094 
FXUS64 KMRX 230523
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
123 AM EDT Thu Jul 23 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 110 AM EDT Thu Jul 23 2026

- Very heavy rainfall will be possible with a threat of flash 
flooding overnight into Thursday over our south and southeast 
counties.

- High resolution models continue to show a heavy rain axis from 
roughly Hamilton county eastward to Monroe and Polk counties in TN, 
and Cherokee and Clay counties in NC overnight into Thursday. That 
is the area of highest concern.

-Additional showers and storms at times for the Friday through the 
end of the forecast period, especially across the south Friday and 
Saturday. 

&&

.DISCUSSION...
Issued at 110 AM EDT Thu Jul 23 2026

The main concern for the forecast period remains the possibility of 
additional flooding issues overnight and during the day Thursday. As 
of 10 PM EDT on Wed July 22nd, a cold front was situated in the TN 
valley, stretching southwestward into northern AL and MS. This is 
going to interact with a northward surging boundary (possibly a 
strong sea breeze aided by southerly low level flow on the 
northeastern periphery of TS Bertha) in the coming hours, kicking 
off more robust shower and thunderstorms from northern AL east-
northeastward into the southern TN valley and our western NC 
counties. Similar to last night, CAM guidance has been insistent on 
a fairly narrow swath of higher rainfall amounts with good 
probabilities of seeing over 5" of rain. This seems very plausible 
given confluent WSW low level flow and the high likelihood of 
training convection. Some brief storms in McMinn, Monroe, and 
southwest Blount county over the last couple of hours have radar 
estimates in the 2-3" range already. The Flood Watch that was 
issued for the southern areas seems well warranted and I see no 
reason for changes. In terms of timing, it once again seems like 
an overnight through mid/late morning threat window.

By late morning the influence of TS Bertha will be weakening, with 
increasingly northerly surface flow across the CWA and falling upper 
heights as shortwave energy moves in. This should push the front and 
associated rainfall threat just south of our area by the mid 
afternoon hours Thursday. That said, I wouldn't be surprised to see 
some lingering heavy rain/flooding threat in our far southeast TN 
and western NC counties well into the afternoon hours before the 
front is more confidently to our south.

For Friday onward, the general trend will be a building ridge out 
west and a deepening eastern CONUS trough. Plenty of shortwave 
activity moving from the upper midwest towards the southern 
Appalachian region from Friday through next week will result in an 
active weather pattern and periodic chances for showers and 
thunderstorms in the forecast area. A notable shortwave is seen to 
move from the Ozarks eastward across TN/KY on Friday, which should 
result in scattered convection across the area Friday afternoon with 
fairly decent coverage in the mountains thanks to low level westerly 
flow. Otherwise, timing of any one of these shortwaves this weekend 
into next weekend is difficult at the moment. Suffice it to say that 
there should be several opportunities for showers over the next week.

Temperatures for Thursday into Saturday look to be a bit below 
normal, then the remainder of the period will likely see 
temperatures back closer to seasonal norms.

&&

.AVIATION...
(06Z TAFS)
Issued at 110 AM EDT Thu Jul 23 2026

Highly variable conditions are expected overnight as on/off
showers affect CHA and TYS, with a range of VFR to IFR conditions
at times. TAFs will try to follow general trends without too many
TEMPOs/PROBs. CHA will have periods of showers all day as a front
stalls near the area. TYS will mainly have showers in the morning
hours, with improving conditions in the afternoon. Rain and MVFR
conditions at TRI at the moment should improve to VFR in the early
afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             84  72  86  72 /  80  30  80  50 
Knoxville McGhee Tyson Airport, TN  84  69  85  71 /  50  20  50  50 
Oak Ridge, TN                       84  67  85  70 /  20  10  40  50 
Tri Cities Airport, TN              82  65  82  67 /  20  20  60  50 

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Flood Watch through this evening for Cherokee-Clay.

TN...Flood Watch through this evening for Bledsoe-Bradley-East Polk-
     Hamilton-Marion-McMinn-Meigs-Northwest Monroe-Rhea-
     Sequatchie-Southeast Monroe-West Polk.

     Flood Watch through this afternoon for Blount Smoky Mountains-
     Cocke Smoky Mountains-Loudon-North Sevier-Northwest Blount-
     Sevier Smoky Mountains.

VA...NONE.
&&

$$

DISCUSSION...CD
AVIATION...DGS


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