-- Discussion containing changed information from previous version are highlighted. --
587
FXUS64 KMRX 091105 AAA
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
705 AM EDT Wed Jul 9 2025

...New AVIATION...

.SHORT TERM AND LONG TERM...
(Today through Next Tuesday)
Issued at 128 AM EDT Wed Jul 9 2025

Key Messages:

1. Strong to isolated severe storms are possible this afternoon
and evening. Primary threats will be damaging wind gusts with
torrential downpours that could lead to localized flash flooding.

2. Daily chances of afternoon showers and storms will continue
across the area into next week.

3. Near normal temperatures with muggy conditions are expected for
the remainder of the work week. A slight warming trend is expected
through the weekend into next week.

Discussion:

Similar to last night, mostly dry conditions are expected overnight
with some fog development particularly in and near river valley
locations. An upper trough shifting eastward into the Ohio Valley
this afternoon will enhance effective bulk shear to around 20kts,
allowing for increased coverage of afternoon convection relative to
previous days. Though weak, the shear will be efficient enough to
allow some updraft/downdraft separation and promote taller storms
alongside 2000-2500 J/kg MLCAPE. Precipitation loading could lead to
a few strong to isolated severe storms capable of producing
damaging wind gusts and flash flooding.

The band of enhanced mid-level flow will shift east of the area by
Thursday. Diurnal chances of showers and storms continue with the
trough axis on the eastern periphery of the forecast area. However,
slightly less favorable MLCAPE per latest NAM/HRRR model derived
soundings(1500-2000J/kg) and and EBWD less than 20kts suggest
limited potential for strong to severe activity - more so general
summertime convection. This pattern is expected to persist largely
through the entirety of the forecast period. Exact coverage or
potential for strong to severe storms will be partially dependent on
the timing and magnitude of any weak impulses traversing mean flow
aloft. Though, with continued days of afternoon convection and PWAT
between the 75th and 90th percentile based off SPC sounding
climatology from KBNA, isolated flooding concerns will be monitored
as we go through the week and into the weekend. For now, WPC
excessive rainfall outlooks highlight much of the area in marginal
risks through the first half of the weekend.

The end of the week will see a slight cooling trend due to more
persistent cloud cover and minor upper-level height falls. It will
still feel plenty muggy with dewpoints remaining in the low 70s.
Ambient temperatures will begin a slow upward trend during the
weekend and into early next week.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 701 AM EDT Wed Jul 9 2025

Incoming shortwave aloft should lead to SCT to NUM SHRA/TSRA this
afternoon. Still think there`s enough hit/miss coverage to warrant
only having PROB30s at all sites, but KTRI likely has the best
chances at seeing convection at the terminal later today.
Subsequently, KTRI is the most likely to see some fog or MVFR
CIGS tonight as well as a result of rainfall in that general
area. Guidance is hitting VSBY harder than low clouds so have
trended that direction. Elsewhere, any fog or low cloud potential
seems more limited.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Chattanooga Airport, TN             92  72  89  72 /  60  40  80  20
Knoxville McGhee Tyson Airport, TN  91  71  88  70 /  80  50  80  30
Oak Ridge, TN                       90  70  88  69 /  80  50  80  20
Tri Cities Airport, TN              88  68  84  67 /  90  70  80  40
-- End Changed Discussion --

&&

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

$$

SHORT TERM...KRS
LONG TERM....KRS
AVIATION...CD