Lester, Alabama Weather Forecast Discussion

467
FXUS64 KHUN 051837
AFDHUN
Area Forecast Discussion
National Weather Service Huntsville AL
137 PM CDT Fri Sep 5 2025
...New NEAR TERM...
.NEAR TERM...
(Tonight)
Issued at 137 PM CDT Fri Sep 5 2025
The forecast remains on track for this afternoon, evening, and
overnight, with a low threat for severe thunderstorms, with a main
window from 6 PM to 2 AM CDT. A few isolated showers have
developed in central Alabama along a weak convergence boundary,
but don`t think this activity will develop any further to the
north in our area. Given the current satellite presentation, think
that our prospects for any convection before 5-6 PM are pretty
low. We will continue to watch convection develop along the
frontal boundary to our northwest and would expect this to get
going with the interaction of the boundary with an ejecting
shortwave by the early evening hours. More on this in the
previous discussion included below.
Previous Discussion:
An active period of weather is on tap for the Tennessee Valley
late this afternoon and evening into portions of tonight as a cold
front slowly approaches the region from the northwest. Ahead of
the front, deeper southwesterly winds and ample sunshine should
warm temperatures into the low to mid 90s in most locations.
Despite these very warm temperatures, a weak capping inversion
should remain in place -- preventing any convection from forming
until the very late afternoon/evening. The forcing mechanism(s)
that will eventually get things going will be the cold front
itself as it slides into far northwest AL into portions of middle
TN and eastern KY and a shortwave trough that will interact with
this feature during the 00-06z timeframe this evening, providing
around 30-40 kts of effective shear. Coupled with around 1500-2000
J/kg of MLCAPE, this environment will support organized multicell
clusters and mini supercells capable of gusty/damaging wind gusts
up to 50-70 MPH. Hodographs really don`t favor even a lower-end
tornado threat, especially coupled with the higher LCLs. However,
right-movers and any surges/cell mergers will as always need to be
monitored closely for rotation.
The main forecast question continues to deal with timing as much
of this convection will be tied to the arrival of the
aforementioned shortwave. Based on the latest guidance and
observational trends, think it will be tough to get things going
anywhere in our area before 5 to 6 PM, with the main window likely
being 6 PM to 2 AM before instability really begins to wane.
Locations across northwest AL and southern middle TN will be more
favored for some strong/severe convection initially in the earlier
part of the window -- with central/eastern portions of the area
likely dry until the late evening into tonight. After the initial
wave of showers and storms, a break may occur late tonight into
early Saturday morning hours -- before another round of showers
and elevated storms occurs later on Saturday morning. More on this
in the section below.
&&
.SHORT TERM...
(Saturday through Monday)
Issued at 1055 AM CDT Fri Sep 5 2025
The cold front will finally make it into and through the area
Saturday morning, with more widespread shower/elevated
thunderstorm activity expected during the morning to early
afternoon as another shortwave swings through the region.
Eventually, rainfall will dissipate by the early/mid afternoon and
a cooler and drier air mass will settle in as evidenced by highs
in the upper 70s to lower 80s. We`ll clear out Saturday night,
with patchy fog likely given the recent rainfall. Otherwise a good
setup for radiational cooling with lows in the 50s overnight. High
pressure will build in from the north and west Sunday and Monday,
with dry conditions forecast both days -- with plenty of sunshine
to enjoy. Highs in the upper 70s to lower 80s will be common, with
lows in the 50s.
&&
.LONG TERM...
(Monday through Thursday)
Issued at 923 PM CDT Thu Sep 4 2025
Zonal flow aloft to start the long term looks to turn into weak
ridging by Tuesday. Although an upper shortwave swings over the Great
Lakes and Ohio Valley on Wednesday, mainly zonal flow will return to
the Tennessee Valley as the base of that trough traverses the
region. Northwest flow is then anticipated by Thursday as a stout
upper ridge builds over the central CONUS. Meanwhile, surface high
pressure will build over the Midwest and the Ohio and Tennessee
Valleys early next week. This feature is expected to gradually push
eastward through midweek due to systems developing over the western
CONUS and central Canada.
For sensible weather for our local area, the influence of surface
high pressure is expected to keep mainly dry conditions through the
majority of the long term period. Although, temperatures are forecast
to gradually increase through the week. Highs begin in the mid 70s
to lower 80s on Monday, then by Thursday reach the mid 80s to around
90 degrees. Lows follow a similar pattern, increasing from the lower
to mid 50s early in the week into the mid to upper 50s by later in
the week.
&&
.AVIATION...
(18Z TAFS)
Issued at 1232 PM CDT Fri Sep 5 2025
VFR conditions will continue for much of the afternoon and into
the early part of the evening hours. A cold front will help to
generate TSRA/SHRA this evening and have included a TEMPO to
highlight the potential for MVFR conditions from reduced
visibilities and ceilings. AWWs and amendments may be needed
during this 00-06z timeframe. Thereafter, MVFR conditions will
prevail due to lower ceilings around 2.5 kft and another rounds
of -SHRA possible during the morning hours on Saturday.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&
$$
NEAR TERM...AMP.24
SHORT TERM....AMP
LONG TERM....26
AVIATION...AMP

NWS HUN Office Area Forecast Discussion