525
FXUS64 KHUN 042046
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
246 PM CST Thu Dec 4 2025

...New NEAR TERM...

.KEY MESSAGES...
Updated at 1014 AM CST Thu Dec 4 2025

 - Periods of rain start this afternoon and continue through late
   tonight with rainfall amounts up to 0.25-0.50 inches.

 - Fog development tonight into Friday morning and again Saturday
   morning may cause travel delays.

&&

.NEAR TERM...
(Tonight)
Issued at 246 PM CST Thu Dec 4 2025

Large swath of stratiform rain is right on our doorstep at the
MS/AL border spreading northeastward into southern middle
Tennessee. This area of rainfall will continue to shift eastward
over the next few hours, with all of north Alabama and southern
middle Tennessee expected to see some rainfall by tonight.
Rainfall amounts will most likely be around 0.25 inches areawide
and flooding issues are not a concern. High-end scenario rainfall
totals where more moderate rainfall rates set up this evening
could see up to 0.5 inches. Embedded lightning activity is not
expected as no instability is present. Rain exits from west to
east overnight with everyone in the TN Valley dry by sunrise.
Unfortunately, that does not mean clear skies by sunrise as
overcast, low clouds hang on into Friday. With light winds and the
ground sufficiently saturated, dense fog development will become
a concern going into the morning tomorrow, impacting the morning
commute. Temps should remain above freezing so freezing fog
causing slick surfaces is not the main concern so much as just the
sudden visibility reductions on area roadways.

&&

.SHORT TERM...
(Friday through Saturday)
Issued at 1014 AM CST Thu Dec 4 2025

Any fog that develops overnight behind the areas of rain will have
the potential to linger as late as noon in sheltered valleys.
Early morning commuters should allocate extra time just in case
the fog becomes dense. A dense fog advisory is not expected at
this time, but subsequent shifts will continue to monitor the
potential.

Weak high pressure at the surface settles into the Ohio River
Valley, so limited subsidence will keep skies overcast throughout
Friday. As a result, high temperatures will peak in the upper 40s,
similar to today. Moisture will remain trapped underneath the
overcast skies and not wicked away because of light winds. As a
result, fog remains a concern for Friday night into Saturday
morning. Drier air in the mid levels moves in late Saturday,
allowing skies to finally clear heading into Saturday night.

&&

.LONG TERM...
(Saturday night through Tuesday)
Issued at 1113 PM CST Tue Dec 2 2025

Some clearing Saturday night, but guidance shows mostly cloudy
conditions returning around midnight and continuing through the
overnight hours. Lows in the 35 to 40 degree range look
reasonable.

The main feature to watch through the long term forecast will be
the passage of a 500 MB trough through the eastern CONUS. Through
the weekend, the trough will amplify and move from the Plains into
the eastern CONUS. In association a surface low pressure system
looks to pass through the area from Sunday and Sunday night.

Deterministic models maintain high uncertainty regarding if any
precip will be present with the frontal passage. As such, stuck
with blended guidance that reflects the low chances of rain (~20%)
from Sunday night. If we do receive precip, especially near
daybreak Monday morning, we will have to keep an eye on temps as
they will likely near or just below freezing which could produce
brief and hopefully non-impactful wintry precip. We have very low
confidence in this however, just an interesting (non-impactful)
tidbit to keep an eye on.

Through the beginning of the work week, zonal flow aloft paired with
high pressure influence will promote non impactful weather. Temps
will have the opportunity to warm slightly with highs in the 40s and
50s. The forecast becomes slightly more uncertain from Wednesday
forward as models struggle to resolve our next system.

&&

.AVIATION...
(18Z TAFS)
Issued at 1117 AM CST Thu Dec 4 2025

Main impact for aviation today will be associated with rain moving
in from the southwest this afternoon. Ceilings will drop heading
into the evening down to IFR. With more persistent rain areas,
could see vsby lower to 3 SM. Rain tapers off early Friday morning
but low clouds and fog will remain. While flight categories were
only lowered to IFR, there is a low chance (20-30%) that LIFR cigs
linger until 12-15Z. Conditions gradually improve heading into
tomorrow afternoon and should return to VFR just after this TAF
period.

&&

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

$$

NEAR TERM...KG
SHORT TERM....30
LONG TERM....RAD
AVIATION...30