744 
FXUS64 KMRX 141826
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
226 PM EDT Fri Aug 14 2026

...New DISCUSSION...

.KEY MESSAGES...
Updated at 219 PM EDT Fri Aug 14 2026

- Scattered showers and storms continue this afternoon into this 
  evening and again Saturday, with chances generally higher north 
  than south. The threat of severe weather is low overall, but 
  there is potential for localized flooding and isolated damaging 
  wind gusts especially across our northern and eastern counties. 

- Very hot for the weekend and likely into Monday, especially 
  south and central valley areas. Then it will remain on the hot 
  side through the week but likely a bit less oppressive.

- Drier mid week, then an increase in chances for showers and 
  storms by Thursday and Friday. 


&&

.DISCUSSION...
Issued at 219 PM EDT Fri Aug 14 2026

The atmosphere remains quite moist and unstable, with scattered 
convection again occurring around the area. Given the lack of 
shear, the primary threat from the storms continues to be gusty 
winds with some marginal severe potential from wet microbursts 
mainly over our northern and eastern areas as highlighted in the 
SPC marginal risk. The other main concern continues to be flooding
given the abundant moisture, slow movement of the thunderstorms, 
and very wet soils over much of the northeastern half of our area.
Any prolonged or repeated heavy rains may result in localized 
flash flooding this afternoon into this evening. 

The upper jet retreats further north and heights rise over our area 
Saturday as the upper ridge to our west expands over our region. Our 
southwestern counties may stay mainly dry Saturday as the cap is
likely to strengthen enough to hold closer to the core of the 
ridge, although this is still not certain. Further north and east 
there continues to be a chance for showers and storms with threats
of wind and flooding similar to today. Sunday currently looks to 
have less coverage of showers/storms, with the best chance in the 
mountains and our northeast counties. 

The other concern heading into the weekend will be the heat.  High 
temperatures in the mid 90s will be common across portions of the 
central and southern valley, and some spots will climb into the 
upper 90s. Heat index values will likely approach or exceed 105 in 
some locations especially across the southern valley. A heat 
advisory issued earlier today will remain in effect through Sunday 
for the southern valley and southern Plateau. The heat advisory may 
end up needing to be extended further north into the central valley 
by later shifts. Monday also looks quite hot but with more 
uncertainty, as short wave energy moving by to our north suppresses 
the ridge and pushes a weak summertime cold front toward our area 
increasing the chances for showers and storms. Given uncertainty on 
timing of precipitation and cloud cover that may impact temperatures 
that far out, will keep Monday out of the heat advisory for now. 

Further out, models generally show some drying for the mid week 
period, with the NBM showing a mostly dry day Wednesday before 
chances for showers and storms increases again Thursday and Friday. 
It will continue to be hot for the Tuesday through Friday time 
frame, but currently the heat looks likely to be less oppressive 
than during the weekend. 

&&

.AVIATION...
(18Z TAFS)
Issued at 1236 PM EDT Fri Aug 14 2026

Showers and thunderstorms will be scattered this afternoon and 
not possible to time well at any given site, but will carry 
prob30 thunder groups all sites this afternoon. Fog development 
chances will at least partially depend on if and when 
precipitation occurs at a terminal which is still unknown, so 
will keep the MVFR vsby in fog for a few hours at TRI for now. 
Otherwise, will have VFR conditions outside of any thunderstorms. 

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             76  97  76  98 /  10  10  10   0 
Knoxville McGhee Tyson Airport, TN  75  94  75  95 /  10  20  10   0 
Oak Ridge, TN                       74  94  74  95 /  10  30  10  10 
Tri Cities Airport, TN              71  89  71  90 /  20  50  10  10 

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...Heat Advisory until 8 PM EDT /7 PM CDT/ Sunday for Bledsoe-
     Bradley-Hamilton-Marion-McMinn-Meigs-Rhea-Sequatchie-West 
     Polk.

VA...NONE.
&&

$$

DISCUSSION...99
AVIATION...99


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