-- Discussion containing changed information from previous version are highlighted. --
900
FXUS64 KMRX 190712
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
312 AM EDT Sun May 19 2024

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

.SHORT TERM...
-- Changed Discussion --
(Today and tonight)
Issued at 310 AM EDT Sun May 19 2024

Key Messages:

1. Most locations will be dry today, but a few showers and storms
will be possible mainly across the E TN mountains and SW NC.

2. Dry and mild tonight.

Discussion:

We start the period with the upper trough axis just to our east and
ridging to our west. We will see rising heights over the region as
the upper ridge builds in and the trough continues to pull away.
Much of the area will be dry today, but a few showers and possibly
isolated thunderstorms are expected to linger mainly over the E TN
mountains and southwest NC. High temperatures today will generally
be a bit above seasonal normals.

Tonight will be dry with low temperatures again just few degrees
above seasonal normals.
-- End Changed Discussion --

&&

.LONG TERM...
-- Changed Discussion --
(Monday through Saturday)
Issued at 310 AM EDT Sun May 19 2024

Key Messages:

1. Drier and warmer Monday through Wednesday, only isolated
thunderstorm potential.

2. Higher chances (60 to 70%) for rain and thunderstorms Thursday
and Friday.

Discussion:

The start of the period on Monday begins with broad upper level
ridging anchored over the area. Available CAPE around 1000 J each
afternoon may support an isolated shower or thunderstorm, especially
over the terrain. As the week progresses, the low level ridging
moves off to our southeast, and better southwesterly flow brings a
steady stream of warm, moist air into the region. Far to our
northwest a broad upper level trough with embedded shortwaves
pivoting around will be dominating the north-central US. With
relative stationary movement amongst the larger synoptic scale
features into midweek, Wednesday has continued to trend drier,
though an afternoon shower or thunderstorm is still possible with
the summer airmass in place. GFS soundings for Wednesday afternoon
indicate a higher LCL base with a minor inversion just above that,
those factors will serve to limit storm formation.

By Thursday, an attempt at a weak frontal boundary will be
approaching the Ohio River valley, bringing higher chances for rain
and thunderstorms. The parent low will be north of the Great Lakes
by this time, making more significant convective weather difficult.
Temperatures on the back half of the week will cool slightly, though
likely not from the approaching front, just from more prevalent
showers and thunderstorms acting to dampen daytime solar heating. As
we get to Friday, guidance has been persistent in showing a
shortwave traversing across the center of the country, leading to
additional widespread showers and thunderstorms Friday afternoon,
depending on exact track. As that shortwave then exits, ridging will
return bringing lower storm chances tied back to a diurnal rhythm.
-- End Changed Discussion --

&&

.AVIATION...
(06Z TAFS)
Issued at 1252 AM EDT Sun May 19 2024

Main aviation weather concern will be any fog/low cig development
early in the period. Right now the best chance looks to be at
TRI, and will forecast conditions there down to MVFR/IFR for a
few hours. Will also include a tempo group with MVFR conditions at
TYS late tonight. Otherwise, VFR conditions are expected for the
period all sites.

&&

.PRELIMINARY POINT TEMPS/POPS...
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Chattanooga Airport, TN             85  63  86  64 /  10   0  10   0
Knoxville McGhee Tyson Airport, TN  82  60  83  63 /  10   0  10   0
Oak Ridge, TN                       83  61  85  62 /  10   0  10   0
Tri Cities Airport, TN              80  56  82  58 /  10  10  10   0
-- End Changed Discussion --

&&

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

$$

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