977
FXUS64 KMRX 131742
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
142 PM EDT Thu Jun 13 2024

...New AVIATION...

.UPDATE...
Issued at 1120 AM EDT Thu Jun 13 2024

So far the weather is on track today for another warm June day.
Visible satellite shows scattered clouds, primarily along the
higher elevations of the area ridges and mountains, with another
cluster of clouds in the southern valley. Forecast is on track,
with only minimal edits to the sky cover and blended observations
in with the forecast to represent the rest of the day today. HREF
guidance shows best chance for a thunderstorm this afternoon along
the TN NC line of mountains, depending on if rising air parcels
can ascend through a warm air layer aloft.

&&

.SHORT TERM...
(Today and tonight)
Issued at 221 AM EDT Thu Jun 13 2024

Key Messages:

1. Low probability of showers/thunderstorm across the far east
Tennessee Mountains and southwest North Carolina this afternoon.

2. Increasingly hot conditions developing.

Discussion:

A weak shear axis will move slowly east of the southern
Appalachians this morning taking the high and mid-level clouds
with it. HREF shows widely scattered/scattered convection across
the far east Tennessee mountains and southwest North Carolina. Due
to continued relatively dry airmass, stable layer/inversion
between 850-700mb, and low MLCAPE values of 250-500 at best, plan
on limiting convection to low probability.

Temperatures will continue the trend of warmer highs/lows for
today and tonight.

For tonight, besides a few light showers in the mountains early,
dry conditions.

&&

.LONG TERM...
(Friday through Wednesday)
Issued at 221 AM EDT Thu Jun 13 2024

Key Messages:

1. Temperatures rising through the weekend, peaking on Sunday but
remaining above normal through the first half of next week.

2. Isolated to scattered showers and thunderstorms are possible
each afternoon, mainly over the higher terrain.

Discussion:

A cold front will be pushing into our area from the north at the
start of the forecast period. It will likely be a dry fropa, since
the midlevel flow remains NW-N ahead of the front. Friday will have
some slight chance PoPs in northern sections and the mountains. High
pressure over the Great Lakes will feed some lower dewpoints into
the area, but temperatures will remain above normal, with highs in
the upper 80s to mid 90s Friday and Saturday. The heat and humidity
ramp up on Sunday as the large mid/upper level high pressure ridge
over the southern Plains shifts east to MS/AL/GA, and the surface
high shifts off the Mid-Atlantic coast. With highs well into the 90s
across the TN Valley, and dewpoints in the upper 60s to lower 70s,
the heat index may exceed 100 in the central and southern Valley.

Organized convection is unlikely under the ridge, but there may be
enough low level moisture and afternoon instability to spark a few
showers and thunderstorms in the higher terrain areas through the
first half of next week. Monday appears to have the best chance as
we get a more southerly low level flow up the Valley and higher 850
mb theta-e values. Still, this is only a low chance to slight chance
as the 500 mb ridge remains directly over the southern Appalachians.
Previous model runs that had shown a Gulf moisture plume spreading
into the region in the Monday-Tuesday time frame have now shifted
that moisture farther west. So any precip chances next week will be
mainly diurnally-driven and favor the terrain areas. With the mainly
dry conditions, high temps will be bumped up a little over NBM for
Monday through Wednesday - highs in the 90s will continue.

&&

.AVIATION...
(18Z TAFS)
Issued at 132 PM EDT Thu Jun 13 2024

VFR and dry expected through the TAF period. Cumulus clouds this
afternoon with a very low chance of an isolated shower or TS along
elevated ridges and mountains. Overnight clear skies and calm
winds expected. Tomorrow similar daytime weather as today expected
under the ridge of high pressure.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             70  95  71  95 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  67  91  69  91 /   0  10   0  10
Oak Ridge, TN                       66  91  68  91 /   0  10   0   0
Tri Cities Airport, TN              63  88  65  87 /   0  20  10  10

&&

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

$$

SHORT TERM...Wellington
LONG TERM....DGS
AVIATION...Wellington