821
FXUS64 KMRX 291740
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
140 PM EDT Fri Aug 29 2025

...New DISCUSSION, AVIATION...

.DISCUSSION...
Issued at 133 PM EDT Fri Aug 29 2025

Key Messages:

1. Slight moderation in temperatures this weekend before another
cool down Monday into the rest of next week.

2. Mostly dry for valley locations through the weekend, with
isolated to scattered activity focused along higher terrain,
especially Sunday.

3. Scattered afternoon and evening precipitation chances return
Monday through much of the upcoming week.

Discussion:

Currently we are situated underneath northwest flow on the western
side of a trough axis extending from the eastern Great Lakes region
to the mid Atlantic Seaboard. A dry continental air mass and
surface high pressure will continue to promote mostly dry
conditions through Saturday as a stationary boundary remains
suppressed to the Gulf Coast. Isolated diurnal activity cannot be
ruled out across higher terrain of SW NC or the E TN mountains
Saturday afternoon, but valley locations will remain precip free.

As we head into Sunday, a reinforcing shortwave will swing through
the Ohio River Valley. Expect most valley locations to remain dry
once again, but coverage of convection will be more scattered across
the mountains and into SW VA(30-50% probabilities) owing to a vort
max and jet coupling aloft. NAMBufr soundings depict MLCAPE less
than 1000J/kg and PWAT values around 1.2", which is below the mean
value for this time of the year per SPC sounding data out of KBNA.
No sig weather is expected as a result. Though, if spending time in
vicinity of the higher terrain for the holiday weekend be prepared
for brief downpours and/or bouts of lightning to potentially
interrupt outdoor activities. Saturday and Sunday will also
experience temperatures a tad closer to seasonal norms.

For Labor Day, an additional shortwave will be progressing into the
Ozarks and broadening the troughing influence across the
southeastern United States. A return of cooler temperatures and
increasing chances of precipitation is expected areawide. This
pattern will persist through much of the work week, with
precipitation chances peaking during the afternoon and evening hours
each day. The exact timing and coverage of activity may be dependent
on how exactly shortwave impulses translate through mean flow aloft,
with potential for a greater coverage of activity in the Wed/Thu
timeframe associated with a more prominent shortwave and associated
frontal passage.

&&

.AVIATION...
(18Z TAFS)
Issued at 133 PM EDT Fri Aug 29 2025

Surface high pressure centered over the region will continue to
promote VFR conditions with light and variable winds throughout
the TAF cycle.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             61  88  62  85 /   0   0   0  10
Knoxville McGhee Tyson Airport, TN  60  85  61  84 /   0   0   0  10
Oak Ridge, TN                       59  85  60  84 /   0   0   0  10
Tri Cities Airport, TN              55  82  57  80 /   0   0   0  30

&&

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

$$

DISCUSSION...KRS
AVIATION...KRS