Somerville, Alabama Weather Forecast Discussion

693
FXUS64 KHUN 230005
AFDHUN
Area Forecast Discussion
National Weather Service Huntsville AL
705 PM CDT Mon Sep 22 2025
...New AVIATION...
.NEAR TERM...
(This Afternoon and Tonight)
Issued at 110 PM CDT Mon Sep 22 2025
As expected, thunderstorms have developed rapidly during the past
couple of hours across southern middle TN through northwest AL. A
couple of storms have shown transient TBSS with small hail. Expect
thunderstorms to persist with SBCAPE of 2000-2500 j/kg and ample
daytime heating. Not much change in thinking from earlier update
for tonight with a low chance this evening and again late tonight
when the next upper level impulse arrives.
Previous Discussion...
Issued at 1010 AM CDT Mon Sep 22 2025
Visible imagery shows that widespread mostly mid level clouds are
beginning to thin out in some areas, allowing for more prolific
sunshine and solar heating. With dew points in the upper 60s to
around 70, scattered bands of showers and thunderstorms should
develop through the day. With a weakly sheared environment and
modest lapse rates, would not expect an organized severe threat
today. But a few stronger storms still seem plausible. A decline
in activity after sunset should occur as well although an MCV from
the MCS over AR may tend to keep some activity around through the
night, especially to our north in TN and KY. Expect high
temperatures in the middle 80s to around 90 this afternoon (a few
degrees cooler atop the higher elevations). High dew points in the
60s will keep overnight lows in the middle to upper 60s.
&&
.SHORT TERM...
(Tuesday through Wednesday night)
Issued at 1010 AM CDT Mon Sep 22 2025
Another MCV will advance from the Plains into the mid South and
OH valley on Tuesday as moist and warm southerly flow persists in
low levels. The more widespread convective activity will be to our
north and closer to low level convergence at the nose of the low
level jet of 20-30kt. We will maintain low chances of
thunderstorms through Tuesday into Tuesday night, with a low
threat of gusty to damaging winds. High temperatures will once
again reach the middle 80s to around 90 in valley areas. Chances
of more organized thunderstorms and some severe weather increase
Wednesday afternoon into Wednesday night as an upper trough drops
southeast into the Great Lakes through the southern PLains. This
will enhance mid level winds into the 30-40kt range, increasing
the bulk shear profile. The biggest question mark is the amount of
cloud cover and instability that can develop ahead of this
system. Several of the models indicate several ongoing convective
clusters to our west that may move in during the daylight hours
which may inhibit stronger daytime heating. In either case, medium
to high chances of showers and thunderstorms will remain in the
forecast Wednesday through Wednesday night.
&&
.LONG TERM...
(Thursday through Sunday)
Issued at 1051 PM CDT Sun Sep 21 2025
Global models suggest that the coverage of rain and thunderstorms
will remain rather high across the TN Valley on Thursday, with
redevelopment of another band of convection possible during the
afternoon/evening as a weak cold front slides southeastward into
the forecast area. Although mid-level winds will remain in the
40-50 knot range and conducive for organized thunderstorms,
impacts from previous convection make instability highly
uncertain. Regardless, locally heavy rainfall will remain a
possibility given precipitable water values in the 1.8-1.9" range.
Present indications are that a drier and slightly cooler
continental airmass will finally work its way southeastward into
the region Thursday night/Friday morning, and although some low-
clouds and warp-around showers will be possible on Friday, the
remainder of the period appears to be dry at this point. Highs
will be in the u70s-l80s, with lows in the u50s-l60s.
&&
.AVIATION...
(00Z TAFS)
Issued at 705 PM CDT Mon Sep 22 2025
VFR will be the prevailing condition at the HSV/MSL terminals
overnight, featuring an overcast layer of high-lvl convective
debris clouds and lgt/vrbl winds. Although latest radar data
indicates that the risk for a few lgt SHRA (remnants of afternoon
convection) may continue thru 4Z, we will need to watch for
potential redevelopment of additional storm clusters to our
northwest, which may have a tendency to backbuild into northern
portions of the forecast area between 4-10Z based on a favorable
orientation of the low-level jet. For this reason, we have only
included a TEMPO group for the first four hours of the TAF period,
but amendments to include additional convective impacts early
Tuesday morning may be warranted. Otherwise, patchy mist and fog
may develop btwn 9-13Z (especially where wetting rains occurred
earlier today), but given the anticipated coverage of high-lvl
clouds we will not mention vsby reductions attm. A sct Cu field
will redevelop by 23/15Z, with the greatest coverage of
showers/storms expected to be focused to our north (across Middle
TN) tomorrow aftn.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&
$$
NEAR TERM...17
SHORT TERM...17
LONG TERM...70/DD
AVIATION...70/DD

NWS HUN Office Area Forecast Discussion