Euro ticks back west some with the ULL at 18z. It's been doing that on the 18z/06z runs.

Yes, it wouldn’t take much 50-100 miles makes a world of difference.

[GBOVolz]

Hopefully the Euro ticks back west some with the ULL at 18z. It's been doing that on the 18z/06z runs.

Isn’t the 0z and 12z initiated differently?


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[John1122]

Weather Next is similar to it's 06z run, it has around an inch of snow back to Nashville. Around 2 inches eastern rim/western Plateau, 3+ inches along 75 corridor to the Smokies, and 4+ in NE areas east of 81.