Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
653
FXUS64 KMRX 250720
AFDMRX
Area Forecast Discussion
National Weather Service Morristown TN
220 AM EST Tue Nov 25 2025
...New DISCUSSION, AVIATION...
.KEY MESSAGES...
Updated at 157 AM EST Tue Nov 25 2025
- Gusty winds across the east TN mountains and foothills, with a
Wind Advisory in effect through this afternoon.
- Low probabilities for a few strong to severe storms this
afternoon and evening, mainly areas south of I-40.
- Drier and colder for Thanksgiving.
- Temperatures moderate by the weekend, with another potential rain
maker moving in by Sunday.
&&
.DISCUSSION...
Issued at 157 AM EST Tue Nov 25 2025
At the time of writing this discussion(130AM ET), an upper trough
is digging through the northern CONUS towards the Mid Mississippi
River Valley. An embedded shortwave and vort max in vicinity of
the Tennessee Valley will continue to promote development of a
strong H85 jet out of the SSW. Isentropic lift associated with
this LLJ combined with a warm front lifting through the region
will bring increasing coverage of showers through morning hours
into the early afternoon. Per latest soundings and SPC
mesoanalysis, instability should be very limited and elevated with
the AM activity. This will keep severe chances very limited in
the morning hours, but any heavier downpours could help transport
some strong flow aloft to the surface. A surface inversion should
help limit this threat as well, nonetheless, some stronger gusts
between 30-40mph cannot be ruled out. Additionally, this LLJ will
continue to promote a low-end mountain wave event in the East
Tennessee mountains and immediate foothills. Strongest gusts
between 45-55mph will be in elevations 3000ft or greater and the
standard mountain wave prone locations such as Camp Creek and Cove
Mountain. Cove mountain has already reported a peak gust of
42mph, while the LLJ is expected to peak in intensity between
12Z-17Z.
Additional showers and storms are expected to develop along and
ahead of a surface cold front this afternoon. This is likely
where the better chances at having isolated severe weather exists
due to the potential for surface based storms, however,
development of SBCAPE is not a guarantee and will depend how much
time we can get to destabilize, if any at all. The most likely
timeframe for this will be around 16Z-00Z. Given the strongly
sheared profile, isolated damaging wind gusts and a brief tornado
or two will be the primary concerns. This isolated severe threat
is largely confined to areas south of I-40, including the southern
Plateau, southern Valley, and southwest North Carolina. This is
expected to be a largely beneficial rainfall as storm motions will
be quick. Though, if a storm trains due to terrain influence or a
few heavier downpours repeat over one location in quick
succession, isolated flooding may occur in low-lying or poor
drainage locations.
A few light showers may linger through Wednesday morning as
northwest flow develops and tries to squeeze out any lingering
moisture, but mostly dry conditions are expected Wed through Sat.
The main impacts will be anomalously low H5 heights bringing
seasonally cool conditions around 10 degrees below normal for
Thanksgiving Day and Friday. Temperatures will slowly rebound
through the weekend, with lower confidence in rain chances making a
return by the latter half of the weekend into early next week.
&&
.AVIATION...
(06Z TAFS)
Issued at 157 AM EST Tue Nov 25 2025
A period of unsettled weather is expected this TAF cycle.
Showers will gradually become widespread this morning. A brief
lull in activity is expected around mid-day to early afternoon,
then additional scattered showers and a few thunderstorms will be
possible again throughout the afternoon and evening. CHA has the
greatest chances of experiencing MVFR cigs this morning/afternoon,
while downslope impacts hinder these chances at TYS/TRI. HREF
probabilities of MVFR or low cigs developing tonight are in the
30-60% range.
A period of LLWS is also expected due to a strengthening LLJ this
morning. Gradually take out the LLWS as rain chances and surface
winds increase mid to late morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 69 54 61 34 / 100 60 0 0
Knoxville McGhee Tyson Airport, TN 68 53 59 31 / 100 80 10 0
Oak Ridge, TN 66 51 59 31 / 100 70 10 0
Tri Cities Airport, TN 64 52 59 29 / 90 70 20 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...Wind Advisory until 4 PM EST this afternoon for Blount Smoky
Mountains-Cocke Smoky Mountains-Johnson-Sevier Smoky
Mountains-Southeast Carter-Southeast Greene-Southeast
Monroe-Unicoi.
VA...NONE.
&&
$$
DISCUSSION...99
AVIATION...99