Erwin, Tennessee Weather Forecast Discussion

333
FXUS64 KMRX 051754
AFDMRX
Area Forecast Discussion
National Weather Service Morristown TN
154 PM EDT Sun Oct 5 2025
...New DISCUSSION...
.KEY MESSAGES...
Updated at 132 PM EDT Sun Oct 5 2025
- Dry weather will continue through Monday. A 40-70% chance for
  showers and a few storms make a return Tuesday and Wednesday.
- Temperatures will begin the period unseasonably warm.
  Temperatures 5 to 10 degrees above normal. More seasonal
  conditions are anticipated by the latter half of the week.
&&
.DISCUSSION...
Issued at 132 PM EDT Sun Oct 5 2025
Currently, increasing moisture and isentropic lift is spreading
cloud cover into southeast Tennessee, southern Plateau, and far
east Tennessee mountains. HREF, REFS, and latest GFS show a chance
of light showers or sprinkles over southeast Tennessee. Probabiliy
of measurable precipitation is quite low. Otherwise, increasing
clouds is expected.
For tonight and Monday, upper and surface ridging will remain over
the southern Appalachians. Easterly flow in much of the southern
Appalachians will produce downslope into much of the region except
for possibly the southeast.
For Monday night through Wednesday, ensemble cluster analysis and
deterministic models show ridging weakening and forced south as a
series of short-waves and associated moves across the Ohio valley.
As an upper trough moves into the northeast/mid-Atlantic states by
Wednesday associated frontal boundary will move into the Tennessee
valley and southern Appalachians. Jet dynamics, fronto-genetic
forcing, and leading isentropic lift will produce an increasing
chance of showers from Tuesday through Wednesday.
Ensemble CAPE shows values of 500-700 so enough instability for a
chance of thunderstorms. Environment is not supportive of strong
to severe storms.
Due to proximity of stronger forcing over the Ohio valley, the
greatest QPF will be over southwest Virginia and northern sections
of Tennessee where amounts of 0.50-0.75 inch expected. For areas
along and south of interstate 40, 0.25-0.5 inch anticipated.
For Thursday, an inverted surface trough is expected over the area
with a chance showers mainly for areas along and south of
interstate 40. Confidence is low.
For Friday into next weekend, ensemble analysis and deterministic
models are in disagreement and forecast confidence is low.
Currently, greatest probability is for dry northwest and surface
ridging producing dry conditions.
&&
.AVIATION...
(18Z TAFS)
Issued at 110 PM EDT Sun Oct 5 2025
Southeast flow into the southern Appalachians is producing
isentropic lift with increasing clouds and showers noted across
northern Georgia. CHA and TYS could see a light shower or
sprinkles through 00Z. Ceiling at CHA will lower to around 5kft
this evening.
Otherwise, VFR conditions anticipated at all TAF sites with a good
deal of high and mid-level clouds.
Winds will be brisk easterly between 5 to 10 kts through early
this evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             65  82  67  84 /  10  10  10  20
Knoxville McGhee Tyson Airport, TN  60  83  64  83 /  10  10  10  20
Oak Ridge, TN                       59  83  64  81 /  10  10  10  40
Tri Cities Airport, TN              56  82  58  80 /   0  10  10  30
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DISCUSSION...DH
AVIATION...DH

NWS MRX Office Area Forecast Discussion