145
FXUS64 KHUN 160037
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
737 PM CDT Tue Sep 15 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 244 PM CDT Tue Sep 15 2026

 - A Heat Advisory is in effect through 8 PM Wednesday for much
   of the forecast area.

 - Moderate (Level 2/4) NWS HeatRisk values are expected for the
   majority of the forecast period. However, Major (Level 3/4)
   values are expected across parts of northwest and north-central
   AL (as well as southern Middle TN) through Friday.

&&

.NEAR TERM...
(Tonight)
Issued at 244 PM CDT Tue Sep 15 2026

A troughing west and ridging east pattern continued over the
Lower-48. Strong upper level ridging was present over the Deep
South and Southern Appalachians, with 500mb maximum heights around
598 decameters. This ridge should strengthen to ~600 decameters
during the overnight into Wed night. Surface high pressure off
of the New England coast was providing a southerly flow across the
area. 2 PM temperatures have risen into the mid 90s. Dewpoints
have mixed even more than earlier anticipated, from the low/mid
70s earlier this morning into the mid/upper 60s. This has
decreased heat index values into upper 90s to 103 degrees. The
area will be close to, if not over heat advisory levels into the
late afternoon.

Daytime heating produced clouds should fade as we go into the
evening. Night time lows should cool into the upper 60s northeast
Alabama to low/mid 70s near large bodies of water. Patchy fog late
tonight cannot be ruled out, but am not forecasting it given low
confidence.

&&

.SHORT TERM...
(Wednesday through Thursday night)
Issued at 909 AM CDT Tue Sep 15 2026

The aformentioned upper ridge will slowly build towards the SW as
we go through the midweek. Thus similar temperatures are expected,
with highs in the mid/upper 90s. Dewpoints should again mix to
around 70 degrees, which should keep heat index values just below
Advisory threshold of 105 degrees. We will evaluate this thinking,
if the new NBM coming in in the next couple of hours trend
warmer, we will extend the Heat Advisory into Wednesday. An
otherwise repeat forecast with lows mainly in the 70s Wed night.
Another hot and dry day is forecast for Thu with highs in the
mid/upper 90s, and dewpoints mixing down into the upper 60s to
around 70, which would keep apparent temperatures just below
advisory criteria. Even though we may not have official advisories
active, area residents should still practice heat alleviation
tactics, like avoiding direct sun exposure for as much as
possible, drinking plenty of water, and taking frequent breaks.

&&

.LONG TERM...
(Friday through Monday)
Issued at 1031 PM CDT Mon Sep 14 2026

Late this week the anchored ridge across the Southeast will
continue to retrograde and weaken as a cut off low moves westward
across Florida. What remains of the ridge will keep around warmer
than normal temps in place with highs in the mid to upper 90s and
heat index values around 100 degrees Friday and Saturday.

This weekend, the low will continue to slide westward. However,
models are now not as certain on what the path and trajectory of
the low will be as it is suggesting it slows down the westward
progression on Sunday and stalls it out to our south through
Monday. This pattern leads to a greater assumption that the front
well to our north that drapes over into the OH Valley and Mid
Atlantic will not make it through the TN Valley. The persistent
sfc high along the east coast will cause it to become more of a
wedge front for us on Sunday into Monday. Temps and POPs on Sunday
and Monday will depend a lot on the pattern than ends up taking
shape. However, there should be a downward temp trend with
models favoring highs "only" in the 80s on Monday as medium rain
chances (40-60%) move in.

&&

.AVIATION...
(00Z TAFS)
Issued at 737 PM CDT Tue Sep 15 2026

Scattered patches of high-based Cu will continue to shift north-
northwestward across the forecast area early this evening, within
a southerly flow regime of 10-20 knots aloft. However, we expect
skies to clear later this evening, with development of patchy
BR/FG likely to occur btwn 10-13Z (mainly in wind-sheltered
valleys east of HSV). Strong heating of the boundary layer will
support redevelopment of few-sct high-based Cu by 15Z, with a few
aftn SHRA/TSRA expected to develop from the Cumberland Plateau of
Middle/East TN southward into northeast AL. Sfc winds will remain
from the S-SE thru the period, with prevailing speeds arnd 5 kts.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...

AL...Heat Advisory until 8 PM CDT Wednesday for ALZ001>009.

TN...Heat Advisory until 8 PM CDT Wednesday for TNZ076-096-097.

&&

$$

NEAR TERM...RSB
SHORT TERM...RSB
LONG TERM...JMS
AVIATION...70/DD