508
FXUS64 KMRX 170646
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
246 AM EDT Mon Aug 17 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...
Updated at 238 AM EDT Mon Aug 17 2026

- Showers and storms will move through the area again today, some
  may be strong to severe with damaging winds the primary threat.

- Drier and not quite as hot mid week, then chances for showers
  and storms increase again Thursday into the weekend.

&&

.DISCUSSION...
Issued at 238 AM EDT Mon Aug 17 2026

Currently overnight convection has moved through northeast Tennessee
and southwest Virginia, but the overall synoptic pattern remains
fairly stagnant for Monday with another hot day expected.

A front will try and move into the region on Monday being aided by a
short wave in the mid levels of the atmosphere. Forecast soundings
continue to show an atmosphere that may be capable of organized
convection on Monday with plenty of instability to see rapid storm
growth with the expected hot temperatures. With a decent dry layer
in the mid levels helping to lead to DCAPEs eclipsing the 1,000 J/kg
mark the primary threat looks to be microbursts from these rapidly
growing thunderstorms. PWAT values climb back up to near the 2" mark
which means these storms will be capable of producing heavy
downpours. Cannot completely rule out a brief isolated tornado with
some weak low level shear, but it really looks like straight line
winds and flash flooding is the primary weather threats Monday
afternoon and evening.

The Heat Advisory will remain in place for Monday. It`s possible
that with mid level mixing due to the hot temperatures we bring down
lower dew point values like what occurred on Sunday, but it`s still
going to be near triple digit ambient temperatures, so will continue
with the Advisory.

We`ll cool down a bit on Tuesday (but it will still be hot for much
of the work week) with more notably cooler temperatures holding off
until the weekend. It won`t feel like fall, but we`ll see much more
widespread 80`s instead of 90`s late this week and into the weekend.
By Thursday into the weekend, heights fall over the region as the
upper level eastern US trough deepens. Chances for showers and
storms will increase again.

&&

.AVIATION...
(06Z TAFS)
Issued at 238 AM EDT Mon Aug 17 2026

A drier night at the surface at this time with only a few sites
showing 100% humidity. TRI may actually remain VFR through the
morning. SW-Wly winds will develop later today with near 10KT
possible at TYS and TRI. PRO30 for showers and storms introduced
as early as 19Z at the terminals to depict the chance between
those 6 hours due to a weak cold front. There`s uncertainty as to
storm severity and coverage because of drier air currently in
place.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             99  75  94  69 /  50  30   0   0
Knoxville McGhee Tyson Airport, TN  95  73  90  67 /  60  50   0   0
Oak Ridge, TN                       95  72  90  67 /  60  30  10   0
Tri Cities Airport, TN              90  69  85  64 /  80  70  20   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...Heat Advisory until 8 PM EDT /7 PM CDT/ this evening for
     Anderson-Bledsoe-Bradley-Hamilton-Knox-Loudon-Marion-McMinn-
     Meigs-Morgan-North Sevier-Northwest Blount-Northwest Monroe-
     Rhea-Roane-Sequatchie-West Polk.

VA...NONE.
&&

$$

DISCUSSION...
AVIATION...KS