893 
FXUS64 KMRX 130532
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
132 AM EDT Thu Aug 13 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 115 AM EDT Thu Aug 13 2026

- Periods of showers and storms continue today and Friday. There 
  is low confidence on timing and coverage, but each day there is 
  potential for localized flooding and strong to isolated damaging
  wind gusts. 

- A warming trend is expected Friday into the weekend. Saturday 
  through Monday look to be the most hot and humid days. Heat 
  Advisory products may eventually be needed. 

&&

.DISCUSSION...
Issued at 115 AM EDT Thu Aug 13 2026

Latest MCS is departing to our east with a few isolated showers and 
light stratiform rain briefly in its wake. Will let the Flood Watch 
run as planned due to lingering activity, but overall the threat of 
any additional flooding is largely trending downward.
Unfortunately, this predominant northwest flow continues to promote 
a low confidence forecast over the next 48 hrs, particularly in 
regards to timing and coverage of shower and storms. The overnight 
will be primarily quiet, but additional showers and storms are 
possible as we head into the late morning and per latest CAMs. We 
will remain in an environment with high PWs but due to little to no 
surface instability, thus, storms would likely be elevated and 
struggle to produce much in terms of a wind threat. Localized 
flooding cannot be ruled out. Allowing the Flood Watch to continue 
as planned will also allow us to see how radar trends play out into 
the morning, as CAMs are currently doing a very poor job with some 
spotty CI occurring over northern KY. 

An additional round of showers and storms is possible this evening, 
similar to tonight. Again, models are highly variable in coverage(or 
general presence) and timing of this activity. The warm and moist 
summer airmass could allow for MUCAPE near 2k J/kg and mid-level 
lapse rates 5.5-6.0 degC per latest HRRR soundings. The shortwave 
influence would also allow for effective shear near 20-25kts. A few 
strong or maybe isolated severe storms cannot be ruled out, 
primarily close to our northeast Tennessee into southwest Virginia 
counties. With repeated rounds of showers and storms over the past 
week, localized flooding could also occur with the strongest 
activity. Additional rounds showers and storms cannot be ruled out 
into Friday, but confidence further lessens as what happens with the 
preceding storms can impact evolution. 

However, we will start to see a warming trend Friday into the 
weekend as upper level heights see a gradual increase as a ridge 
axis shifts eastward. For the time being it looks like some isolated 
locations could approach Heat Advisory criteria Friday afternoon. As 
we head into the weekend, there will be an increasing chance for 
portions of the southern and central valley to see heat indices in 
the 100-107 degree range. A Heat Advisory may need to be considered 
as we get closer in time. Saturday through Monday look to be the 
most hot and humid days. While some precip chances linger into the 
weekend, they are primarily confined to the higher elevations like a 
more typical summer time day where a few isolated showers and storms 
could drift into the valley as the afternoon goes on. increasing 
coverage of PoP chances and slightly cooler temperatures are the 
theme Tuesday into mid-week as an amplifying trough in the Great 
Lakes region attempts to weaken the southeastern ridge.

&&

.AVIATION...
(06Z TAFS)
Issued at 115 AM EDT Thu Aug 13 2026

Guidance is in fairly good agreement in keeping most SHRA/TSRA 
activity limited to mainly the northern TN valley through the 
period. Thus, only have a PROB30 mentioned at KTRI and will keep 
convection out of the other terminals. There could be see some 
INVOF KTYS at some point this afternoon, but I'm just not 
confident enough to include it right now. Otherwise, flight 
categories should be largely VFR through the period, along with 
light winds outside of any convective influence. 

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             94  75  96  76 /  20  10  20   0 
Knoxville McGhee Tyson Airport, TN  91  75  93  75 /  40  20  30  10 
Oak Ridge, TN                       91  74  93  74 /  40  10  40  10 
Tri Cities Airport, TN              86  70  89  71 /  50  50  50  30 

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...Flood Watch until 8 AM EDT this morning for Anderson-Blount 
     Smoky Mountains-Campbell-Claiborne-Cocke Smoky Mountains-
     Grainger-Hamblen-Hancock-Hawkins-Jefferson-Johnson-Knox-
     Loudon-Morgan-North Sevier-Northwest Blount-Northwest 
     Carter-Northwest Cocke-Northwest Greene-Roane-Scott TN-
     Sevier Smoky Mountains-Southeast Carter-Southeast Greene-
     Sullivan-Unicoi-Union-Washington TN.

VA...Flood Watch until 8 AM EDT this morning for Lee-Russell-Scott VA-
     Washington VA-Wise.

&&

$$

DISCUSSION...KRS
AVIATION...CD


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