904 
FXUS64 KMRX 281054
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
654 AM EDT Fri Aug 28 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 643 AM EDT Fri Aug 28 2026
 
- Isolated to scattered storms expected this afternoon. The
  greatest chance will be along the eastern mountains. 

- Most locations will be dry for the weekend with return of hot
  and humid conditions early next week.

&&

.DISCUSSION...
Issued at 229 AM EDT Fri Aug 28 2026

Regional radar mosaic reveals a few isolated storms still present, 
but coverage and intensity is on a downward trend. For the remainder 
of the night, we should see clearing skies a few lingering high 
clouds. There will likely be another round of patchy dense fog 
development as skies clear and winds turn light and variable. The 
worst of it is expected near area-waterways. Winds turn more 
northerly after daybreak with mostly sunny skies to start the day. 
Instability and moisture will be sufficient to support another day 
of isolated to scattered thunderstorm threat in the afternoon hours. 
Forecast soundings show 2000+ J/KG of MLCAPE and 7 C/km lapse rates 
that would support an isolated wind threat, but the threat of severe 
weather is low overall. Guidance suggests these storms will likely 
be tied to the mountains and terrain. Highs will be in the 80s and 
lower 90s with heat and humidity set to ramp up over the weekend.

Saturday's forecast will feature an inverted trough axis across the 
eastern half of TN. This should lead to diurnally driven storms 
along the eastern TN mountains and SW NC yet again. Most of us will 
remain dry. A pattern shift will be set in motion over the weekend. 
The upper level ridge over the SW CONUS will shift east across the 
centering over the SE CONUS by early next week. This places us in 
close proximity to the center of the ridge, ushering in mid-Summer 
like temperatures and humidity. Precipitation chances will be lower 
with the combination of rising heights and subsidence under the 
ridge axis. The NBM PoPs reflect this with suppressed values through 
mid-week. Sunday through the middle of next will will feature 
similar weather each day. Our high temperatures will warm into the 
low to mid 90s with overnight lows in the low to mid 70s. Surface 
dew points in the low to mid 70s will support heat indices in the 
100 to 105 range across the Valley. Afternoon storms cannot be ruled 
out with higher PWAT values in place. I suspect a scenario similar 
to early-mid August will play out with diurnal isolated storms that 
dissipate by sunset each day. Looking ahead, there really isn't a 
signal for a cooler-than-normal stretch as the synoptic pattern kind 
of cycles as the upper level ridges moves from the SW US to the SE 
US every ~10 days or so.

&&

.AVIATION...
(12Z TAFS)
Issued at 643 AM EDT Fri Aug 28 2026

Adjustments to visibility with the 12Z TAFs based on developing
low level clouds and light and variable wind that maintained
overnight. Ultimately left just TRI with VFR br for the next two
hours. Otherwise, a quiet weather day with northerly winds less
than 10kts. 

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             91  69  93  72 /  10   0  20   0 
Knoxville McGhee Tyson Airport, TN  89  67  91  69 /  10   0  10   0 
Oak Ridge, TN                       88  67  90  69 /  10   0   0   0 
Tri Cities Airport, TN              85  63  87  64 /  10   0  10   0 

&&

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

$$

DISCUSSION...BH
AVIATION...KRS


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