983 
FXUS64 KMRX 271752
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
152 PM EDT Sun Sep 27 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 147 PM EDT Sun Sep 27 2026

- Cool and dry conditions continue on Monday, but a notable warm 
  up is expected Tuesday onward, with temperatures rising several 
  degrees above normal.

- The forecast for Friday into next weekend remains uncertain. 
  Does rain return by Friday, or hold off until late Saturday? 
  Details aren't clear at this time.


&&

.DISCUSSION...
Issued at 147 PM EDT Sun Sep 27 2026

Upper troughing will continue over the NE CONUS, with ridging from 
Texas NNE into the western Great Lakes region, through late Monday. 
This will keep dry conditions, with low afternoon RH and 
temperatures around or slightly below normal, in place across the 
forecast area. Speaking of low RH values, the NBM is once again too 
high with afternoon dewpoints, so a heavy handed dose of CONSShort 
and HRRR dewpoints were mixed in for this afternoon and Monday as 
well. By Tuesday the upper trough pulls away into the northern 
Atlantic, and the ridge shifts east towards the Appalachian, 
remaining there through the latter part of the week. Expect 
continued dry conditions, with a notable warm up Tuesday through 
Thursday, with afternoon temperatures rising several degrees above 
normal.

For the end of the week, there's mixed reviews on how the pattern 
evolves and how quickly rain chances return. The evolution of the 
pattern across the CONUS will be based on the interaction of an 
upper low that will move onshore in southern California and 
Hurricane Polo which is forecast to move NNE across the Baja 
peninsula, both of which occur on Monday. Previous model runs had 
those phasing into a closed upper over the desert southwest and more 
slowly shifting east across the southern CONUS through the week, 
with a weaker northern stream jet across southern Canada, yielding 
prolonged ridging over the southeast and a late Friday or maybe 
Saturday return of rain chances to our area. Trends in some guidance 
over the last 24 hours have been for a stronger Canadian jet, a 
quicker eastward movement of the upper low and subsequent weakening 
of the southeast ridge, and thus a quicker return of Gulf moisture 
and rain chances to the southern Appalachian. That's not universally 
the case though, as some guidance maintains a stronger ridge and 
slower progression of things, still putting rain off until late 
Saturday into Sunday. Suffice it to say, the forecast for Friday 
into next weekend is far from certain and there's plenty of time for 
significant shifts in the forecast. For right now, the forecast will 
reflect continued above normal temperatures for both Friday and 
Saturday (although closer to normal for Sat), with rain chances 
returning Friday afternoon and continuing into Saturday. I wouldn't 
be at all surprised if the slower timing is correct and the Friday 
rain forecast winds up being too pessimistic, but it's also not an 
unreasonable forecast for the moment either. 

&&

.AVIATION...
(18Z TAFS)
Issued at 147 PM EDT Sun Sep 27 2026

A persistence forecast was used for the 18z TAF package. No
notable changes in air mass or surface/upper level patterns are in
the forecast. As such, believe that VFR conditions should prevail
at KCHA and KTYS and that patchy fog will once again occur 
tonight and impact KTRI, with LIFR conditions expected. Any fog or
low clouds should dissipate by 13-14z, with a return to VFR
categories expected thereafter. Winds should be light, except for
some occasional gusts of 10-15KT at KTYS and KCHA through this
afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             54  84  55  86 /   0   0   0   0 
Knoxville McGhee Tyson Airport, TN  51  80  53  84 /   0   0   0   0 
Oak Ridge, TN                       50  80  53  83 /   0   0   0   0 
Tri Cities Airport, TN              47  76  52  80 /   0   0   0   0 

&&

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

$$

DISCUSSION...CD
AVIATION...CD


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