152 
FXUS64 KMRX 121056
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
656 AM EDT Wed Aug 12 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 650 AM EDT Wed Aug 12 2026

- Periods of showers and thunderstorms will be possible each day
  through the end of the work week. Localized flooding and strong
  wind gusts will be possible with storms at times. 

- Temperatures will be near normal Wednesday and Thursday, with a
  gradual warming trend and into the weekend. 

&&

.DISCUSSION...
Issued at 243 AM EDT Wed Aug 12 2026

The MCS bringing us this past evenings activity has passed over 
the TN/GA border with light stratiform rain persisting across
portions of the forecast area in its wake. Overall, the threat 
for organized strong to severe storms and new flash flooding has 
diminished for the overnight, however, be cautious for any 
lingering flood issues as we continue into these early morning 
hours.

Additional periods of showers and storms are expected today through 
Friday as we remain in a predominant northwest flow pattern beneath 
the transition zone of a strong ridge axis to our west and a trough 
axis to our north and east. Comparing latest radar trends to the 00Z 
HREF Suite, NAM3km seems to be initializing the best with some 
additional CI and an associated vort lobe across eastern Indiana. 

The CAMs that do seem to depict this activity to a varying extent 
suggest some additional scattered showers and thunderstorms move 
through the area by about 12Z this morning. Quite honestly, I have 
little confidence in how this convection may play out. That being 
said, we have some very low 1hr FFGs between 0.9 to 1.3 inches due
to the evolution of this past evenings precip. Morning 
instability should be fairly limited, so the strong to severe 
threat is low but perhaps not zero depending how the intensity of 
the disturbance evolves. The main threat may be focused on the 
potential for some additional flash flooding, particularly for 
those very worked over locations in our central and northern 
areas. Have introduced a short fuse Flash Flood Watch due to the 
poor antecedent conditions. 

CAMs then generally want to dry us out for much of the mid-afternoon,
with an additional round of showers and storms possible in the 
late evening to early overnight. Cannot rule out some additional 
flooding concerns or even the potential for isolated strong to 
severe storms depending on how well we destabilize in the 
afternoon. Did not feel confident enough in how this second round 
of activity could develop to cover that with the Flash Flood 
Watch, but depending on how things evolve it isn't out of the 
realm of possibility an extension is needed. 

Again, additional periods of showers and storms are possible 
Thursday and Friday. The shortwaves look to be relatively weaker so 
the potential for strong/svr storms seems relatively lower, though 
not zero. We will also start to see an increase in upper-level 
heights by Friday and this will translate to a slight warming 
trend. Central and southern areas may be looking at Heat Advisory 
criteria as we head into this late week/weekend period. While we 
cannot totally rule out some diurnal pops, additional organized 
convection is unlikely. This pattern is expected to continue into 
next week extent but perhaps with temperatures a few degrees
cooler comparative to the weekend.

&&

.AVIATION...
(12Z TAFS)
Issued at 650 AM EDT Wed Aug 12 2026

Confidence in timing of convection for the 12z TAF period is not
very high. That said, it appears we should have two rounds of
convection today. One this morning, and then another after 04z 
tonight. Ongoing convection in SE KY should be INVOF KTRI by 13z 
and it's close enough to confidently go with a TEMPO group there. 
Further south, there's uncertainty in how well this will hold 
together, so just have PROB30 groups for this initial round at 
KTYS and KCHA. For the evening round, confidence is a bit lower 
still so just PROB30 for that round at KTRI and KTYS. Arrival 
time is late enough to preclude mention of it at KCHA. In terms of
flight categories, morning IFR CIGS will lift as showers move in.
Expect Mostly VFR after that, with occasional MVFR conditions in
convection.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             93  74  95  75 /  40  20  30   0 
Knoxville McGhee Tyson Airport, TN  91  73  92  76 /  50  50  40  10 
Oak Ridge, TN                       91  72  92  74 /  50  40  40  10 
Tri Cities Airport, TN              87  69  88  71 /  50  40  40  20 

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...Flood Watch until 3 PM EDT this afternoon for Anderson-Blount 
     Smoky Mountains-Campbell-Claiborne-Cocke Smoky Mountains-
     Grainger-Hamblen-Hancock-Hawkins-Jefferson-Johnson-Knox-
     North Sevier-Northwest Blount-Northwest Carter-Northwest 
     Cocke-Northwest Greene-Scott TN-Sevier Smoky Mountains-
     Southeast Carter-Southeast Greene-Sullivan-Unicoi-Union-
     Washington TN.

VA...Flood Watch until 3 PM EDT this afternoon for Lee-Russell-Scott 
     VA-Washington VA-Wise.

&&

$$

DISCUSSION...KRS
AVIATION...CD


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