549
FXUS64 KHUN 132346
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
546 PM CST Sat Dec 13 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 440 PM CST Sat Dec 13 2025

 - There is a 15-40% chance for light rain or drizzle tonight with
   less than 0.05 inches of total rainfall.

 - Sub freezing temperatures will move into the area towards
   daybreak on Sunday and continue through Monday morning.

 - A Cold Weather Advisory is in effect for Lincoln, Moore, and
   Franklin counties in TN from midnight tonight through 6PM
   Sunday. Another Cold Weather Advisory is in effect for all of
   north Alabama and southern middle Tennessee from 6PM on Sunday
   through 6PM on Monday.

&&

.NEAR TERM...
(Tonight)
Issued at 159 PM CST Sat Dec 13 2025

Sunny skies continue across northern Alabama and southern middle
Tennessee this afternoon. The insolation and weak warm air
advection in the boundary layer has allowed temperatures to climb
into the lower to mid 60s in most areas. The warmest temperatures
are in place south of the Tennessee River near Vinemont, AL and
Albertville, AL. In these locations temperatures have already
reached 66 and 68 degrees respectively.

Mostly cloudy conditions will push into the area very late this
afternoon (after 3 or 4 PM) from the south and the west. This
cloud cover will occur ahead of a weak surface low along the
arctic cold front that stretches from the southern Kentucky into
southwestern Arkansas at this time. This cloud cover pushes
southeast late this afternoon/early evening towards the Tennessee
Valley region. Some decent isentropic lift is seen in the
saturated cloud layer ahead of and slightly behind this front as
it moves further southeast this evening.

Overall, the saturated cloud layer is a bit deeper in the newest
models runs than yesterday`s runs. Not a lot of lift seen through
isentropic lift below 285K in this cloud layer, but near the top
of that layer (~295K), better lift is seen this afternoon into the
early evening hours. This lift will likely lead to evaporative
cooling very late in the afternoon, which will likely keep highs
from reaching the upper 60s in most areas, despite abundant
sunshine. Also, it looks like isolated to scattered rain showers
will develop in response to this lift. Not looking at heavy
rainfall, but scattered light rain showers are expected,
especially south of the Tennessee River. With abundant sunshine
much of the day, highs will likely climb into the mid 60s in many
locations south of the Tennessee River.

New runs continue to push this precipitation and the arctic air
behind the front quickly east towards the Tennessee Valley
tonight. However, the truly arctic air will likely lag behind the
frontal boundary and move into southern middle Tennessee and
northern Alabama towards daybreak. This should keep any wintry
precipitation out of the forecast, as the isentropic lift even at
295K moves east of the area between 10 PM and midnight tonight.

&&

.SHORT TERM...
(Sunday through Tuesday)
Issued at 1214 PM CST Sat Dec 13 2025

The bigger issue will be the wind chills, as a strong 925 mb jet
of 20 to 30 knots develops near and just behind the arctic front
towards daybreak on Sunday and remains in place through much of
the day on Sunday. Sustained winds of 10 to 15 mph with gusts
around 25 mph are expected due to the wind energy associated with
the 925 jet aloft. This will drive wind chill values to between 0
and 5 degrees in portions of our southern middle Tennessee
counties. Thus, the Cold Weather Advisory was extended back in
time for Lincoln, Moore, and Franklin counties in Tennessee from
midnight tonight through 6 PM on Sunday.

Not much relief is expected on Sunday as actual highs will be
hard pressed to climb above the 30 degree range, except maybe in
Cullman, Marshall, or Dekalb counties in AL. With the 925 mb jet
remaining over the area and only weakening to 20 to 25 knots later
in the afternoon, windy conditions will continue. Though wind
chill values will climb into the teens in the afternoon, it is a
brief respite. Temperatures will fall quickly with the loss of
daytime heating and continued cold air advection Sunday night.
Temperatures should drop into the 10 to 15 degree range in most
locations by the evening hours. Though winds will not be as strong
they still will be between 5 and 10 mph much of the night, with
some gusts in higher elevations of NE AL to between 15 and 20 mph
lingering through daybreak on Monday. This should drive wind chill
values to around 5 degrees across many areas of northern Alabama
and our southern middle Tennessee counties (A few locations such
as higher elevations of NE Alabama and southern middle Tennessee
could see a few wind chill values as low as 0 degrees). Thus,
keeping the Cold Weather Advisory in effect for all of our
northern Alabama and southern middle Tennessee counties from 6 PM
on Sunday through 6 AM on Monday morning.

Temperatures should warm into the low 40s Monday afternoon.
However, one more cold night is expected Monday night as lows drop
into the 20s. Luckily winds will be light, so winds chills will
not be much of a concern.

&&

.LONG TERM...
(Tuesday night through Saturday)
Issued at 159 PM CST Sat Dec 13 2025

This warming trend will continue through mid week as a result of
upper level ridging and subsequent sfc high pressure shifting over
the area. While the majority of the long term period remains dry,
rain chances return towards the middle or end of next week, as an
upper level shortwave develops over SE Texas and a weak clipper
system moves quickly southeast though the Tennessee Valley on
Wednesday/Wednesday night. How much moisture this clipper system
can draw north from the disturbance over SE Texas is in question
by guidance. A big spread concerning that aspect of the forecast.
Stayed on the lower end of NBM ensemble PoP (20-40%) for that
reason.

Either way, guidance does show a stronger cold front pushing east
Wednesday night into Thursday before exiting northern Alabama and
southern middle Tennessee Thursday night. We will continue to
monitor this system in future updates. The more widespread chances
for heavier rainfall remain primarily north of our area at this
time (where the LLJ is stronger) with this system. However, models
do show some surface based and elevated instability and just
enough shear in place for some isolated to scattered thunderstorms
to develop ahead of this front.

Dry weather returns to the forecast behind this front Saturday
into Sunday. A big temperature drop behind this front is not
expected, but it will be cooler during that period. with highs
dropping back into the 50s and lower 60s again.

&&

.AVIATION...
(00Z TAFS)
Issued at 546 PM CST Sat Dec 13 2025

Clouds are overspreading north Alabama and southern middle
Tennessee this evening and will bring not only a low chance
(15-30%) of light showers, but also lower CIGs. MVFR CIGs are
forecast at both terminals by 2-4Z this evening and will persist
through late tonight. Instances of IFR are possible, but
confidence in this occurring at the TAF sites is low. Any
precipitation is then expected to come to an end between 5-7Z,
with dry (and VERY cold) weather to follow. Clouds will also begin
to clear, with VFR conditions returning, around 12Z Sunday
morning. The other big concern for the forecast period will be
elevated winds, with sustained northerly winds between 10-15 knots
and gusts to 20-30 knots developing tonight and lasting through
much of the day on Sunday.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Cold Weather Advisory from 6 PM Sunday to 6 AM CST Monday for
     ALZ001>010-016.

TN...Cold Weather Advisory from midnight tonight to 6 AM CST Monday
     for TNZ076-096-097.

&&

$$

NEAR TERM...KTW
SHORT TERM....KTW
LONG TERM....KTW
AVIATION...26