418
FXUS64 KMRX 071127
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
627 AM EST Sun Dec 7 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 621 AM EST Sun Dec 7 2025

- Cloudy conditions persist through the morning, with some sunshine
  breaking in through in the afternoon for some areas.

- Next system arrives Sunday night into Monday with very light
  precipitation. Some snow could occur in mountains and SW VA, but
  accumulations and impacts should be negligible.

&&

.DISCUSSION...
Issued at 1247 AM EST Sun Dec 7 2025

Fog has developed in parts of the area, and lowered visibilities are
expected to expand over the next few hours in southern sections.
Northern sections are likely to have more cloud cover based on
satellite trends, and should have less fog. With forecast lows in
the lower 30s to upper 20s, this could be freezing fog that could
cause some slick spots on bridges and overpasses. Through the day,
high and midlevel clouds will be increasing ahead of the approaching
shortwave trough that will bring rain in the evening.

Forcing for this precipitation will be driven mainly by a midlevel
shortwave trough, but no strong surface level forcing is depicted by
the models. Therefore, any precip should be fairly light over the
area. Measurable precip begins the area between 00Z and midnight as
the column moistens from the top down. By early Monday morning, cold
air advection ramps up and temperatures drop behind the low level
trough and a weak surface cold front, allowing for a transition to
snow for northern parts of our area. This will be mainly in
southwest VA and the eastern TN mountains, but outside the highest
elevations, any snow accumulations will be light and not likely to
be impactful. For the higher elevations of northeast TN, the NW flow
behind this shortwave that persists through Monday could result in a
inch or two accumulation through Monday evening, mainly along the
peaks of the mountains near the NC border. Amounts should stay under
Advisory criteria for populated areas.

Generally zonal flow throughout the atmosphere is expected through
the middle of the week, with temperatures warming a little (into the
50s for Wednesday) before our next system moves in towards the end
of the week. Temperatures appear to be fairly warm on the front end
with a big cooldown behind the low and front expected to move
through Thursday into Friday. We should see much colder temperatures
behind the front for the upcoming weekend, possibly dropping into
the teens for the weekend mornings with highs in the 20s and 30s.

&&

.AVIATION...
(12Z TAFS)
Issued at 621 AM EST Sun Dec 7 2025

Dense freezing fog has developed at all 3 sites with aviation
conditions to LIFR or less. This is expected to persist for the
next couple of hours with improvements to IFR then MVFR ceilings
by later this morning. Currently, TRI is expected to improve back
to VFR the fastest with CHA and TYS possibly not recovering until
early afternoon. Then later this evening, MVFR ceilings will
likely move back into the area from the south and west as chances
for rain increase with CHA and TYS forecast to drop again. Winds
will be light and variable at all sites through the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             52  41  48  29 /  10  40  10   0
Knoxville McGhee Tyson Airport, TN  50  39  43  28 /  10  40  30   0
Oak Ridge, TN                       50  38  44  26 /  10  40  20   0
Tri Cities Airport, TN              50  35  38  26 /  10  50  60  10

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Freezing Fog Advisory until 10 AM EST this morning for Cherokee-
     Clay.

TN...Freezing Fog Advisory until 10 AM EST /9 AM CST/ this morning
     for Anderson-Bledsoe-Blount Smoky Mountains-Bradley-
     Campbell-Claiborne-East Polk-Grainger-Hamblen-Hamilton-
     Hancock-Hawkins-Jefferson-Knox-Loudon-Marion-McMinn-Meigs-
     North Sevier-Northwest Blount-Northwest Monroe-Rhea-Roane-
     Sequatchie-Sevier Smoky Mountains-Southeast Monroe-Sullivan-
     Union-West Polk.

VA...NONE.
&&

$$

DISCUSSION...DGS
AVIATION...BW