452 
FXUS64 KMRX 220605
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
205 AM EDT Tue Sep 22 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 159 AM EDT Tue Sep 22 2026

- Scattered showers and thunderstorms will be possible tonight through
  Wednesday. A few strong to severe storms capable of damaging 
  winds aren't out of the question, but overall severe chances are
  low. Additionally, some localized flooding could also occur, 
  but again chances are relatively low.

- Tuesday will be the last day with well above normal
  temperatures. Wednesday will feature near-normal temperatures 
  as a pattern shift occurs, with below normal temperatures 
  expected Thursday onward.

&&

.DISCUSSION...
Issued at 159 AM EDT Tue Sep 22 2026

Over the next 48 hours a rex block pattern will take shape over the 
eastern CONUS, with an upper low deepening over the Ohio valley and 
central Appalachian region and the upper high to its north 
strengthening over the Canadian side of the Great Lakes region. 
Meanwhile, surface high pressure develops beneath the ridge over the 
Great Lakes which will help to push a weak front, which was situated 
from West Virginia southwest into the Cumberland Plateau this 
evening, southward through the area sometime late Tuesday afternoon 
and evening. All of this will result in continued scattered to 
numerous shower and thunderstorm activity across the region through 
late Wednesday evening, with the best coverage during diurnally 
favored daytime hours but also with lingering convection during the 
overnight hours. For Tuesday, with the boundary slowly shifting 
south, the threat of any strong to severe storms should largely be 
relegated to the far southern TN valley and our western NC counties. 
However, PWATs will remain elevated through Wednesday, and storm 
motions very slow, so an isolated flooding threat could exist 
virtually anywhere through that period, though in general the 
risk of flooding should shift south with time as well.

Speaking of Wednesday, the pattern change really gets underway late 
Wednesday. The upper low associated with the rex block pattern, 
dives east southeast to the coastal Carolina region Wednesday night 
into Thursday, allowing for persistent northerly flow to spread 
across the CWA, ushering in significantly cooler and drier air. 
We'll still be warm on Wednesday, with highs in the mid to upper 80s 
south of I-40. But Thursday through the weekend will see highs 
topping out largely in the 70s, except the far southern TN valley 
which may still manage to best the 80 degree mark each day. Perhaps 
the more important note will be overnight lows in the 40s and 50s 
Friday night onward.

&&

.AVIATION...
(06Z TAFS)
Issued at 159 AM EDT Tue Sep 22 2026

Scattered thunderstorms will impact TYS and TRI for the first few
hours of the TAF. CHA should remain VFR as storms remain north of
the terminal overnight. After showers and storms exit, there could
be a short window of fog at TRI just prior to sunrise, but any
clearing in sky cover may support sub-MVFR vsby. Additional
thunderstorms develop this afternoon and will be scattered in
coverage. Additional TAFs will refine the timing for each
terminal. Showers and storms linger until Tuesday evening before
dissipating. VFR conditions return for the last few hours of the
TAF.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             91  68  86  65 /  70  30  60  40 
Knoxville McGhee Tyson Airport, TN  87  67  82  64 /  70  50  80  80 
Oak Ridge, TN                       86  66  82  63 /  70  40  70  50 
Tri Cities Airport, TN              82  63  77  58 /  80  70  80  60 

&&

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

$$

DISCUSSION...CD
AVIATION...BH


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