Cullman, Alabama 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

826
FXUS64 KHUN 270005
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
705 PM CDT Tue May 26 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 904 AM CDT Tue May 26 2026

 - A Flood Watch for Flash Flooding is in effect through 10 PM
   Tuesday for Cullman, Morgan, Madison, Jackson, Marshall and
   Dekalb counties.

 - Medium to high chances for showers and thunderstorms continue
   across the Tennessee Valley into the weekend.

&&

.NEAR TERM...
(Tonight)
Issued at 137 PM CDT Tue May 26 2026

A broad area of low pressure across the Mid South and lower
Mississippi Valley and diurnal heating has generated several
clusters of showers and thunderstorms across central and southern
Alabama, which will continue to push northward into the Tennessee
Valley over the next 2-3 hours. Satellite imagery indicates some
breaks in the cloud cover, which has allowed most locations to
warm into the upper 70s to lower 80s as of 18z. Winds at the
surface have now largely veered to the SSW, with SW flow in the
mid to upper-levels, straightening hodographs per the latest VWPs
at HTX, GWX, and BMX. Still, with effective shear around 20-30 kts
and MLCAPE values around 500-1000 J/kg, this may allow for some
modestly organized thunderstorms, especially during the late
afternoon and early evening window (20-02z).

As noted in this morning`s discussion, the primary risk, by far,
continues to be locally heavy rainfall and a low chance for flash
flooding. Forecasted PWATS between 1.6"-1.7" are between the
95th-99th percentile per BMX/OHX sounding climatology. In
particular, locations in the Flood Watch (areas in Alabama along
and east of I-65) will be most favored for localized flooding in
slower moving convection where training occurs. Thus, we will
keep the Flood Watch in effect until 10 PM when these showers and
storms will generally wane overnight. Given the recent trends in
convection dissipating by the evening and guidance keeping
convection more diurnally driven later in the week, think this
Flood Watch can most likely be allowed to expire by 03z. With
dense cloud cover in place, it will again be a very warm/humid
night, with lows in the upper 60s.

&&

.SHORT TERM...
(Wednesday through Thursday)
Issued at 904 AM CDT Tue May 26 2026

A pretty similar pattern will persist Wednesday and Thursday
across the Tennessee Valley, though wind shear values will be a
bit lower both days. Convection will again be diurnally driven and
favored to develop along any lingering mesoscale boundaries from
the previous day`s convection. Heating should be sufficient enough
(with the southwesterly surface flow and enough breaks in the
clouds) to push temperatures into the low to mid 80s each
afternoon. MLCAPE values around 1000 J/kg will support a few
locally strong pulse thunderstorms during peak heating in the
afternoon and evening hours. However, the primary threat by far
again will be locally heavy rainfall and a low chance of flash
flooding given the very moist, tropical air mass in place.

&&

.LONG TERM...
(Thursday night through Monday)
Issued at 1120 PM CDT Mon May 25 2026

Most guidance shows the surface front pushing south of the area by
Thursday evening. Cloud cover should linger though behind the front
over the area. Not much appreciable cold air advection or drier air
shown right behind the front. This combination should keep overnight
lows on the warm side in the lower to mid 60s. This should also
provide a brief break from rainfall activity.

Most guidance moves the front northward around daybreak on Friday
into northwestern Alabama and possibly some of our southeastern
counties in AL. Forcing is not very strong, but does move back over
the area. Instability between 1000 and 1600 J/KG (some guidance a bit
more) does develop by the afternoon hours. Shear though is very weak
(~10 to 15 knots). PWATS remain high between 1.6 to 1.8 inches. So a
very saturated atmospheric column will not take much forcing to
produce heavy rainfall rates. A continue threat for a period of rain
and thunderstorms developing during the afternoon and early evening
is expected. A flooding risk will likely extend into Friday.

Much deeper and stronger forcing seems to develop in many models
Saturday overnight as the main upper level trough axis moves east
aloft. This could produce a concentration of heavier rainfall and
some storms more so over Georgia and maybe extending west into NE
Alabama. A risk for some flash flooding will likely continue on
Friday afternoon into Friday night.

Models diverge on how amplified the upper level trough axis is Friday
night into Saturday and into the weekend, which will have a big
impact on whether the front shifts south of the area or not.

Model converge a bit more on stronger forcing and shear developing
over the area on Monday. Shear is better with this system and
instability is not bad. There may be some strong to severe
thunderstorm threat with that system, but this is too far out in
the extended to have much confidence with it.

&&

.AVIATION...
(00Z TAFS)
Issued at 705 PM CDT Tue May 26 2026

VFR conditions have prevailed across the area as shower activity
has been less than anticipated for the time being. Believe the
majority of the rain will stay to our south and east through much
of the evening and overnight hours, but expect MVFR cigs to move
into the area during the late night/early morning period. Medium
to high rain chances will continue through tomorrow, where MVFR
conditions become more likely within any heavier showers. Winds
will gradually veer to the SW through the TAF period but should
remain light.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Flood Watch until 10 PM CDT this evening for ALZ006>010-016.

TN...None.
&&

$$

NEAR TERM...AMP
SHORT TERM....AMP
LONG TERM....KTW
AVIATION...25