014
FXUS64 KMRX 180534 AAC
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
134 AM EDT Fri Sep 18 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 129 AM EDT Fri Sep 18 2026

- Well above normal temperatures to persist through early next
  week. Cooling towards normal by end of the forecast period mid
  to late week.

- Increasing rain chances for the higher terrain this weekend into
  early next week with the valley least likely to see rain,
  similar to a typical summer pattern.

&&

.DISCUSSION...
Issued at 129 AM EDT Fri Sep 18 2026

The anomalous ridge axis is located near or just west of the
Mississippi this morning. It will become centered over Ark-La-Tex
before further weakening and suppression as we get later into the
weekend. What this means for our area is we will return to a
diurnally induced precipitation pattern under weak northwesterly
flow. There will be a chance of isolated to scattered showers and
storms during the afternoon and early evening hours the entirety of
the forecast period. Like usual, chances will be best over the
higher terrain of the Southern Appalachians, Cumberland Plateau and
Mountains. No severe weather expected; the only hazards will be
lightning, possible heavy rain, and wind gusts. As we approach the
middle of the week next week, the upper level pattern may bring
shortwave troughing close to the region possibly providing more
widespread precipitation.

Temperature-wise, today appears will be the final "hottest" area-
wide with mid to upper 90s from the central valley down to the GA
border. Heat indices could reach the lower 100s range. Tomorrow,
temperatures and heat indices will be a smidge less for some, mostly
northeastern Tennessee into southwest Virginia. A touch less in
temperatures and heat indices Sunday and Monday, however, the more
notable drop possibly comes Tuesday. An approaching frontal system
and slightly lower heights aloft will be the big reason for what
might be noticeable relief early next week. Then, the relief further
infiltrates with lower temperatures and dew points Wednesday and
Thursday. Some valley locations may see upper 70s to lower 80s for
highs, which would be more in line climatologically for the end of
September. Until then, Chattanooga will continue to build onto their
record streak of 90 degrees or higher, now sitting at 45 days. Also
cannot go without mentioning that even though most of the area won`t
reach Heat Advisory criteria the next couple of days, that doesn`t
mean to let your guard down when it comes to being outdoors, staying
cool, and hydrated.

&&

.AVIATION...
(06Z TAFS)
Issued at 129 AM EDT Fri Sep 18 2026

All sites are VFR to start with mostly clear skies in place. Primary
concern this TAF period will be the onset of fog at TRI in the
early morning hours. I maintained the TEMPO group for 1/2 SM given
the trends upstream. Isolated to scattered showers and storms
develop near TRI this afternoon and early evening hours. Latest
hi-res guidance supports maintaining the PROB30. Winds light and
variable overnight and northerly around 5 knots after sunrise.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             98  74  98  71 /  10   0  40  20
Knoxville McGhee Tyson Airport, TN  95  71  94  70 /  20  20  30  30
Oak Ridge, TN                       95  71  93  69 /  20  10  30  30
Tri Cities Airport, TN              89  67  88  65 /  50  20  40  30

&&

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

$$

DISCUSSION...KS
AVIATION...BPH