289
FXUS64 KHUN 260507
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1207 AM CDT Sun Jul 26 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1110 PM CDT Sat Jul 25 2026

 - Heat Risk increases to Moderate Risk (level 2 out of 4) on
   Sunday to Major Risk (level 3 out of 4) for parts of the area
   on Monday. For Tuesday, most locations will be at Major Risk
   (level 3 out of 4).

 - Shower and thunderstorm chances are increasing for Monday.
   Gusty winds may accompany these storms.

 - A cold front (preceded by thunderstorms) will bring a slightly
   cooler/drier airmass to the region for the end of the work
   week. Rain chances will increase once again early next weekend.

&&

.NEAR TERM...
(Rest of tonight and Sunday)
Issued at 1100 CDT Sat Jul 25 2026

A shortwave that crossed the region earlier today helped to
instigate shower and thunderstorm development that brought a swath
of ~1-2 inches of rainfall to some areas. The latest guidance
suite in addition to satellite imagery suggests this feature is
just to the south of the area late this evening. Shower activity
diminished quickly in its wake amidst the rain-cooled local air
mass in place. Ambient flow aloft impinging on the cooler air mass
and experiencing lift has generated low stratus across parts of
the area late this evening, while areas of fog could also be
observed developing in satellite imagery in the eastern valleys.
This will likely continue overnight, with perhaps more fog
expected especially in areas that received appreciable rainfall on
Saturday. A few showers and perhaps a storm could develop
overnight along an old stalled boundary cutting across the area,
but chances are low (~10-30%).

On Sunday, a drier air mass aloft is expected to move into the
area. An increase in drier air aloft will aid in increased overall
sunshine/insolation, although some lower cu/stratocu may linger.
At the same time, PWs that were as high as ~2.3 inches on
Saturday, will decrease to ~1.5 inches or less. Without a strong
forcing mechanism, convection chances will be decreased (<10%),
and generally limited to smaller cells that may develop due to
differential heating or along old outflow boundaries. High
temperatures should be much warmer than on Saturday, with highs in
the low/mid 90s at most locations. WBGTs will also be around 86-88
F during the day. We are considering the issuance of a Heat
Advisory for Sunday which will be coordinated during the
overnight.

&&

.SHORT TERM...
(Sunday night to Tuesday)
Issued at 1100 PM CDT Sat Jul 25 2026

Early next week, and in fact, for much of the week, the pattern
across the CONUS will remain entrenched...featuring a broad sub-
tropical ridge centered over the SW and a trough along the East
Coast. The TN Valley will lie essentially at the trough/ridge
interface, although characteristic "wobbling" of the broad ridge
will lead to some changes in our weather over the period. For
Monday, a shortwave rounding the northern and then eastern flank
of the ridge, may move into the TN Valley. This is depicted in the
broader medium range guidance suite. This will be the fly in the
ointment so to speak for the issuance of any Heat Advisory for
Monday that would otherwise be warranted given sfc temp/dew point
expectations. However, with the presence of a possible MCS or
even a training of convection that looks plausible, the rain would
limit heating of course, but the potential instability could
produce strong thunderstorm activity. This will bear some watching
for the Monday morning/afternoon timeframe.

Otherwise for Tuesday, as the subtropical ridge is expected to
move and expand eastward towards the region, a plume of hot air
extending from the SW CONUS looks to sweep across the region.
Temperatures on Tuesday are currently forecast to reach the
mid/upr 90s at most locations, but 100 F degrees or higher is not
out of the questions. Heat indices could breach 110 F as well with
WBGTs at/above 90s in more urban locations.

&&

.LONG TERM...
(Tuesday night through Saturday)
Issued at 1100 PM CDT Sat Jul 25 2026

Extended range model data suggests that a developing surface low
will track eastward across the northern Mid-Atlantic states on
Tuesday night/Wednesday, in conjunction with an amplifying longwave
trough across the eastern CONUS. A cold front attached to the low
appears likely to drop southward through the TN Valley during this
timeframe, although details regarding specific timing are unclear at
this point. A warm/moist airmass is expected to be in place ahead of
the front, with steep low/mid-level lapse rates and CAPE to support a
couple of rounds of thunderstorms (perhaps an MCS Tuesday night
followed by additional convection more directly forced by the cold
front Wednesday). Furthermore, deep-layer NW flow of 20-30 knots will
exist within a contracted height gradient between the trough to our
east and a strong mid-level high over the southwestern CONUS, and
this could support a risk for damaging winds given the favorable
thermodynamic environment.

In the wake of the front, light-moderate northerly winds will advect
a cooler/drier continental airmass into the region, with dewpoints
briefly falling into the 60s an PWAT values falling to around or
slightly below 1" from Wednesday night-Thursday night (and perhaps
into Friday as well). By the end of the forecast period, deep-layer
SSW flow will return to the region as an amplifying shortwave trough
(traveling around the periphery of the ridge to our west) digs
southeastward into the Mid-MS/Lower-OH Valley region and a surface
low shifts eastward from the Red River Valley into the Arklamiss
vicinity. Rich moisture will return to the region as this occurs,
with an increase in the coverage of showers/thunderstorms expected
beginning late Friday night and continuing through Saturday.

&&

.AVIATION...
(06Z TAFS)
Issued at 1207 AM CDT Sun Jul 26 2026

Shortly after 6Z, lower MVFR ceilings look to filter into HSV and
linger through mid morning. Around 16Z they will begin to lift
with VFR conditions prevail through the remainder of the period.
The lower ceilings don`t look to make it to MSL, with VFR
conditions in place the whole TAF period.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&

$$

NEAR TERM...KDW
SHORT TERM....KDW
LONG TERM....70/DD
AVIATION...RAD