299 
FXUS64 KMRX 230556
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
156 AM EDT Wed Sep 23 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 138 AM EDT Wed Sep 23 2026

- Scattered to numerous thunderstorms today, with lighter rain showers
  on Thursday. A low chance for flash flooding exists with any 
  prolonged heavy rainfall today.

- Comfortable early fall weather with no rain chances beginning
  Friday and persisting through the weekend.

&&

.DISCUSSION...
Issued at 138 AM EDT Wed Sep 23 2026

Here in southern Appalachia, we're getting another bout of homegrown 
showers and thunderstorms today. A diving trough cutting to the 
southeast underneath a Rex block will combine a good vort max, some 
mild upper divergence, and warm and moist air to produce another 
round of scattered to numerous thunderstorms later today. Effective 
shear is present underneath all that, around 20 knots, deep layer 
shear a little stronger, so depending on the storms it's possible 
there's one or two severe storms for wind gusts, though I'm not as 
sold on a severe hail risk. Otherwise storm motions are forecast to 
be near 10 knots, so slow moving storms do present a risk for flash 
flooding, especially if on previously saturated soils or vulnerable 
soils. Both 00z REFS and 00z HREF depict heavy rain swaths enough to 
induce flash flooding in the mountain counties south of Knoxville 
for today, but I wouldn't take the exact locations as gospel. 
Thursday skinny and somewhat shallow vertical profiles will still 
support a few showers, with perhaps more scattered light rain under 
the still moist atmosphere.

Chattanooga. Congratulations. After 50 days of 90F or hotter 
weather, you have attained the next part of the year: still warm but 
not excruciatingly hot. Possibly even more shocking are the low 
temperatures, after 100+ days of minimums being 60F or greater, 
Chattanooga will hit the 50s beginning this weekend. 

GFS/Euro are in agreement that we'll be on the backside of a solid 
nor'easter on the Eastern seaboard this weekend, which means we'll 
be on the receiving end of dry continental air while that storm 
system matures off the New England coast. Might have a few 
overperforming radiation nights this weekend in Virginia, skies look 
to be clear in the low PWAT environment with very dry air present. 
It is conceivable that a few colder hollows might get into, gasp, 
the upper 30s Saturday and Sunday mornings! First taste of fall has 
arrived. Daytime afternoon RH values are likely to lead to a very 
pleasant weekend, which is the best benefit from dry air plus still 
mildly warm temperatures.

&&

.AVIATION...
(06Z TAFS)
Issued at 138 AM EDT Wed Sep 23 2026

MVFR to IFR cigs will continue to expand into region overnight.
The combination of low cigs and some light wind should be enough
to prevent much dense fog from forming. MVFR cigs look to stick
around through early afternoon before they scatter out. Another
round of showers and storms will develop in the afternoon and
evening hours. Maintained the PROB30s given the uncertainty with
coverage. 

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             85  65  81  61 /  80  70  30  10 
Knoxville McGhee Tyson Airport, TN  81  64  76  58 /  90  90  60  10 
Oak Ridge, TN                       80  63  76  57 /  90  70  60   0 
Tri Cities Airport, TN              76  57  71  50 /  70  80  10   0 

&&

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

$$

DISCUSSION...Wellington
AVIATION...BH


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