052
FXUS64 KHUN 201142
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
542 AM CST Thu Nov 20 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 406 AM CST Thu Nov 20 2025

 - A Dense Fog Advisory is in effect through mid-morning, with
   shower and storm chances returning this afternoon into this
   evening. The best chances are primarily north of the Tennessee
   River.

 - Additional showers/storms are forecast Friday afternoon through
   the overnight hours with a low chance some could become strong.

 - Cloudy and mostly dry weekend (rain chances less than 20%) is
   forecast with the next system to monitor moving in on Tuesday.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 406 AM CST Thu Nov 20 2025

Visibilities over the past few hours have decreased to between a
quarter to 2 miles for many locations (as seen by surface
observations). Opted to issue a Dense Fog Advisory to account for
lowering visibilities over north Alabama just before midnight;
however, ended up expanding the Advisory not much longer after
that to include southern middle Tennessee as trends over these
areas became similar. This Advisory remains in effect through 9AM
this morning for all of north Alabama and southern middle
Tennessee. Please take caution on your morning commute - drive
slowly, leave extra room between you and the vehicle in front of
you, and use low-beam headlights!

The fog will lift and dissipate through mid-morning. Then, our
attention shifts to the afternoon, where medium to high (30-70%)
chances of showers and storms are forecast along and north of the
Tennessee River (especially over southern middle Tennessee). As
the previous shift mentioned, this is due to a surface boundary
forecast to be draped just south of the Alabama/Tennessee border,
creating a moisture gradient. While model guidance indicates that
there is ample shear, cloud cover likely will limit the amount of
instability that is realized this afternoon. CAPE values shown by
models are up to around to 300-500 J/kg this afternoon into this
evening. Regardless, this may be enough for some gusty winds to be
produced in any stronger storms that might develop. We`ll keep an
eye on this through the day, but severe weather is not
anticipated at this time.

Through the evening and into the overnight hours, shower/storm
chances gradually wane. However, low temperatures will continue to
be warm as elevated moisture persists. Temperatures are expected
to merely drop into the mid 50s to around 60 degrees tonight. The
other concern may be patchy fog; although, there are a couple of
caveats to this. Cloud cover as well as ever so slightly stronger
winds (compared to last night/early this morning) may keep much of
the fog at bay, except in river valleys and for locations next to
bodies of water. This will be monitored, but not currently
expecting widespread dense fog.

&&

.SHORT TERM...
(Friday through Saturday)
Issued at 914 PM CST Wed Nov 19 2025

A lull in rainfall is forecast to occur Friday morning before
medium rain chances return Friday afternoon into the evening as an
upper level trough shifts eastward over the area. There is
disagreement in the recent CAMs, with most of them keeping the
widespread rainfall both north and south of the area and only
allowing a few showers/storms to form through the TN Valley
(primarily in southern middle TN). Any showers/storms that do form
have a very low chance of becoming strong as model soundings show
a cap in place- limiting instability. We will continue to monitor
this system through the end of the work week as new hi-res
guidance is introduced. Showers will likely come to a gradual end
on Saturday morning, leaving a cloudy and mostly dry weekend in
their wake.

&&

.LONG TERM...
(Saturday night through Wednesday)
Issued at 914 PM CST Wed Nov 19 2025

The long term forecast will be focused on the passage of a surface
cyclone and associated cold front on Tuesday. Through the weekend
and into the beginning of the work week, A mid level cut off low
will deepen and drop along the pacific coast before progressing
northeast through the CONUS. Ahead of its arrival, we will find
ourself between troughing to our SE and ridging to our north.
Unfortunately the two competing regimes will lead to little
changes in airmass in place meaning more days of partly to mostly
overcast conditions, low (10-30%) rain chances, highs in the 60s
and 70s and muggy dewpoints in the 50s and 60s through the start
of the work week.

Mid range models are in good agreement in bringing the front into the
TN Valley on Tuesday however still lack agreement regarding the finer
thermodynamic details and the evolution of surface cyclone once
it reaches the eastern CONUS. A few trends are becoming apparent
in the models that will make this system worth watching for severe
weather potential. First, we will maintain a very moist boundary
layer leading up to the passage of the front. Additionally, the
synoptic scale of the front will favor the presence of sufficient
bulk shear. With these two parameters present, it won`t take much
instability or forcing to support some stronger storms within the
larger area of rain. For now, stuck with blended guidance bringing
in 50-60% rain and thunder chances with the front on Tuesday
morning with 20-30% rain chances lingering behind the front
through Wednesday.

&&

.AVIATION...
(12Z TAFS)
Issued at 542 AM CST Thu Nov 20 2025

Dense fog has been reported at both terminals overnight, along
with very low CIGs. Overall, these conditions are expected to
persist for the next couple of hours before beginning to improve.
The fog should lift and dissipate through mid-morning and CIGs
will gradually improve to at least MVFR through late morning and
into the early afternoon. By this time, low to medium chances
(30-60%) of showers and storms exist at both terminals. This
activity could bring lowered VIS and CIGs in the heavier/stronger
storms in addition to some gusty winds. However, by the evening,
the shower and storm activity looks to shift north/northeast and
chances decrease for the terminals through late evening. VFR
conditions are then anticipated this evening and for much of the
overnight. Outside of any storms, winds will be calm early this
morning but become light and variable through mid-morning. Winds
will then become southwesterly and increase, hovering around 5
knots through the afternoon before becoming light and variable
once again this evening.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Dense Fog Advisory until 9 AM CST this morning for ALZ001>010-
     016.

TN...Dense Fog Advisory until 9 AM CST this morning for TNZ076-096-
     097.

&&

$$

NEAR TERM...26
SHORT TERM....HC
LONG TERM....RAD
AVIATION...26