-- Discussion containing changed information from previous version are highlighted. --
415
FXUS64 KMRX 160748
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
348 AM EDT Sun Jun 16 2024

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

.SHORT TERM...
-- Changed Discussion --
(Today and tonight)
Issued at 340 AM EDT Sun Jun 16 2024

Key Messages:

1. High pressure begins to shift east today with southerly return
flow. Continued hot weather.

2. Higher precipitation coverage expected this afternoon compared
to the past couple days--mainly across southern areas and higher
elevations.

Discussion:

The 592 dam 500mb upper ridge axis remains across the
Appalachians and the Carolinas this afternoon with surface high
pressure shifting eastward with weak southerly flow returning to
the region. This will result in continued above normal
temperaturesacross the region. Moisture will be highest across
southern counties, and precip chances will be maximized across
southern higher elevation areas near the Southern Zone Cherokee
National Forest and southern Cumberland Plateau. Thunderstorms
will be possible, but severe weather is unlikely.

Afternoon convection will decrease in coverage tonight with
clearing sky conditions. Patchy fog will be possible for areas
that receive rainfall this afternoon.
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&&

.LONG TERM...
-- Changed Discussion --
(Monday through Sunday)
Issued at 340 AM EDT Sun Jun 16 2024

Key Messages:

1. Isolated to scattered thunderstorms are expected on Monday with
hot and dry conditions through most of the week.

2. Low-end chances for storms return by next weekend with continued
hot temperatures well into the 90s.

Monday through Wednesday

At the start of the period, ridging will be in place with a 5,920m
500mb high centered just to our east. A strong surface high will be
centered just off the New England coast. This initial setup will
continue hot and humid conditions into Monday to start the period.
Around the 250mb level, a weak jet streak of near 40 kts will
approach from the southwest and help to provide at least some upper
divergence. With decent moisture remaining in place, diurnal
convection is anticipated again, especially along the higher
terrain. The environment will be modestly unstable (MLCAPE near
1,000 J/kg) with very weak shear. This will keep the severe
potential very limited with strong winds possible in any storms that
become tall enough.

By Tuesday, the 500mb high will strengthen further to our northeast,
reaching near 5,960m. The Atlantic surface high will expand westward
and will advect drier air into the area. This trend will diminish
chances for convection and will continue anomalously hot conditions.
With the advection of drier air, lower humidity will keep heat index
values close to the actual air temperature. By Wednesday, the 500mb
high will strengthen even more to a near record 6,000m over New
England with surface high pressure expanding even more into the
area. Similarly hot and dry conditions can be expected again.

Thursday through Saturday

Late in the week into the weekend, the overall pattern will remain
fairly similar to Wednesday, continuing hot conditions through the
end of the period. One feature to watch is the potential development
of a weak tropical cyclone east of Florida. Based on the latest
National Hurricane Center (NHC) forecast, this probability is near
30 percent. If it develops, the progression would be towards the WNW
into the southeastern U.S. However, the very strong high would
likely keep this system to our south. The result is a reintroduction
of low-end PoPs by the end of the period with no other impacts
currently anticipated.
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&&

.AVIATION...
(06Z TAFS)
Issued at 112 AM EDT Sun Jun 16 2024

High pressure will begin to shift east today with return moisture
arriving from the south. Increased moisture will result in
slightly higher instability with Prob30 groups for thunderstorms
at terminals during the afternoon hours. Otherwise, VFR conditions
will prevail with light winds.

&&

.PRELIMINARY POINT TEMPS/POPS...
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Chattanooga Airport, TN             95  74  93  74 /  30  10  20   0
Knoxville McGhee Tyson Airport, TN  93  72  91  71 /  40  10  30  10
Oak Ridge, TN                       93  71  92  70 /  40  20  30   0
Tri Cities Airport, TN              89  68  89  67 /  30  10  50   0
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&&

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

$$

SHORT TERM...JB
LONG TERM....BW
AVIATION...JB