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FXUS64 KMRX 081502 AAA
AFDMRX

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
1102 AM EDT Mon Jul 8 2024

...New UPDATE...

.UPDATE...
Issued at 1053 AM EDT Mon Jul 8 2024

The main change in the air mass over East TN in the past 24 hours
is an increase in dewpoints, from mid/upper 60s to lower/mid 70s.
Forecast soundings show better instability across the area, and
less of a capping inversion than yesterday. We are already
starting to see developing CU in visible satellite imagery. The
expectation is that showers and thunderstorms will develop as
heating increases, with the best potential across the higher
terrain areas in the Plateau and along the TN/NC border. This
activity may drift into the Valley, or produce outflow boundaries
that initiate new cells.

Not much needs to be changed to the forecast. Will adjust the
PoP/Wx grids to reflect the above thinking, with chance PoPs in
the terrain areas and slight chance PoPs in the Valley.
High temperatures will be raised a degree or two based on the
latest NBM and a comparison with yesterday`s highs. The greater
moisture content may result in highs a degree or two lower than
yesterday, but with highs expected to be in the mid to upper 90s,
the heat index this afternoon will likely be in the 100 to 105
range for the central and southern Valley.

&&

.SHORT TERM...
(Today and tonight)
Issued at 145 AM EDT Mon Jul 8 2024

Key Messages:

1. Isolated to scattered showers and storms areawide this
afternoon and early evening.

2. Heat Index in the 100-105 range in the southern Valley this
afternoon.

Discussion:

In the upper levels, a trough remains over the Great Plains and
Midwest. A weak ridge is over the Southeast and a closed low is
off the coast of the Carolinas. At the surface, a weak pressure
pattern is in place with a stationary boundary still lingering
just south and east of the region in Northern Georgia and Western
North/South Carolina. Most of the region will have 20 to 40
percent rain chances today with higher chances closer to the
boundary near the East Tennessee Mountains and Southwest North
Carolina. Most of the CAMs have showers and storms more isolated
in the Tennessee Valley.

Highs will be in the lower to mid 90s this afternoon in the
Tennessee Valley. With dew points creeping up into the 70s again,
heat indices will be 100 to 105 in the Southern Valley. A Heat
Advisory will likely not be issued today since most areas will
stay below the 105 threshold.

Remnants of tropical system Beryl, will start to move into
Arkansas tonight but our rain chances will remain low overnight.
Patchy fog will be possible in the early morning hours but may be
contingent on rainfall.

&&

.LONG TERM...
(Tuesday through Sunday)
Issued at 145 AM EDT Mon Jul 8 2024

Key Messages:

1. Heat indices of 100-105 degrees Tuesday as low-level moisture
increases over the Tennessee Valley region.

2. Afternoon convection likely for several days this week, and
remnants of Beryl will bring the best chances of rain to the region.
But likely  not enough to bust the drought.

Discussion:

Tuesday will likely be the hottest day of the week with temperatures
expected to be very similar to Monday, but dew point values should
be a few degrees higher leading to more muggy conditions and higher
Heat Index Values. A Heat Advisory may be needed for places along
and south of Interstate 40 as the Heat Index will likely cross over
the triple digit mark. But regardless or not if a Heat Advisory is
technically needed it will be HOT regardless across the entire
area...and heat safety should be practiced in the hottest and
sunniest parts of the day.

Moving into Wednesday we`ll get a very slight cool down and some of
our better chances of rainfall as the remnants of Beryl looks to
move through the Western Tennessee Valley, and will hopefully bring
enhanced moisture and more widespread showers and thunderstorms in
the afternoon/evening Tuesday and Wednesday. Fairly high confidence
we will see storm development on Tuesday and Wednesday, but lower
confidence on where the storms are and how much rain people see from
them.

Slightly cooler temperatures will remain in place through at least
Thursday with most places hopefully staying below the 90 degree mark
on Thursday. Moving into Friday we`ll see ridging building in as we
move through the weekend and a gradual warming trend into next week
with once again near triple digit Heat Index values to start off
next week with.

&&

.AVIATION...
(12Z TAFS)
Issued at 710 AM EDT Mon Jul 8 2024

There is some high cloud moving in from the west today but will
probably stay scattered most of the period. Showers and storms
will likely be isolated this afternoon in the Tennessee Valley,
therefore went with PROB30 group to show low end chances of storms.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             95  76  96  77 /  30  20  60  40
Knoxville McGhee Tyson Airport, TN  94  74  95  76 /  30  30  60  40
Oak Ridge, TN                       94  74  95  74 /  30  20  50  40
Tri Cities Airport, TN              92  71  94  72 /  30  20  50  20

&&

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

$$

SHORT TERM...DGS
AVIATION...McD