673
FXUS64 KHUN 181319
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
819 AM CDT Mon Aug 18 2025

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

.NEAR TERM...
(Rest of Today and Tonight)
Issued at 819 AM CDT Mon Aug 18 2025

Patchy fog that has formed has been primarily contained to areas
that received rainfall as well as in agricultural areas. This fog
will continue to dissipate over the next hour. An upper level
ridge will continue to try to work its way eastward into the
Tennessee Valley today with subsequent sfc high pressure allowing
mostly dry conditions throughout the area. Our primary concern
today will be heat as high temperatures reach the mid to upper 90s
with heat indices up to 107 degrees. The highest temperatures will
be primarily along and west of I-65, where we have a Heat Advisory
in effect through 8 PM Tuesday evening. We continue to urge
everyone to stay hydrated, limit strenuous outdoor activities,
wear light-colored clothing, and check on friends/family. There
will be little relief overnight as low temperatures drop into the
low to mid 70s.

&&

.SHORT TERM...
(Tuesday through Thursday)
Issued at 819 AM CDT Mon Aug 18 2025

Lack of synoptic forcing will keep rain chances low (30% or less)
through most of the short term period. If showers/storms develop,
they will be during the peak afternoon heating hours and will be
scattered in nature. Sufficient instability (sfc CAPE ~1000 J/kg)
and low level lapse rates (~9 C/km) will allow threats with any
storms to include frequent lightning as well as gusty winds up to
40-50 mph. Lack of wind shear should prevent any organized severe
development of storms. Heat will continue to be a concern through
at least Tuesday evening, during which our Heat Advisory remains
in effect for high temperatures in the mid to upper 90s and heat
indices up to 107 (primarily along and west of I-65). We drop
below Heat Advisory criteria Wednesday, however, it will still be
hot with highs in the 90s and heat indices up to 100-104 with
isolated areas up to 106. If these temperatures trend higher in
future forecast updates, the Heat Advisory may be extended. Be
sure to stay hydrated, limit strenuous outdoor activities, wear
light-colored clothing, and check on friends/family.

Wednesday into Thursday, weak upper level troughing and a cold
front stemming from the Great Lakes region is forecast to
influence the area. There is a low chance this front evolves into
an MCS, which would increase the risk for locally damaging winds
and heavy rainfall. We have low confidence in exact timing of this
at this moment due to some slight model disagreement. The timing
of this will also affect temperatures Wednesday if it moves in
earlier, and could result in cooler temperatures than forecast.
One thing is for certain: a slight cool down is forecast
afterwards as highs should decrease to the upper 80s to lower 90s
with heat indices topping out around 95-100 degrees.

&&

.LONG TERM...
(Thursday night through Monday)
Issued at 819 AM CDT Mon Aug 18 2025

An upper level trough continues to influence the area through the
weekend, bringing increased cloud cover as well as low to medium rain
chances daily. However, this will also result in decreased
temperatures as highs peak in the 80s throughout most of the area.
While we are still too far out to get into specific threats with
any potential thunderstorm development, storms will likely be
capable of producing heavy rainfall as PWATs are forecast to be
around 1.7-1.9", which is around the 75th to 90th percentile per
BMX sounding climatology.

&&

.AVIATION...
(12Z TAFS)
Issued at 629 AM CDT Mon Aug 18 2025

For the TAF, high pressure at the surface and aloft should control
the general weather situation across the Tennessee Valley.
Although patchy fog has formed over parts of the area east of
I-65, mostly clear skies and VFR conditions prevailed elsewhere.
Fog should dissipate within the next couple of hours as daytime
heating and mixing occur. Although very warm to hot conditions
are forecast, temperatures in the mid atmosphere also should be
warm, which should hamper convection development. Light winds
early in the TAF will become NE 5-7kt in the late morning and
afternoon, then become light again after dusk.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Heat Advisory until 8 PM CDT Tuesday for ALZ001>007-016.

TN...Heat Advisory until 8 PM CDT Tuesday for TNZ076-096.

&&

$$

NEAR TERM...HC
SHORT TERM....HC
LONG TERM....HC
AVIATION...RSB