136
FXUS64 KMRX 161056
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
656 AM EDT Thu Oct 16 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 646 AM EDT Thu Oct 16 2025

- Dry and mild conditions will continue today with cooler
  overnight lows in northeasters areas. Patchy frost is possible.

- A system will affect the region this weekend, bringing potential
  of strong winds in the mountains Saturday night. Showers and
  storms are likely by Sunday, and the severe threat is dependent
  on how slow the front moves in during the afternoon.

- Drier and cooler conditions return by Monday, followed by a
warming trend and possible showers and storms mid-week.

&&

.DISCUSSION...
Issued at 138 AM EDT Thu Oct 16 2025

Currently early this morning, broad ridging is centered to our west
with surface high pressure over the upper Great Lakes, continuing
northeasterly flow and dry and mild conditions. Heading into
tonight, ridging will gradually shift eastward with surface high
pressure settling just northeast of our area. The combination of
increasing subsidence and weaker MSLP gradient/winds will allow for
temperatures to drop more than recent nights in the northeast. Some
places could reach the upper 30s with patchy fog definitely possible
for some. On Friday, the flow aloft will become more zonal with
surface high pressure weakening as it progresses east of our area.
This will continue the warm and dry conditions with a more southerly
shift in winds.

On Saturday, the pattern to our northwest will be the main focus as
troughing deepens and becomes negatively tilted with cyclogenesis
taking place across the Great Plains. Models still differ some on
timing and exact evolution, but the consensus is for a surface low
below 1,000mb to develop and progress to the Great Lakes by the
evening. Strong upper divergence due to upper divergence to the
north will strengthen 850mb flow to over 50 kts ahead of the cold
front. During the day on Saturday, the result in our area will be
unseasonably warm temperatures and increasing southerly winds.
Depending on the exact orientation of the 850mb jet and MSLP
gradient, a mountain wave event could transpire overnight. However,
there are still questions about these details. The next question
will be about the timing of the cold front on Sunday. The latest GFS
solution is actually slower than the NAM. A slower timing could
allow for better destabilization in our area ahead of convection in
the afternoon. Based on the overall pattern, strong directional and
speed shear would almost certainly be in place with increasing
instability supporting a notable severe risk. This risk would be
greatest in southern portions of the area where probabilities for
sufficient instability are highest. Essentially, the slower the
timing in the front, the higher the severe risk will be in our area.

Troughing and the associated cold front are expected to be east of
the area by Sunday evening, leading to cooler and drier conditions.
An area of high pressure will keep the region dry on Monday. By the
end of the period, there are indications of another trough/system
moving into the region. Some sources suggest this setup to also be
potentially dynamic and conducive for storms in the eastern U.S.
with a return of rain chances in our area at a minimum.

&&

.AVIATION...
(12Z TAFS)
Issued at 646 AM EDT Thu Oct 16 2025

There is little to no fog this morning. We do have a low cloud
deck at TRI around 4K feet. This should scatter out a couple hours
after sunrise. Dry and VFR conditions continue this TAF cycle.
Maybe some low gusts mainly near CHA with northeasterly winds.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             79  53  81  59 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  75  49  77  56 /   0   0   0   0
Oak Ridge, TN                       75  49  76  55 /   0   0   0   0
Tri Cities Airport, TN              70  40  72  50 /   0   0   0   0

&&

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

$$

DISCUSSION...BW
AVIATION...McD