536
FXUS64 KMRX 071758
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
158 PM EDT Tue Oct 7 2025

...New DISCUSSION...

.KEY MESSAGES...
Updated at 131 PM EDT Tue Oct 7 2025

- Beneficial rainfall through early Wednesday morning. Rainfall of
  1/4 to 1/2 inch across much of the area.

- Lows are expected to drop into the mid to upper 30s across the
  higher elevations of the far east Tennessee mountains for the
  latter half of the week.

- More fall-like temperatures and dry weather expected from Thursday
  onwards through this weekend. A slight warming trend Sunday
  into next week.

&&

.DISCUSSION...
Issued at 131 PM EDT Tue Oct 7 2025

Currently, an area of light rain is moving across the northern
half of Tennessee and southwest Virginia. This is due to a 30
knots 850mb jet producing isentropic lift across much of the area
today. Rainfall amounts have been light and will move north of the
area this afternoon.

For this evening, the jet dynamics associated with 300mb jet
streak over the Ohio valley will have moved northeast of the area.
A pre-frontal trough over middle Tennessee will move into the
Plateau and east Tennessee. This boundary along with marginal
instability (CAPES of 500-750) will produce scattered showers and
embedded thunderstorms.

For tonight, models are in agreement with isentropic forcing in
the 305-310K layer. As the frontal boundary approached the area a
band of showers and possibly thunder will move across the region.
Overall, rainfall amounts will average 1/4 to 1/2 inch.

For Wednesday, showers will end with drier air moving back into
the region with sky cover diminishing. Mainly the far east
Tennessee mountains will have a chance of showers in the afternoon
and evening.

For Thursday, another wave moving into the Tennessee valley and
southern Appalachians will produce an inverted surface trough
across the area. There is a slight chance of showers mainly in the
mountains and southeast Tennessee, otherwise dry.

For Friday through early next week, ensemble analysis and
deterministic models are in agree with an upper ridge over the
mid-section of the nation with and upper trough along the east
coast. Overall dry conditions and more seasonal fall temperatures
are expected. Lows for the latter half of the week will fall into
the mid to upper 30s across the higher elevations of the far east
Tennessee mountains.

A gradual warming trend is expected early next week as the upper
ridge builds into the Tennessee valley.

&&

.AVIATION...
(18Z TAFS)
Issued at 120 PM EDT Tue Oct 7 2025

Main concerns are periods of showers and possibly a thunderstorm
through early Wednesday morning and IFR ceilings for early
Wednesday morning.

Showers with light rain will continue to move across the TAF sites
through early evening. A brief break in the showers this evening
before another round of showers and possibly a thunderstorm
overnight through early Wednesday morning.

Boundary layer becomes saturday early Wednesday morning as a
frontal boundary approaches the area. LIFR ceilings are expected.

For Wednesday morning, convective activity will move east with
drier air slowly advecting into the area allowing flight
conditions to improve.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             68  80  58  72 /  80  10  10  10
Knoxville McGhee Tyson Airport, TN  67  76  55  73 /  90  20  10   0
Oak Ridge, TN                       66  75  53  72 /  90  10   0  10
Tri Cities Airport, TN              63  72  48  70 /  80  40   0   0

&&

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

$$

DISCUSSION...DH
AVIATION...DH