-- Discussion containing changed information from previous version are highlighted. --
927
FXUS64 KMRX 261454
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
1054 AM EDT Wed Mar 26 2025

...New UPDATE...

.UPDATE...
-- Changed Discussion --
Issued at 1034 AM EDT Wed Mar 26 2025

Growing concerns about fire danger this afternoon and evening
primarily in the East Tennessee mountains and foothills and the
North Carolina counties. A Red Flag Warning has been issued for
these areas through this evening. Elsewhere, a fire danger
statement continues through this evening.

Relative humidity values will drop into the 20 percent range for
most of the area this afternoon. In addition, west to northwest
winds between 10 to 15 mph with gusts up to 25 mph are expected.
Gusty winds begin to pick up around noon and should subside by
sunset. Winds will be higher in the higher elevations of the East
Tennessee Mountains with gusts up to 30 mph possible.

Otherwise, no significant changes to the forecast for today. Sunny
and dry conditions expected this afternoon.
-- End Changed Discussion --

&&

.SHORT TERM...
(Today and tonight)
Issued at 349 AM EDT Wed Mar 26 2025

Key Messages:

1. Enhanced Fire Danger Statement today for all areas due to low RH
and gusty winds.

2. Gusty winds up to 25 mph for valley areas today. Wind gusts up to
35 mph across the higher elevations of the east TN mountains.

Discussion:

A small and weak disturbance will rotate through the longwave trough
again today. This will only affect our northern areas and will only
result in a slight increase in cloud cover, no showers are expected.

Otherwise, dry and warm today with gusty afternoon winds and low
minimum RH. Yesterday`s dewpoints ended up being much lower than
forecast. For this reason, will go with the lower guidance values
for today using a blend of HRRR, NBM 10, and NBM. This will
yields min afternoon RH values in the mid to upper 20s across much
of the area. Winds won`t be as gusty as yesterday. However,
breezy winds are still expected as a good pressure gradient still
exists between the long wave trough to our northeast and high
pressure to our west. Expect wind gusts up to 25 mph for valley
locations and up to 35 mph across the highest east TN mountain
tops.

Due to the winds and low RH values, near Red Flag Conditions are
expected. For now though, an Enhanced Fire Danger statement will be
in effect today and until this evening. It`s possible that some
areas may get upgraded to a Red Flag Warning with the morning
forecast update around 10:00 AM.

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 349 AM EDT Wed Mar 26 2025

Key Messages:

1. Warming conditions begin Thursday and extend through the weekend.

2. Light rain chance Thursday night and Friday with weak disturbance
moving through upper flow.

2. Warming trend continues Friday as ridging builds in aloft and
surface high pressure brings return to a southerly flow to the
region.

4. Strong storm system will bring potential of mountain wave high
winds, heavy rainfall and thunderstorms to the region late Sunday
into Monday afternoon.

Discussion:

The extended period will start with a couple of weak disturbances in
the upper flow as a building upper ridge shifts the colder air to
the north.

Light rain chances possible Thursday night with the first weak
system and then again Friday with the second one. The upper ridge
will be building north as the weak systems move east southeast with
the upper flow affecting mainly the Ohio Valley Thursday and then
north and northeast sections Thursday night and again Friday.
Temperatures will still be warmer Thursday compared to today but be
held down by clouds and some light rain in the northeast, especially
later Thursday. Highs in the northeast will be below normal with
upper 50s to lower 60s but much warmer central and south in the
upper 60s to mid 70s. Friday looks much warmer even with more clouds
heights are building with highs in the 70s.

After the weak systems moves through, the upper ridge will become
the main weather maker. Another weak shortwave in flow will pass
through the region later Saturday and Saturday night and should
trigger scattered showers and thunderstorms by Saturday night. There
looks to be a break in the convection Sunday before more convection
moves through Sunday night.

The more significant convective event is forecast to begin affecting
the eastern Tennessee Valley Sunday into Monday, GFS and Euro models
still have significant differences in strength of the upper low as
it moves east across the US Sunday. The better chances for severe
weather remain to the west Sunday but the track and strength of the
surface low determines if the setup will be right for a mountain
wave wind event. Subtle differences in low level airflow and
available instability are difficult to forecast still 5 days out so
still in the monitor stage. Both models bring the best chance for
heavy rainfall and severe weather through late Sunday and Monday
morning with the cold front moving through the area until Monday
morning into mid afternoon. Behind the front an upper low develops
to the north so only a brief break Monday afternoon before the upper
low over the Ohio Valley brings yet more rain to most of the region
Monday night into Tuesday before higher pressure builds back in late
Tuesday and Tuesday night.

For fire weather, higher minimum RH values are expected Thursday and
Friday especially north with more clouds and a few showers. Winds
will be lighter Thursday and increase Friday into Saturday before
moisture return overcomes the warmer airmass Saturday. The
precipitation Thursday night and Friday will not be significant but
consistent warm temperatures will mean more vegetation is leafing
out and growing reducing the fire threat across the area.

&&

.AVIATION...
(12Z TAFS)
Issued at 726 AM EDT Wed Mar 26 2025

VFR at all sites through the period. Another day of breezy
afternoon winds with gusts to around 22kts out of the west to
northwest. Gusty winds subside by this evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             70  43  74  52 /   0   0   0   0
Knoxville McGhee Tyson Airport, TN  64  39  68  51 /   0   0  10  20
Oak Ridge, TN                       64  38  68  50 /   0   0  10  20
Tri Cities Airport, TN              57  34  63  45 /   0   0  10  40

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
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NC...Red Flag Warning until 8 PM EDT this evening for Cherokee-Clay.

TN...Red Flag Warning until 8 PM EDT this evening for Blount Smoky
     Mountains-Cocke Smoky Mountains-East Polk-Johnson-Sevier
     Smoky Mountains-Southeast Carter-Southeast Greene-Southeast
     Monroe-Unicoi.

VA...NONE.
-- End Changed Discussion --
&&

$$

SHORT TERM...
LONG TERM....TD
AVIATION...