792
FXUS64 KMRX 141705
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
105 PM EDT Mon Jul 14 2025

...New SHORT TERM, LONG TERM, AVIATION...

.SHORT TERM...
(This evening through Tuesday)
Issued at 103 PM EDT Mon Jul 14 2025

Key Messages:

1. Isolated to scattered showers and thunderstorms through this
evening. Locally gusty winds and heavy downpours possible with the
strongest storms.

2. Hot and humid conditions on Tuesday, with isolated showers and
storms. Central and southern TN valley will see Heat Indices in
upper 90s to low 100s. Heat Indices in the low to mid 90s more
likely for NE TN, SW VA, and SW NC.

Discussion:

We are currently in zonal flow due to high pressure to our south and
a weak upper trough to our north-northeast. This will allow for
another day of isolated to scattered showers and storms through this
evening. Storms will be of the summer-time pulse variety due to
little to no shear in the atmosphere. MLCAPE values should average
around 1500 J/kg through the afternoon. Any stronger storm could
lead to gusty winds up to 40mph as well as isolated flash flooding.
Patchy dense fog possible yet again tonight for areas that see
decent rainfall today.

On Tuesday, the trough is well to our northeast. This allows high
pressure to push further north. This should result in the more
traditional summer-time terrain driven showers and storms that occur
during the afternoon hours. This should result in less coverage
across valley locations compared to the last few days.

The bigger story will be the heat and Heat Indices. Heat indices in
the upper 90s to near 100 are expected for the central East
Tennessee valley, with the southern valley reaching near or into the
low 100s. Slightly lower Heat Indices in the low to mid 90s are
expected for northeast Tennessee, southwest Virginia, as well as
southwest North Carolina.

That being said, the exact timing of convective initiation and
coverage of storms could impact these values. Less storm coverage
and later initiation means higher probability that these forecast
Heat Indices occur. Earlier initiation and greater coverage means
these forecast values are much less likely.

&&

.LONG TERM...
(Tuesday night through next Monday)
Issued at 103 PM EDT Mon Jul 14 2025

Key Messages:


1. Daily chances of PM showers and storms continue through the
extended period. With each day, the strongest storms could produce
locally gusty winds and heavy downpours, with possible flash
flooding.

2. Upper ridge remains strong through the long term. Upper 90s to
low 100s Heat Indices will be common across the central and
southern TN valley.

Discussion:

Upper level ridging will likely remain strong through the period.
The only exception may be on Thursday, as a shortwave trough passes
to our north. High pressure may be strong enough to prevent this
feature from dipping to far south and into our area. Otherwise, the
hot and humid airmass will promote Heat Indices in the upper 90s to
low 100s across the central and southern TN valley. Lower Heat
Indices in the low to mid 90s are expected across north TN,
southwest VA an NC. Please practice heat safety during this time.

Diurnal summer-time showers and storms expected each day. The
greatest focus will be along the high terrain of the Cumberland
Plateau and mountains of east TN, southwest NC, and southwest VA. On
any given day, any stronger storm will be capable of producing
strong gusty winds and heavy rainfall which could lead to isolated
flash flooding.

&&

.AVIATION...
(18Z TAFS)
Issued at 103 PM EDT Mon Jul 14 2025

VFR conditions are expected to prevail for much of the next 24
hours across the three TAF sites. However, diurnal heating will
lead to the development of scattered thunderstorms this afternoon
and early evening, primarily between 19Z and 00Z. Any fog
development overnight should be localized and not significantly
impact flight operations with the exception of KTRI. Fog affecting
visibility late tonight will clear shortly after sunrise.
Otherwise conditions will return to VFR a little later Tuesday
morning.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             73  95  75  92 /  10  20  20  60
Knoxville McGhee Tyson Airport, TN  72  96  73  94 /  20  30  30  60
Oak Ridge, TN                       71  94  72  92 /  10  30  30  60
Tri Cities Airport, TN              68  89  70  88 /  30  50  40  70

&&

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

$$