Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN

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037
FXUS64 KMRX 111751
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
1251 PM EST Thu Dec 11 2025

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 1235 PM EST Thu Dec 11 2025

- Light snow accumulations across the north tonight into Friday,
  with impacts most likely across southwest Virginia.

- Bitter cold will surge into the area for Sunday into Monday.

&&

.DISCUSSION...
Issued at 1235 PM EST Thu Dec 11 2025

Tonight into early Friday will bring another round of light snow
for our far northern areas, especially in SW VA. A weak low
pressure system will be diving southeast toward our area out of
the Northern Plains, and while it will not have a lot of moisture
to work with, a band of isentropic lift and frontogentic forcing
north of its associated warm front will bring a band of light
precipitation for several hours tonight into early Friday. Thermal
profiles suggest this will be mainly snow. The most challenging
part of the forecast is exactly where the band will be and for how
long, which of course leads to uncertainties about snow amounts.
Right now, it appears the main impacts will be along our northern
fringe in SW VA. The latest HREF, REFS and NBM probabilities of
exceeding an inch across much of SW VA are in the 50-80% range,
but generally show low chances of 2 inches of more. This looks
reasonable, so will go with amounts of up to 2 inches. Will issue
a winter weather advisory for our SW VA counties, with the highest
confidence of impacts being across the northern part of the
advisory area.

Models are in good agreement that a strong cold front will push
through our area Saturday night followed by an area of cold high
pressure with its origins in Alaska and Western Canada. This system
will also have little moisture to work with, and current ensemble
data suggests little precipitation. However, a period of snow
showers and flurries can be expected Saturday night into Sunday
especially north and mountains as the much colder air surges in. It
will be quite cold for Sunday into Monday behind the front. Highs
Sunday will likely be around or below freezing in valley locations,
and Monday morning lows are currently forecast to be in the single
digits and teens across our entire area. It currently appears winds
will be on the decline once we get later in the night Sunday into
Monday which would suppress what could be worse wind chills, but
wind chill values in the single digits will be common in the valleys
with below zero values for the higher mountains at times Sunday
night into Monday morning.

High pressure will eventually shift eastward but will keep us dry
Monday through at least Tuesday. and Tuesday will be a little
warmer. Models are in poor agreement on when the next chance for
precipitation will arrive. Current ensemble data supports a gradual
warm up continuing for Wednesday and Thursday, with chances for
precipitation returning to the forecast by Thursday.


&&

.AVIATION...
(18Z TAFS)
Issued at 1235 PM EST Thu Dec 11 2025

Predominant VFR conditions for the 18Z TAF cycle. Increasing mid
level BKN/OVC clouds are expected tonight. For TRI, HREF
probabilities of MVFR cigs range from 40-70% between 4Z to 10Z
when occasional snow showers may also bring reduced visibility.
Clouds will gradually lift at TYS/CHA tomorrow afternoon, lingering
longest at TRI. W to WSW winds will increase between 8kts and
15kts tomorrow afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             33  59  34  58 /   0  10   0  10
Knoxville McGhee Tyson Airport, TN  32  54  33  54 /  20  10   0   0
Oak Ridge, TN                       31  54  31  52 /  30  10   0   0
Tri Cities Airport, TN              27  46  30  48 /  50  40   0   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...Winter Weather Advisory from 10 PM this evening to 10 AM EST
     Friday for Lee-Russell-Scott VA-Washington VA-Wise.

&&

$$

DISCUSSION...99
AVIATION...KRS