099
FXUS64 KMRX 091154
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
654 AM EST Sun Nov 9 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 638 AM EST Sun Nov 9 2025

- A strong cold front will move through the forecast area this
  morning, ushering in much colder temperatures to the area
  through Tuesday (as much as 20 degrees below normal by Monday).

- Behind the front, snow will be a concern for many areas through
  Tuesday morning. The Smokies are looking at a significant
  snowfall event, possibly exceeding 11" at Mount LeConte, while
  the remainder of the east TN mountains and higher terrain of our
  VA counties see lighter amounts in the 1 to 4 inch range.

- Generally speaking, valley accumulations should wind up around
  half an inch or less, and mostly occur Monday evening and
  Monday night. There could be some places that get an inch or so,
  but confidence in exactly where those accumulations occur is
  very low.

- Dry and more seasonal temperatures will return to the area mid
  to late week.

&&

.DISCUSSION...
Issued at 151 AM EST Sun Nov 9 2025

An impulse will move through the midwest and into the Ohio valley
through early this morning, driving a surface low along the same
path and pushing a cold front southeast through our forecast area by
the mid-morning time frame. This will allow for a strong cold air
advection regime to setup through late Tuesday and open a path for
an unseasonably deep, and very cold upper low to dive south from the
western Great Lakes through the southern Appalachian region between
this afternoon and Mon afternoon. Wintry precipitation is going to
be a concern in higher elevation areas and an initial Winter Storm
Warning and Winter Weather Advisory have been hoisted up to account
for this. It`s highly likely that some adjustments or outright
expansion of snowfall totals, areal coverage of these headlines, or
both, will be needed on the day shift today.

Getting into a bit more detail here, a northwest flow regime will
set up shop by this afternoon, with H85 temps falling below 0C and
precipitation switching over to snowfall in the higher terrain
around 00z this evening. Initial NW flow precip will be light, with
accumulating snowfall likely to be hit and miss due to saturation
into the DGZ not occurring until later tonight. However more
pronounced periods of QPF and subsequent snowfall are expected late
tonight through roughly daybreak Monday when stronger energy moves
through, and then again Monday afternoon and Monday night as the
core of the upper low moves overhead. Recent ensemble data shows
increasing confidence in a notable snowfall event for the Smokies,
with probabilistic data giving high confidence in snowfall totals
exceeding 8 inches. The evening shift updated the totals to include
an 11" total for Mount LeConte area, and Newfound Gap won`t be too
far behind that I don`t believe. Went ahead and upgraded the Watch
to a Winter Storm Warning because of this. Additionally, there`s
sufficient confidence in snowfall totals exceeding Advisory level
criteria elsewhere in the east TN mountains and the higher terrain
of our Virginia counties, so I added an Advisory to those areas,
grabbing Monroe county on the southern end too. There`s signal in
the higher resolution guidance that shows Sams Gap area along the I-
26 corridor closing in on the 5-6" range; I wouldn`t be surprised if
the High Knob area in Wise county winds up with something similar.
Elsewhere, other areas in the advisory should be covered just
fine with the 1-4" totals.

Lastly, snowfall totals in the lower elevations are going to be
tricky. As the core of the upper low rotates through the forecast
area Monday afternoon and evening, lapse rates aloft are going to be
quite high - in excess of 8C/km in some areas. This will coincide
with saturation, or near saturation, extending well beyond the DGZ.
As such, I am highly confident there will be widespread snow showers
across at least the northern half of the CWA, if not the northern
two thirds of the CWA during that time. It`s entirely possible some
locations could pick up an inch of snow or more - one might even say
it`s likely. However, confidence in where exactly that occurs is
very low.

&&

.AVIATION...
(12Z TAFS)
Issued at 638 AM EST Sun Nov 9 2025

Unexpected dense fog and low CIG developed overnight at TYS and
CHA. It won`t be long until pre-frontal winds arrive and
conditions should improve. SW-W winds and gusts will increase with
time today at all terminals. -SHRASN expected tonight and
overnight at TYS and TRI with varying CIG. -SHRA and possible MVFR
CIG at CHA tonight, but may remain at VFR the entire TAF period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             61  29  38  23 /   0  10  10  10
Knoxville McGhee Tyson Airport, TN  60  29  35  24 /  10  40  30  30
Oak Ridge, TN                       59  28  35  22 /  20  40  50  30
Tri Cities Airport, TN              60  29  34  22 /  20  50  50  50

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Dense Fog Advisory until 8 AM EST this morning for Cherokee-Clay.

TN...Dense Fog Advisory until 8 AM EST this morning for Bradley-East
     Polk-Hamilton-Knox-Loudon-McMinn-Meigs-North Sevier-
     Northwest Blount-Northwest Monroe-Rhea-Roane-West Polk.

     Winter Weather Advisory from 7 PM this evening to 7 AM EST
     Tuesday for Johnson-Southeast Carter-Southeast Greene-
     Southeast Monroe-Unicoi.

     Winter Storm Warning from 7 PM this evening to 7 AM EST Tuesday
     for Blount Smoky Mountains-Cocke Smoky Mountains-Sevier
     Smoky Mountains.

VA...Winter Weather Advisory from 7 PM this evening to 7 AM EST
     Tuesday for Russell-Washington VA-Wise.

&&

$$

DISCUSSION...KRS
AVIATION...KS