934
FXUS64 KHUN 152228
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
528 PM CDT Wed Jul 15 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 953 AM CDT Wed Jul 15 2026

 - Diurnally driven showers and thunderstorms will continue
   through Thursday with lightning and locally heavy rainfall the
   primary threats. Rain chances shift primarily into our eastern
   forecast area on Friday.

 - Temperatures will remain slightly below normal through Thursday
   before gradually warming through the weekend.

 - Heat Risk will reach the moderate category over the weekend.
   Heat index values are forecast to peak in the upper 90s to
   lower 100s.

&&

.NEAR TERM...
(Tonight)
Issued at 131 PM CDT Wed Jul 15 2026

No major changes from the previous forecast discussion. Showers
remain scattered in nature throughout the TN Valley with a low
chance of lightning in addition to heavy rainfall. Temperatures
have warmed into the mid 80s in most locations so far under
scattered cloud cover.

Previous Discussion:
The low pressure system that has caused continued rain chances
each day has shifted westward into the lower Mississippi Valley,
decreasing rain chances today and keeping future storms more
spatially scattered. Diurnal heating will allow thunderstorm
development this afternoon, however, weak shear will dissuade any
organized convection and strong storms are unlikely. The primary
concern for storms will be heavy rainfall and lightning.
Otherwise, high temperatures are forecast to warm into the mid to
upper 80s today under scattered cloud cover. Another mostly dry
night is in store with lows dropping into the upper 60s to lower
70s. Patchy fog cannot be ruled out in areas where clearing cloud
cover occurs as light winds and low dew point depressions reside
over the area.

&&

.SHORT TERM...
(Thursday through Saturday)
Issued at 953 AM CDT Wed Jul 15 2026

Thursday, the pattern is rinse and repeat with afternoon
thunderstorm chances in response to diurnal heating. Friday,
thunderstorm chances increase and become more widespread as a
convergence boundary shifts over the Tennessee Valley. While shear
remains weak, DCAPE values around 800-1000 J/kg and MUCAPE of
1800+ J/kg will support the potential for locally gusty winds
along with heavy rainfall and lightning. As we go into the
weekend, an upper level trough shifts eastward through the Great
Lakes and subsequent storm chances become contained primarily to
the northeastern area of our region into the Appalachians. An
upper level ridge will coexist over the Deep South into the lower
Mississippi Valley, pushing warm/dry air into the western portions
of the area. As this ridge continues to move eastward, a warming
pattern will take over the Tennessee Valley. More on that in the
long term section below.

&&

.LONG TERM...
(Friday night through Tuesday)
Issued at 946 PM CDT Tue Jul 14 2026

As we head into the weekend an upper trough will dig east through the
Great Lakes region, increasing PoPs and thunderstorm chances across
the Appalachians digging south through eastern portions of the TN
Valley. As this happens, H85 upper ridging will bring warmer temps to
the area and combined with the humidity will bring an increasing
risk for dangerous heat as we head into next week. Medium chances for
rain will continue through the weekend before drier air is pushed
into the TN Valley on Monday. Highs will climb into the low to mid
90s through the extended period and combined with dewpoint temps in
the mid 70s will bring afternoon heat indices to the 99-105 degree
range, especially early next week. There are some model discrepancies
regarding the evolution of an upper trough that could bring a fairly
strong cold front into the area some time early to mid next week,
and with that comes some uncertainty on if an increased coverage of
rain and thunderstorms could curb a higher heat risk. At this range,
we will continue to emphasize a drier (capped PoPs at 30%) and warmer
forecast early next week with the main risk highlighted by a
moderate to major (levels 2 and 3 out of 4) HeatRisk.

&&

.AVIATION...
(00Z TAFS)
Issued at 528 PM CDT Wed Jul 15 2026

Isolated -SHRA will dissipate by 01Z. VFR conditions are expected
until late tonight when lower clouds and patchy FG are forecast to
develop. There is a high chance of ceilings of 010-015agl (MVFR)
at KMSL and KHSV from 11-16Z. Will reassess the FG potential this
evening for the next update, but confidence remains higher on
lower clouds than FG for the terminals. Ceilings will scatter and
lift to VFR by 16Z. There is a low chance of -SHRA and TSRA again
Thursday afternoon, but confidence remains too low to include in the
TAFs at this time.

&&

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

$$

NEAR TERM...HC
SHORT TERM....HC
LONG TERM....25
AVIATION...17