919
FXUS64 KMRX 010632
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
232 AM EDT Tue Sep 1 2026

...New DISCUSSION...

.KEY MESSAGES...
Updated at 226 AM EDT Tue Sep 1 2026

- Hot and humid conditions will worsen with highs well into the
  90s and heat indices reaching or exceeding 100F for most
  Wednesday through Friday. Take frequent breaks and drink plenty
  of water when outdoors this week!

- Other than isolated storms in the mountains the next few days,
  rain chances do not return area wide until the weekend.

&&

.DISCUSSION...
Issued at 226 AM EDT Tue Sep 1 2026

If today is the start of meteorological fall, Mother Nature was not
given the memo. An oppressive 500 mb ridge will be parked over much
of the Mid South through this week, reaching above the 90th
percentile and flirting with the maximum values for this time of
year. As a consequence, high temperatures down here at the surface
are increasing as we head into the middle of the week, with highs
in the mid to upper 90s commonplace for much of the Tennessee
Valley and northern Plateau. Wednesday and Thursday carry a 45%
chance of hitting 100F at Chattanooga, and Thursday the NBM has a
50% chance in Knoxville of doing the same. Heat indices will climb
as well, with maximum values around 105F in the middle of the
week. Forecast temperatures alone will flirt with a couple of
daily records, namely on the 2nd and 3rd of September.

Daily Record High Maximum Temperatures

Date    Chattanooga    Knoxville      Tri-Cities     Oak Ridge
09-01   100(1957)      100(1951)      98(1953)       101(1953)
09-02   100(2011)      98(2011)       96(1943)       99(1953)
09-03   100(1954)      98(2011)       96(2011)       99(2011)
09-04   102(1954)      101(1954)      99(1954)       100(1954)

The upper ridge will get shunted to the west as we go into the
weekend. The degree of heat relief will depend on how significant of
an east coast trough we see, the GFS seems to have a more outlier
significant solution versus the Euro/EC-AIFS. Any weakening should
yield some relief outright, and maybe help initiate more storms to
provide quicker diurnal relief.

Rain chances are slim for much of this week. The overall oppressive
ridge won`t lend much to vertical CAPE profiles this week, and we
should see even less convection today as a result of the
increasingly hotter airmass. The degree to which we see more
widespread low chances of showers/thunderstorms over the weekend
into next week will depend on the depth of the upper trough and how
far west the upper ridge is pushed. For now much of the area has a
low rain chance returning each afternoon beginning on Saturday, when
even the Euro has a weak northwest flow shortwave to help spark
better coverage. Until then, the most significant weather hazard is
the anomalously high temperatures, with fairly regular humidity
pushing the combined heat indices to near or at heat advisory
thresholds for a couple days this week.

&&

.AVIATION...
(06Z TAFS)
Issued at 140 AM EDT Tue Sep 1 2026

Main concern for TAFs will be the potential for brief reductions
in visibility at TRI early this morning. Have included a tempo
with MVFR conditions. Otherwise, predominant VFR conditions with
light and variable winds are expected for the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             98  75 100  75 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  95  72  98  74 /   0   0   0   0
Oak Ridge, TN                       95  73  97  74 /   0   0   0   0
Tri Cities Airport, TN              91  69  95  69 /   0   0   0   0

&&

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

$$

DISCUSSION...Wellington
AVIATION...KRS