743
FXUS64 KMRX 031729
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
1229 PM EST Wed Dec 3 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 1227 PM EST Wed Dec 3 2025

- Dry weather today and Thursday before increasing precipitation
chances late Thursday into Friday.

- Moderate chances for light snowfall across extreme northeast TN
  and southwest Virginia early Friday morning. Low probability
  light freezing rain/wintry mix central TN valley.
  Minor impacts possible.

- Very low probability of rainfall this weekend.

&&

.UPDATE...
Issued at 823 AM EST Wed Dec 3 2025

Cloud cover is expected to linger into the early afternoon hours
as lingering moisture remains trapped below an inversion. There is
some hope for clearing mid to late afternoon, starting in the
south then moving northward. Unfortunately, due to the persistent
cloud cover I had to lower afternoon temps by a few degrees.

&&

.DISCUSSION...
Issued at 1230 AM EST Wed Dec 3 2025

Low-level moisture still locked in across the region. Though the
moisture is shallow, NAM soundings show moisture up to around
-8 to -10 degrees Celsius. This aligns with the reports from earlier
this evening of a few light flurries/snow showers across our
northern areas. Because moisture is lingering, made an increase to
sky cover through the rest of the night and late morning. The NBM
wanted to clear things out way too fast. Sunny skies by this
afternoon. Then, dry weather through Thursday with below normal
temperatures.

As we have been discussing, we are still watching an incoming system
on Thursday night into Friday. We still aren`t in range of the Hi-
Res models, but the rest of the model data suggests moderate
probabilities of some light snow up across extreme northeast TN and
into portions of southwest VA, as well as portions of the east TN
mountains. LREF probs from DESI show between a 40 to 60% probability
of seeing at least 0.5 inches of snow across these areas. The higher-
end probs (60s) are along the TN/NC border up in northeast TN and
into the eastern portions of Washington County, VA. Whereas
locations between Rogersville and Tri-Cities are more in the 30 to
40% prob range. Upping the snow amounts to 1" drops the
probabilities to around 40% for extreme northeast TN and eastern
Washington County, VA. LREF Probs for trace amounts of freezing
rain or light wintery mix across the central TN valley is around
30%. Areas south of Knoxville should be all rain. The opportunity
for any snow accumulation across northeastern areas will be short-
lived though. Increasing southerly flow will bring about warming
temperatures, transitioning any frozen precip over to rain by late
morning/early afternoon.

Low confidence forecast through the rest of the period. Some models
show a dry Saturday, while the latest NAM and ECMWF keep light
showers in place. Latest NBM keeps slight chance POPs in through
Saturday. Slight chance/chance Pops then remain in place through the
rest of the period due to an active pattern across the U.S. This
makes it difficult to pinpoint exactly when and where any one system
will be moving through the the flow. Thus, this is why the NBM is
hanging onto Pops beyond the weekend.

&&

.AVIATION...
(18Z TAFS)
Issued at 1227 PM EST Wed Dec 3 2025

Satellite shows that the MVFR cloud deck is starting to break up
especially near CHA. The cloud deck looks thickest near TYS, so it
could be a few more hours before VFR conditions return there.
Most of the low CIGs will be scattered out by late afternoon.
Otherwise, VFR conditions are expected with mid clouds moving into
the region tomorrow morning.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             31  49  37  46 /   0  10  70  70
Knoxville McGhee Tyson Airport, TN  29  45  33  44 /   0  10  60  70
Oak Ridge, TN                       28  45  32  43 /   0   0  60  70
Tri Cities Airport, TN              26  43  29  42 /   0   0  40  70

&&

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

$$

DISCUSSION...99
AVIATION...McD