266
FXUS64 KMRX 030530
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
130 AM EDT Wed Sep 3 2025

...New DISCUSSION, AVIATION...

.DISCUSSION...
Issued at 121 AM EDT Wed Sep 3 2025

Key Messages:

1. Increasing chance of showers and thunderstorms Wednesday and
Thursday. Main concerns will be locally heavy rainfall and a
marginal threat of severe storms on Thursday.

2. There will be another chance for showers and storms Friday night
and Saturday, although chances remain mostly below 50 percent.

3. A cooldown is likely by Sunday after a cold front passage
late Saturday.

Discussion:

Shower activity may pick up late tonight. CAMs are split, some have
scattered coverage and some have nothing. Higher confidence in
showers and storms after daybreak today through the afternoon and
early evening as a deep trough sits over the Eastern U.S. A vort max
will move into the northern half of the region this afternoon aiding
in development. Several CAM members have scattered showers this
afternoon across the region. The HRRR has showers isolated and
mainly confined to SW Virginia and NE Tennessee closer to the better
lift. Instability will be pretty weak today with ML CAPE maxing out
around 700 J/KG.

By Thursday, a deep trough is still over the Eastern U.S. At the
surface, a weak cold front will stretch from Canada and into the
Tennessee and Ohio River Valleys. This does not look like a clean
frontal passage. This front will likely stall just north of our
region. Thursday afternoon will have a tad better instability with
ML CAPE around 600 to 1000 J/KG. There is a low end threat for a few
storms producing gusty winds during max heating Thursday.

Friday looks dry with increasing POPs Friday night and Saturday as a
cold front approaches. Generally POPs will remain below 50 percent.
This will be a clean frontal passage Saturday night or Sunday
morning bringing cooler temps and lower dew points. Also, a
noticeable wind shift to northerly winds.

&&

.AVIATION...
(06Z TAFS)
Issued at 121 AM EDT Wed Sep 3 2025

Confidence on fog development this morning is low. Better
confidence in the possibility of MVFR CIGs this morning. Scattered
rain showers will develop in the morning hours. Confidence is
lower before daybreak since guidance is split. Showers and
possibly a few storms will be likely in the afternoon hours mainly
near TRI. Showers will be more isolated near TYS and CHA, so
confidence is lower there.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             84  63  86  66 /  20  20  40  10
Knoxville McGhee Tyson Airport, TN  81  62  83  65 /  40  10  50  10
Oak Ridge, TN                       81  61  82  63 /  40  10  60  10
Tri Cities Airport, TN              75  57  79  60 /  70   0  60  20

&&

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

$$

DISCUSSION...
AVIATION...