479
FXUS64 KHUN 182314
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
514 PM CST Tue Nov 18 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 1127 AM CST Tue Nov 18 2025

 - A broken band of showers and thunderstorms will impact the
   region from late this evening through early Wednesday morning,
   with a conditional risk for a few strong storms (mainly across
   northwest AL/southern TN).

 - After a brief intrusion of drier air Wednesday night, a
   warm/humid airmass will remain in place through the first half
   of the weekend.

 - There is a high (60-80%) chance for rain and some thunderstorms
   on Friday and Friday night.

&&

.NEAR TERM...
(Rest of Today and Tonight)
Issued at 138 PM CST Tue Nov 18 2025

There have been no changes to forecast reasoning in the near term
since the update earlier this morning, with temperatures on track
to reach forecasted highs in the l-m 70s as gusty SSW winds
advect a moist airmass northeastward across the region. Late this
afternoon (22-24Z) we expect to see a band of convection evolve
within a subtle streamline confluence axis extending from western
TN into south-central KY. Although this initial band may tend to
weaken before reaching our CWFA early this evening, a second and
more prominent zone of showers and thunderstorms it predicted to
evolve to its northwest over the course of the evening, and this
is the activity that we will need to monitor for strong wind gusts
and potential development of weak low-level mesocyclones (in
spite of weak CAPE and the low-topped nature of convective
updrafts). It still appears as if this risk will be greatest as
showers and storms enter the northwest portion of the CWFA between
4-6Z. Regardless of precipitation coverage, it will be a
cloudy/warm and humid night, with lows in the u50s-l60s.

Previous Discussion:
A weakening mid-level shortwave trough will progress east-
southeastward from western IA into northern portions of IL/IN over
the course of the day, as it enters a region of increasingly
confluent flow between a broad scale trough over eastern Canada
and a subtropical ridge expanding northward across the
southeastern Gulf/northwestern Caribbean Sea. At the surface, a
decaying area of low pressure will shift southeastward from
eastern KS/western MO into the Mid-MS Valley by 0Z, with
strengthening SSW flow around the western periphery of an
anticyclone to our east allowing the eastern edge of a maritime
tropical airmass (featuring dewpoints in the u50s-l60s) to spread
into the region this afternoon. Present indications are that
widespread rain and elevated convection related to warm/moist
advection near and south of the cyclones effective warm front (but
atop a lingering dry airmass in the boundary layer) will be
confined to points north of the TN-KY border, and although a few
showers may develop over the course of the afternoon as dewpoints
rise across western/middle TN, we will keep our forecast dry at
this time. Regardless of the recent increase in mid-level stratus,
sufficient insolation should occur for highs to reach the l-m
70s, especially with a SSW wind of 10-15 MPH (gusting to 20-25
MPH).

The degenerating 500-mb trough will accelerate east-
southeastward into the Mid-Atlantic Coast overnight, with the
increasingly ill-defined area of low pressure expected to open
into a trough and shift further southeastward into eastern
portions of TN/KY by 12Z. However, low-level convergence should
remain sufficient for the development of surface-based convection
late this afternoon across southeastern MO/southern IL/western KY
that may expand into a broken band of showers/thunderstorms from
eastern AR into eastern KY over the course of the evening
(potentially beginning to impact the northwestern portion of the
CWFA by 4-6Z before spreading southeastward during the early
morning hours Wednesday). Although the intensity of convection
will be on a weakening trend as it tracks across our region (due
to both an inversion in the 5-10 kft layer and nocturnally
diminishing CAPE), WNW flow aloft of 40-50 knots will support
storm organization (should any deeper updrafts evolve) and 850-mb
westerly flow of 25-35 knots could lead to weak low-level rotation
in this scenario. Thus, there is at least a very low risk for a
few stronger cells (especially as storms initially enter the
CWFA). Otherwise, we anticipate a cloudy and mild night, with lows
in the u50s-l60s.

&&

.SHORT TERM...
(Wednesday through Thursday night)
Issued at 1127 AM CST Tue Nov 18 2025

Latest short range model consensus suggests that a subtropical
ridge to our south will amplify northward across the Gulf Coast on
Wednesday, in response to a slow-moving southern stream trough
across the southwestern CONUS/northwestern Mexico. In the wake of
nocturnal showers and thunderstorms (which should be exiting the
southeastern portion of the forecast area around 12Z Wednesday), a
moist airmass (with dewpoints in the l-m 60s) will remain in
place across the region, with abundant low stratus clouds
throughout the day likely to prevent redevelopment of convection
tomorrow afternoon even as afternoon temps rise into the m-u 70s.

A remnant low-level confluence axis (initially across TN) may
drift southward into the local area Wednesday night, providing at
least some influence from a surface high centered across New
England. Should this occur, light NE winds may briefly advect
dewpoints in the m-u 50s into the region, providing for cooler
overnight lows Thursday morning. Current thinking is that the
boundary will lift northward once again late Thursday morning, as
the southern stream trough (mentioned above) begins to accelerate
northeastward, inducing surface pressure falls across southwest
TX. Throughout the day, an axis of rain and embedded convection
will likely setup in the vicinity of the warm front from the
Ozarks into central KY/middle TN, but with this axis likely to be
displaced to our north, we will only mention a 20-30% POP across
our northern zones Thursday afternoon/evening. Additional showers
may develop early Friday morning from the Lower MS Valley into
northern MS as the southwesterly low-level jet begins to
strengthen once again, but this should largely remain to our west
through 12Z Friday. Highs will remain in the m-u 70s Thursday
afternoon, with lows rising back into the u50s-l60s Friday
morning.

&&

.LONG TERM...
(Friday through Tuesday)
Issued at 926 PM CST Mon Nov 17 2025

Our main feature in the long term will be the passage of an upper
low and associated surface cold front on Friday. While it is
still a little too early to nail down specifics, a few trends are
becoming apparent. Boundary moisture looks to be plentiful on
Friday with at least some instability present. This is favorable
for some stronger storms with the passage of the front. However,
the weakening low calls into question how much forcing the front
will maintain by the time it reaches our area. Without any
significant forcing, strong to severe storms will be less likely.
The front looks to pass late Friday evening into overnight,
potentially limiting the amount of instability present. We will
keep an eye on forecast details for this feature as it draws
closer.

Weak ridging will build in behind the front inducing NW flow.
This will drop our temps to the mid to high 60s during the day and
40s overnight. Unfortunately enough moisture looks to linger
behind the front to keep partly cloudy skies and low (10-30%) rain
chances each day through the weekend and into the start of next
week.

&&

.AVIATION...
(00Z TAFS)
Issued at 514 PM CST Tue Nov 18 2025

While VFR conditions continue for now, they will be relatively
short-lived as low-medium chances for showers move in overnight
with subsequent lowered ceilings. By Wednesday morning, MVFR to
IFR conditions are forecast throughout the area along with light
NW winds. VFR conditions should return by Wednesday afternoon as
cloud cover becomes more scattered.

&&

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

$$

NEAR TERM...70
SHORT TERM....70
LONG TERM....RAD
AVIATION...HC