645
FXUS64 KHUN 221133
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
633 AM CDT Wed Jul 22 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 633 AM CDT Tue Jul 22 2026

 - Unsettled weather will continue for the remainder of the week,
   with daily chances of showers and thunderstorms, as a frontal
   boundary remains stationary south of the Tennessee Valley.

 - Into the late week, locally heavy rainfall could occur near and
   south of the Tennessee River, as well as near and east of
   Interstate 65 corridor.

&&

.NEAR TERM...
(Today)
Issued at 100 AM CDT Wed Jul 22 2026

The line of strong to severe storms moving south from central
Tennessee continues to overall weaken, except where it is pushing
into more abundant CAPE in SW Tennessee and northern Mississippi
SBCAPE in those areas still 2500 to 4000 J/KG). Newest mesoscale
models continue this trend as well.

That being said, wind shear over 30 knots is mainly in place near
the TN/AL border and further north. SBCAPE over northern Alabama
and southern middle Tennessee is still around 1500 J/KG to 2000
J/KG (Mainly NW AL for higher SBCAPE). So, parameters are still in
place over southern middle Tennessee such that a low chance
severe threat is still in place. This threat in most guidance
shifts east with time and dissipates towards or before daybreak
on Wednesday as we lose more instability. We may have to watch
Lincoln, Moore, and Franklin counties in TN for possible flash
flooding through daybreak given potentially high rainfall rates
that could be realized with some training of stronger storms
possible over those areas. Lows tonight will be on the warm side
only dropping into the lower to mid 70s.

We should see a lower coverage of showers and storms (30-40%)
after daybreak in southern middle Tennessee Wednesday morning
before increasing in coverage to between 40 and 60 percent in the
afternoon and early evening hours (especially east of the I-65
corridor. Given very high PWAT values through the day well over 2
inches, some flash flooding could occur in southern middle
Tennessee and some areas east of the I-65 corridor into the early
evening hours. However, as we lose stronger shear this morning, no
additional severe thunderstorm development is expected.

&&

.SHORT TERM...
(Wednesday night through Friday)
Issued at 933 PM CDT Tue Jul 21 2026

Slightly cooler air north of the front should filter across the
area Wed night, with lows a bit more comfortable from the mid 60s
to around 70. The aformentioned frontal boundary will become
stationary south of the Tennessee Valley from Thu into the
upcoming weekend. The presence of this front will keep medium to
high chances of showers/thunderstorms, mainly for areas south of
the Tennessee River and east of I-65. Low to medium rain chances
are expected elsewhere. Some of the showers more to our south and
east could be locally heavy. High enough rainfall amounts will be
sufficient to warrant low chances of excessive rainfall and the
potential for flash flooding.

Cooler conditions will be noted Thu with highs in the mid/upper
80s. More comfortable lows will continue as well Thu night with
lows in the mid 60s to around 70. A tad warmer Fri with highs in
the mid 80s to around 90.

&&

.LONG TERM...
(Friday night through Tuesday)
Issued at 933 PM CDT Tue Jul 21 2026

The long term period will largely be influenced by an upper level
ridge and subsequent sfc high pressure system looming over the Deep
South and slowly shifting eastward into the lower Mississippi Valley.
A few features to watch will be how remnants of Tropical Storm Bertha
interact with a cold front south of our area. How these two features
interact will largely dominate the forecast for Friday into Sunday.
We currently have low to medium rainfall chances through that time
period and are outlooked for a Marginal risk (level 1 of 4) for flash
flooding from the Weather Prediction Center. If the front shifts over
the area and stalls, the flooding threat will increase. However,
there is still too much uncertainty to dive into details as it is
several days out. If you have outdoor plans early this weekend, it`s
highly encouraged to check back in for updates. Otherwise, as the
aforementioned ridge shifts eastward, dry weather should return to
the area early next week along with a warming pattern as highs begin
to climb back into the mid to upper 90s. Additional heat products
will likely need to be considered if trends continue.

&&

.AVIATION...
(12Z TAFS)
Issued at 632 AM CDT Wed Jul 22 2026

Predominantly VFR conditions should continue at both terminals
through 17Z. A PROB30 group was included though to account for
possible -TSRA impacting the terminals between 13Z and 17Z as a
front approaches the area. Expect CIGS to break up around 17Z, with
another prob30 group for -TSRA and MVFR CIGS/VSBYS. Guidance seems
to oscillate the front back to the north this evening. This should
bring higher PoP back into the KHSV terminal in particular. For
now, added a tempo group to account for this between 23/03Z and
23/07Z. Lower rainfall chances are possible further west at KMSL,
so only a PROB30 group to -TSRA activity and MVFR CIGS/VSBYS was
added there between 08Z and 12Z.

&&

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

$$

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