800
FXUS64 KHUN 151532
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1032 AM CDT Sat Aug 15 2026

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

.KEY MESSAGES...
Updated at 1032 AM CDT Sat Aug 15 2026

 - Dangerous heat will impact the Tennessee Valley through the
   middle of next week, with Major (Level 3/4) to Extreme (Level
   4/4) heat impacts forecast.

 - A Heat Advisory is in effect for all of northern Alabama and
   southern middle Tennessee through 7 PM Monday, with extensions
   potentially into the middle of next week.

 - A Marginal (1 out of 5) risk for severe thunderstorms is
   forecast across Northern Alabama near and east of I-65 Monday
   afternoon.

&&

.NEAR TERM...
(Rest of Today and Tonight)
Issued at 1032 AM CDT Sat Aug 15 2026

An an upper level ridge continues to sit to our west, mostly dry
conditions with above-normal temperatures will influence the
Tennessee Valley. Our primary concern today will be heat as highs
reach the upper 90s with heat indices in the 103-109 degree range.
There is a low chance (less than 20%) in which some area of NW AL
reach 100 degrees this afternoon. A Heat Advisory remains in
effect through both today and tonight to account for the dangerous
temperatures. Be sure to remain hydrated and seek shade when
outdoors. Otherwise, a low chance (10% or less) of thunderstorms
exists this afternoon in portions of far NE AL. If a thunderstorm
is realized, it will present a low chance of gusty winds up to 50
mph.

&&

.SHORT TERM...
(Sunday through Tuesday)
Issued at 1032 AM CDT Sat Aug 15 2026

Under the aforementioned existence of an upper level ridge, the
Tennessee Valley will remain in a heightened risk area for heat
through at least early to mid next week. Our current Heat Advisory
for all of northern AL and southern middle TN is valid through
Monday evening, however, there is a low-medium chance it will get
extended in time through Tuesday in future updates. Current highs
through this period are forecast to be in the upper 90s with heat
indices up to 110 degrees. Monday continues to be forecast as the
hottest day of the period of concern, with heat indices nearing
Extreme Heat Warning criteria. One factor to consider on Monday
will be how much cloud cover associated with increased rain
chances affect the temperatures. We are currently outlooked by the
Storm Prediction Center for a Marginal risk (level 1 of 5) for
severe weather Monday afternoon into the evening due to a risk for
downbursts (and subsequent damaging winds) in NE AL and southern
middle TN. Therefore, confidence remains higher in Extreme Heat
Warning criteria being met along and west of I-65. Be sure to keep
up with the latest forecast as we head into early next week and
remain hydrated as heat continues to be the primary concern.

&&

.LONG TERM...
(Monday night through Friday)
Issued at 929 PM CDT Fri Aug 14 2026

The center of the ridge will begin to gradually flatten through
the week, but Major (Level 3/4) heat impacts will continue
through the work week. This is due to highs in the mid 90s and
dewpoints in the mid to upper 70s creating heat index values in
excess of 105 degrees each day. In addition to the heat, low
chances (20-30%) of diurnally driven showers and thunderstorms
will return to the forecast each afternoon Tuesday through Friday,
thanks to the deep moisture in place. The one caveat would be if
the ridge shifts a little further to the west, placing the area
under northwest flow aloft. Should this play out, we may be more
under the threat for MCS activity that rides along the edge of the
ridge. We`ll have to watch this in the days to come. Overall, hot
and humid weather for the foreseeable future.

&&

.AVIATION...
(12Z TAFS)
Issued at 627 AM CDT Sat Aug 15 2026

Under mostly clear skies, patchy fog has formed across portions of
the TN Valley. Some of this fog was impacting KMSL, with local
VSBY reductions to 1SM. This fog should dissipate in the next hour
or so as the sun rises. Strong daytime heating should produce few
to scattered cumulus with cloud bases above 5kt ft. The heating
of a more moist airmass over far NE AL could lead to isolated
shower and thunderstorm development mainly this afternoon. Light
winds early in the period will become westerly 5-7kt in the late
morning and afternoon, with winds becoming light after dusk.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Heat Advisory until 7 PM CDT Monday for ALZ001>010-016.

TN...Heat Advisory until 7 PM CDT Monday for TNZ076-096-097.

&&

$$

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