780
FXUS64 KMRX 132354
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
654 PM EST Sat Dec 13 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 627 PM EST Sat Dec 13 2025

- Light snow accumulations expected across the high terrain of
  East Tennessee and southwest Virginia overnight into Sunday
  morning.

- Bitter cold will surge into the area for Sunday through Monday
  morning. Please see the Cold Weather Advisories for additional
  details.

- Warming trend begins Tuesday with above normal temperatures by
  mid to late week. Conditions will be dry during this time.

&&

.DISCUSSION...
Issued at 1236 PM EST Sat Dec 13 2025

A broad upper level trough remains in place over much of the central
and eastern CONUS. Shortwave energy translating through the synoptic
feature tonight into Sunday will sharpen the troughing as a surface
front progresses through the region. Some light ra/sn will occur
during the overnight hours as this energy translates through the
central and southern Appalachians, however, the greatest
probabilities for light snow accumulation will be limited to
higher terrain of the East Tennessee mountains and southwest
Virginia. Overall, moisture in the DGZ is lacking and better
northwest flow does not initiate until the bulk of the moisture is
departing the region. Will cover this with an SPS for now, ending
it at midnight to allow for the next forecast desk to make any
additional considerations.

The main concerns will be well below normal temperatures advecting
into the region as winds veer NNWly and become gusty behind frontal
passage. Temperatures around 20 degrees below normal are largely
expected across the region Sunday into Sunday night. A Cold
Weather Advisory has been issued for the Cumberland Plateau,
southwest Virginia, and our East Tennessee mountain zones starting
around sunrise tomorrow morning. The gusty winds and well below
normal temperatures will result in wind chill values around zero,
to as low as 10 below zero in the highest terrain of the
mountains. By late Sunday afternoon, the remainder of the valley
locations are introduced to the Advisory as cold air continues to
filter into the region. Overnight lows in the low teens to single
digits will be widespread. Many valley locations will see wind
chills in the single digits to near zero.

Cold Weather Advisory products will come to an end shortly after
daybreak Monday, when a gradual warming trend is expected into the
mid-week as the anomalous troughing ejects northeast and H5 heights
slowly recover. For Wednesday night through Friday, the main storm
track will be across the northern third of the nation. The fast but
more zonal flow will quickly move a series of short-waves with
associated frontal boundaries moving across the region. Ensemble
cluster analysis shows differences in timing of systems but overall
increasing chances of precipitation are expected towards the latter
half of the week.

&&

.AVIATION...
(00Z TAFS)
Issued at 627 PM EST Sat Dec 13 2025

A mix of rain and snow, mainly near TRI and TYS, is expected as a
trough moves through overnight. MVFR CIGs are likely at all
terminals until mid morning. Winds will become more northwesterly
and gusty in the early morning hours as a boundary moves through.
Gusts will be a bit higher once the clouds thin out in the morning.
Showers will start out as rain around midnight before changing to
light snow late tonight. Little to no accumulation is expected at
TYS. TRI may get up to half an inch.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             26  32  17  41 /  20   0   0   0
Knoxville McGhee Tyson Airport, TN  24  30  13  39 /  40  10   0   0
Oak Ridge, TN                       21  27  12  37 /  30   0   0   0
Tri Cities Airport, TN              21  27   8  35 /  70  10   0   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Cold Weather Advisory from 5 PM Sunday to 10 AM EST Monday for
     Cherokee-Clay.

TN...Cold Weather Advisory from 5 PM Sunday to 10 AM EST Monday for
     Anderson-Bradley-East Polk-Grainger-Hamblen-Hamilton-
     Hancock-Hawkins-Jefferson-Knox-Loudon-McMinn-Meigs-North
     Sevier-Northwest Blount-Northwest Carter-Northwest Cocke-
     Northwest Greene-Northwest Monroe-Rhea-Roane-Sullivan-Union-
     Washington TN-West Polk.

     Cold Weather Advisory from 7 AM EST /6 AM CST/ Sunday to 10 AM
     EST /9 AM CST/ Monday for Bledsoe-Blount Smoky Mountains-
     Campbell-Claiborne-Cocke Smoky Mountains-Johnson-Marion-
     Morgan-Scott TN-Sequatchie-Sevier Smoky Mountains-Southeast
     Carter-Southeast Greene-Southeast Monroe-Unicoi.

VA...Cold Weather Advisory from 5 PM Sunday to 10 AM EST Monday for
     Scott VA.

     Cold Weather Advisory from 7 AM Sunday to 10 AM EST Monday for
     Lee-Russell-Washington VA-Wise.

&&

$$

DISCUSSION...99
AVIATION...99