215
FXUS64 KMRX 192326
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
726 PM EDT Tue Aug 19 2025

...New AVIATION...

.DISCUSSION...
Issued at 133 PM EDT Tue Aug 19 2025

Key Messages:

1. Limited coverage of showers and storms is expected today, mainly
across the mountains of East Tennessee and southwest North Carolina.
Localized flooding is possible with slow movement.

2. Increased coverage of storms is expected Wednesday through Friday
with locally strong wind gusts and isolated flooding possible.

3. Some rain chances linger into the weekend, but notably cooler
temperatures are expected by early next week.

Discussion:

In the upper levels, there is a strong ridge centered over the
Rockies. Troughing is over the Eastern U.S. with a shortwave in the
Northeast and Hurricane Erin staying well off the East Coast. At
the surface, high pressure is centered near the Great Lakes and a
weak cold front will likely move through the region late Wednesday
as seen by a wind shift. This weak front is also seen on WPC
analysis, although only a very slight drop in dew points and
temps are expected. Showers and storms will be more scattered
Wednesday, Thursday and Friday with the best chances in the
afternoon during max heating. By Thursday and Friday the best
chances will be in the East Tennessee and North Carolina mountains
as the weak boundary stalls to the south and washes out. Once
again gusty winds and localized flooding will be possible with
decent CAPE around 1000 J/kg expected each afternoon. The risk for
isolated flooding will be primarily Thursday and Friday due to
slow storm motion with light steering flow expected.

Rain chances will increase by Saturday as a more significant trough
moves into the Upper Mississippi and Ohio River Valleys. The surface
low will be vertically stacked with the upper low well to the north
in Canada. At the surface, a real cold front will be moving through
late Sunday bringing a cool, dry air mass from Canada into the
Tennessee Valley. Monday and Tuesday will be dry with
significantly cooler temps (highs in the upper 70s and lower 80s) as
a trough sits over the Eastern U.S.

&&

.AVIATION...
(00Z TAFS)
Issued at 722 PM EDT Tue Aug 19 2025

Extended PROB30 for thunderstorm potential at CHA for another
couple of hours, but things should overall be on the downward trend
for the night. Calm expected overnight. A PROB30 for Wednesday afternoon
and evening added this issuance for a return possibility of
thunderstorms at all terminals.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             73  93  72  89 /  10  60  10  40
Knoxville McGhee Tyson Airport, TN  73  91  71  88 /  10  50  20  40
Oak Ridge, TN                       72  90  71  87 /  10  60  20  30
Tri Cities Airport, TN              68  88  68  85 /   0  50  30  50

&&

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

$$

DISCUSSION...McD
AVIATION...KS