518
FXUS64 KMRX 171139
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
739 AM EDT Sat May 17 2025

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 151 AM EDT Sat May 17 2025

Key Messages:

1. A line of strong to severe storms will move through the region
overnight. A Tornado Watch is in effect for most of the region.

2. Rain and clouds will clear out by mid morning as a cold front
moves through.

Discussion:

Not much has changed in regards to severe storm potential overnight.
A line of strong to severe storms will be moving into the region
within the next couple of hours. Two discrete supercells have
produced tornadoes in Southeast Kentucky. Mesoanalysis shows
effective shear around 60 knots and 0-1 km shear 35 knots. Isolated
tornadoes will be possible. Damaging straight-line winds will be the
main threat.

In the upper levels, nearly zonal flow will be over the region as a
closed low moves through the Great Lakes Region and a ridge is over
the Gulf. At the surface, a cold front will be moving through the
region this morning. Winds will become more westerly and dew points
will be dropping after noon behind the front. Rain and clouds will
clear out by mid morning. Westerly winds will be a bit gusty
especially in SW Virginia and NE Tennessee, closer to the upper low.
Tonight will be dry and uneventful.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 151 AM EDT Sat May 17 2025

Key Messages:

1. Mainly diurnal showers and storms Sunday and Monday.

2. The best chance for significant rain and storms will be Tuesday
into Wednesday as a strong system moves through.

Discussion:

By Sunday a ridge begins to build into the Southeast, TN and Ohio
Valleys. Sunday and Monday may see some showers and thunderstorms
mainly in the afternoon as a boundary over the Southeast lifts
northward by Monday. By Tuesday, a closed low moves into the
Midwest. A surface low will move through the Ohio Valley Tuesday
evening bringing a cold front through the region by Wednesday
morning. Increasing chances for showers and storms with this system
Tuesday into Wednesday. This will be the best chance for severe
storms in the extended forecast period. Beyond Wednesday there is
more uncertainty in the guidance. GFS has drier weather and the Euro
has a cut-off low over the Great Lakes and Northeast bringing
lingering rain chances.

&&

.AVIATION...
(12Z TAFS)
Issued at 737 AM EDT Sat May 17 2025

Wx and any associated CIG have departed all terminals this morning.
VFR will dominate today with clearing conditions and
lifting/thinning cloud cover. However, SWly gusts will continue at
TYS and TRI for the afternoon before decreasing tonight.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             87  65  84  66 /  20  10  50  30
Knoxville McGhee Tyson Airport, TN  83  62  81  63 /  10  10  30  20
Oak Ridge, TN                       85  61  82  62 /  10   0  30  20
Tri Cities Airport, TN              80  57  79  57 /  10   0  10  10

&&

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

$$

SHORT TERM...McD
LONG TERM....McD
AVIATION...KS