360
FXUS64 KMRX 011754
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
154 PM EDT Mon Sep 1 2025

...New DISCUSSION, AVIATION...

.DISCUSSION...
Issued at 132 PM EDT Mon Sep 1 2025

Key Messages:

1. Shower activity through Tuesday will be scattered to isolated,
and located mainly west of I-75.

2. Shower and thunderstorm chances increase ahead of a cold front
Wednesday and Thursday.

3. Drier weather over the weekend but not much of a temperature
drop until possibly early next week.

Discussion:

Showers today along the Cumberland Plateau have been associated
with an inverted surface trough from northern MS to eastern KY.
Over the next 24 hours, this trough is expected to drift westward,
so Middle TN will be the main area for showers to persist
overnight and redevelop tomorrow. CAMS are in good agreement that
any showers that make it into the evening will dissipate by
midnight. A few CAMS redevelop showers in our area tomorrow
morning, but the HRRR depiction of showers in Middle TN moving
east into our western sections in the afternoon looks more
reasonable, given the stable forecast soundings in the TN Valley
shown by the NAM. Chance PoPs tomorrow will be west of I-75, with
just slight chance PoPs in the Valley and TN/NC mountains.

A broad upper trough remains over the area through much of the
week, and an embedded shortwave trough makes its way toward our
area on Wednesday. Moisture depth increases with PW values in the
1.2 to 1.5 inch range across the area, but instability remains
weak. Some better instability develops on Thursday as a trough
drops into the MS Valley and a deep SW flow opens up the Gulf. PW
values rise near 1.8 in southern sections. A cold front will push
near the area by Thursday evening, but the model consensus is that
it will stall just north of our area on Friday. So we probably
will not see much of a cool-down late in the week as previous
forecasts had indicated. This may be delayed until another trough
rounds the broad trough on Sunday.


&&

.AVIATION...
(18Z TAFS)
Issued at 132 PM EDT Mon Sep 1 2025

VFR conditions and light winds are expected through this forecast
period. There are some showers near the Cumberland Plateau this
afternoon, but these should stay far enough away from TYS that
there should be no direct impact at the terminal.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             62  82  63  81 /  10  20  40  50
Knoxville McGhee Tyson Airport, TN  61  80  61  79 /  10  20  30  50
Oak Ridge, TN                       60  79  61  78 /  10  20  40  60
Tri Cities Airport, TN              53  77  56  76 /   0  10  20  60

&&

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

$$

DISCUSSION...DGS
AVIATION...DGS