516
FXUS64 KMRX 291907
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
307 PM EDT Wed May 29 2024

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

.SHORT TERM...
(This evening through Thursday)
Issued at 257 PM EDT Wed May 29 2024

Key Messages:

1. Dry weather with patchy fog possible tonight. Tomorrow is
slightly cooler but overall pleasant and dry.

Discussion:

Satellite this afternoon depicts a lot of puffy cumulus clouds
floating on by in the northwest flow. Winds are gusting to their
usual 20 to 30 mph with the mixed atmosphere today, those will calm
to light winds tonight. High resolution guidance has a couple spotty
returns through this evening, and trends have been to be less
vigorous than yesterday. Expect any light return to result in
virga, given the dry lower atmosphere across the region.

Tonight into tomorrow the dry weather pattern will continue. Winds
aloft look to pivot to more northerly flow under the upper trough,
which brings in a slightly cooler airmass in. Tomorrow morning
patchy fog is possible in northern Tennessee into southwest
Virginia, and HREF guidance keeps some low clouds around in the
morning. This, coupled with the slightly cooler airmass, should
result in slightly cooler afternoon highs tomorrow.

&&

.LONG TERM...
(Thursday night through next Wednesday)
Issued at 257 PM EDT Wed May 29 2024

Key Messages:

1. Dry weather will continue through Friday night.

2. Chances for showers and thunderstorms start to creep back into
the region starting Saturday afternoon. Rain chances to continue
into the middle part of next week.

Discussion:

A narrow upper ridge just to our west to start will build in
Thursday night into Friday.  We will see dry weather continue
through at least Friday night with near to below normal
temperatures. Relative humidity values will be low Friday afternoon.

By Saturday, the first in a series of upper level short waves is
forecast to be approaching.  This first wave is not expected to have
much moisture to work with, so we have just some low PoPs in the
forecast for Saturday afternoon across mainly southern and western
portions of the area. While the models are in decent agreement on
the timing of this first wave, beyond that there is poor agreement
and consistency which is not surprising given the typical model
difficulties in handling these types of features in the latter
portions of the forecast period. The ensemble approach of the NBM
shows chances for showers and storms for the remainder of the
forecast from Saturday night through Wednesday. GEFS ensemble data
shows modest median SBCAPE values overall although they do increase
a bit for the latter periods (as does the spread), and mean deep
layer shear is generally weak. While a few strong to severe storms
may occur, right now the severe storm threat looks to be on the low
side overall for the period. However, some of the models are hinting
at a significant cold front approaching by Wednesday, which may
provide a more favorable environment for stronger storms if this
does occur.

Temperatures will show an overall warming trend, with highs Sunday
likely to be below normal but by late in the period temperatures are
expected to be above normal across the area.

&&

.AVIATION...
(18Z TAFS)
Issued at 129 PM EDT Wed May 29 2024

VFR TAFs through the period, winds should gust 15 to 25 knots
across most or much of the valley this afternoon before weakening
and shifting this evening. Spotty light showers are possible again
from now until early tonight, but low level dry air preventing
most rain precludes mention in the TAFs. Patchy fog near TRI is
possible between 09z and 12z, but as of now not expecting any VIS
restrictions at TRI.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             57  81  57  83 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  53  77  53  78 /   0   0   0   0
Oak Ridge, TN                       53  77  53  79 /   0   0   0   0
Tri Cities Airport, TN              50  72  45  76 /   0   0   0   0

&&

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

$$

SHORT TERM...Wellington
AVIATION...Wellington