014 
FXUS64 KMRX 111820
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
220 PM EDT Tue Aug 11 2026

...New DISCUSSION...

.KEY MESSAGES...
Updated at 218 PM EDT Tue Aug 11 2026

- Showers and thunderstorms will be possible each day through the
  end of the work week, with the best chance of rain during each
  afternoon.

- There will be potential for a few storms to become strong to 
  severe each afternoon with damaging winds and localized flooding
  the main threats.

- Temperatures will be near normal through Friday, but trending 
  slightly above normal for the weekend.

&&

.DISCUSSION...
Issued at 218 PM EDT Tue Aug 11 2026

The regional radar mosaic shows multiple areas of convection 
upstream over the Ohio Valley and southern Great Lakes. The exact 
evolution of these structures is uncertain, but the likelihood of 
one of these structures to impact our area is high. There are a few 
isolated thunderstorms developing across the southwest VA ahead of 
the main MCS over N KY and W WV. These storms could produce isolated 
winds and heavy rainfall. If we see repeated rounds of storms and 
showers over any area, the potential for flooding and flash flooding 
will increase and may require flood headlines in the future. 
Forecast soundings across SW VA & NE TN highlight 2000-3000+ j/kg 
CAPE with ~20 knots of shear. This is plenty for clusters of 
thunderstorms to develop and produce isolated hail/wind damage. 
Forecast soundings further west in SE TN highlight significant 
instabilty available for thunderstorms to tap into. The general 
consensus is that we'll see the MCS or a portion of the MCS upstream 
follow the instability gradient that goes through our eastern 
forecast area of SW VA/NE TN. The instability in place will be 
plenty for MCS maintenance and the structure itself will likely be 
able to enhance the local shear environment to a more favorable 
situation. The timing appears to be between 4 to 8pm for our NE area 
with uncertainty on how far south/west it'll continue. Additional 
MCS over central Indiana should continue to move south-southeast and 
should arrive in our northern area this evening. The exact evolution 
of this is even more uncertain due to the unknowns with this 
afternoon's potential convection. There is reason to believe that 
the second round should maintain some intensity and bring another 
round of thunderstorms capable of producing damaging winds and heavy 
rain. This structure does have some mid level support as an impulse 
transits through the Ohio Valley this evening/tonight. This should 
move through the area this evening and into tonight before we begin 
to dry out. Given the general uncertainty and lower-than-normal 
confidence with this forecast, please monitor the forecast if you 
have any outdoor work or activities planned this afternoon - evening.

Wednesday through Friday... this period remains unsettled with the 
potential for additional showers and thunderstorms each afternoon. A 
strong ridge remains off to our west and a trough to our east over 
the NE CONUS. This places us in a favorable area for daily 
shower/thunderstorm chances through Friday evening. There will be a 
non-zero chance for a few of these storm to become strong to severe 
and able to produce heavy rainfall. There isn't a clear signal for 
any one area but rather a broad brush approach given the unstable 
airmass and northwest flow aloft. The finer details won't be 
resolved likely until the day of given the lower confidence tied to 
this pattern. 

Saturday through Early Next Week... The western ridge axis will 
build into the area this weekend. This will allow warmer 
temperatures to settle in through the start of next week. 
Precipitation chances will continue through the weekend, but the 
chance of any organized convection will be much lower. If the ridge 
builds in further east, we may even stay mostly dry Saturday/Sunday, 
which would welcomed. 

&&

.AVIATION...
(18Z TAFS)
Issued at 130 PM EDT Tue Aug 11 2026

Overall, VFR conditions are expected outside of any passing 
thunderstorm. Showers and storms are expected in some capacity 
through this afternoon and into the overnight hours. Confidence in
timing and coverage is low at the moment. Amendments may be 
needed prior to the 00Z TAF issuance. If we do see a strong line 
of convection move out of KY and down into TN, then TRI and 
perhaps TYS may see 40 to 50kt wind gusts as this line moves 
through. Again, low confidence as of now. 

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             73  93  74  94 /  40  30  20  20 
Knoxville McGhee Tyson Airport, TN  73  90  73  91 /  40  40  30  30 
Oak Ridge, TN                       72  90  72  91 /  40  30  30  30 
Tri Cities Airport, TN              68  86  69  87 /  60  40  50  40 

&&

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

$$

DISCUSSION...BH
AVIATION...99


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