831
FXUS64 KMRX 200709
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
309 AM EDT Mon May 20 2024

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

.SHORT TERM...
(Today and tonight)
Issued at 306 AM EDT Mon May 20 2024

Key Messages:

1. Most locations will be dry, but there may be a few isolated
showers/thunderstorms today mainly eastern mountains.


Discussion:

Upper ridging over the region will gradually slide east, and surface
high pressure will continue to extend into our area during the short
term period.  Most locations will be dry with plenty of sunshine,
but there may be enough modest instability for a few isolated
showers and thunderstorms to develop today over SW NC and the
eastern TN mountains. Any weak convection is expected to dissipate
by tonight. Temperatures will generally run around 3-5 degrees above
seasonal normals both today and tonight.

&&

.LONG TERM...
(Tuesday through Sunday)
Issued at 306 AM EDT Mon May 20 2024

Key Messages:

1. Dry and warm weather to continue through Wednesday, with only
isolated thunderstorm potential generally in the higher elevations.

2. Unsettled pattern with multiple rounds of showers and storms
possible Thursday through the weekend.

Discussion:

Starting off the period, low level ridging anchored along the
Appalachian Mountains will provide for warm and dry weather for
most, with only a low chance of a thunderstorm in the higher
terrain Tuesday and Wednesday afternoons.

As Thursday enters the picture, the long mentioned front will be
washing out in the periphery of the Ohio River, bringing a return
for higher rain chances. The bulk of the storms daytime Thursday
look likely to be draped to our north along the frontal boundary,
however with the close proximity of the front, ensemble guidance
still has 30% to 60% chance PoPs by the afternoon, weighted towards
the northern Cumberland Plateau and northeastwards, closest to the
frontal zone. Afterwards rain chances remain elevated as we go into
Friday and the weekend, as a series of weak shortwave disturbances
swing through in the flow providing opportunities for additional
rainfall. GEFS ensemble probabilities have backed off slightly for
greater than 2 inches of rain through the weekend, with the Euro
mean more pessimistic at only 50% chance for an inch of QPF. GFS
appears to be strongest with the Friday shortwave to a point that a
strong thunderstorm would be possible, but it also appears to be an
outlier in the strength of that shortwave versus the Euro and both
ensembles. Because of that outlier nature, for now there`s no
particular concern for any significant weather, severe or
hydrological.
&&

.AVIATION...
(06Z TAFS)
Issued at 1231 AM EDT Mon May 20 2024

Possible fog development early in the period is the primary
aviation weather concern, and right now the most likely location
to be impacted appears to be TRI. For now will include a few
hours of MVFR vsby there toward sunrise, but lower conditions are
possible as is fog development elsewhere. Other than the possible
fog, VFR conditions are expected for the period all sites.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             86  64  87  65 /  10   0   0   0
Knoxville McGhee Tyson Airport, TN  84  62  85  64 /  10   0  10   0
Oak Ridge, TN                       86  62  86  64 /  10   0  10   0
Tri Cities Airport, TN              84  57  83  61 /  10   0  20   0

&&

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

$$

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