743
FXUS64 KHUN 181143
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
543 AM CST Thu Dec 18 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 345 AM CST Thu Dec 18 2025

-  Medium to high chances of showers through this evening, along
   with low chances of thunderstorms late this afternoon/early
   this evening.

 - Much colder Friday into Friday night with lows reaching or
   dipping below freezing.

 - A gradual warming trend then follows this weekend into next
   week with low chances of showers.

&&

.NEAR TERM...
(Today)
Issued at 345 AM CST Thu Dec 18 2025

Light showers have developed over the Southeast over the past
several hours. Activity is expected to continue to ramp up through
early this morning as a surface cold front approaches the region
from the west, with low to medium chances (30-60%) by about 6AM
and medium to high chances (50-80%) by roughly 9AM. High chances
of showers will then persist through the early afternoon. Not
expecting any thunderstorm development with this morning into
early afternoon activity. Then, a line of showers and storms are
shown by Hi-Res guidance to form along a pre-frontal trough late
this afternoon. This main line will then progress from west to
east over north Alabama and southern middle Tennessee, with a weak
line of showers and perhaps a storm or two following just behind
it (along the cold front).

What we are watching will be how much instability (energy for
storms) is realized through the day for the main line of showers
and storms later this afternoon. Limiting factors consist of cloud
cover and continued rain chances through the day. If there is
enough break in the shower activity and cloud cover, instability
could increase. Hi-Res guidance indicates that up to around 500
J/kg of MUCAPE may develop later this afternoon into the evening
ahead of the cold front that the aforementioned line of storms
could tap into. This, along with 55-60 knots of bulk shear, would
give storms plenty to work with to become strong to severe.
Damaging winds are the main threat with any strong storms that can
develop; however, confidence in strong/severe storms being able
to develop is low at this point due to the limiting factors
mentioned above. Stay tuned for updates today and stay weather
aware!

&&

.SHORT TERM...
(Tonight through Saturday Night)
Issued at 904 PM CST Wed Dec 17 2025

The cold front will sweep southeast of the area before Midnight
with strong cold air advection and blustery northwest winds
developing. Temperatures before daybreak should dip into the lower
30s, and only recover into the middle to upper 40s on Friday
(lower 40s atop the higher Cumberland Plateau). As high pressure
shifts east through the area Friday night, winds will drop and
temperatures should bottom out in the upper 20s east to 30-32
central and west. Westerly 5h flow will become established by
Saturday with moderate warm air advection developing as a thermal
ridge shifts east ahead of another cold front dropping southeast
into the Great Lakes through the lower OH Valley into Texas.
Afternoon highs on Saturday should reach the upper 50s to around
60. The cold front will bring low chances of light showers
Saturday night.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 904 PM CST Wed Dec 17 2025

On Sunday, a trough up in the Great Lakes region will push a cold
front into the Southeast. This will spark off a few showers (20%)
and the cooler northerly flow will keep daytime highs in the 50s.
Overnight lows will remain above freezing. The front will try to lift
back northward on Monday, providing another low chance (10-20%) of
showers across the TN Valley. Sfc high pressure in the OH Valley
will slide over to the Mid Atlantic coast by Tuesday, providing not
only dry conditions into mid week, but warmer temps too. We will
reach the lower 60s on Tuesday, and wait for this...reach the low to
mid 60s on Christmas Eve/Wednesday!

&&

.AVIATION...
(12Z TAFS)
Issued at 542 AM CST Thu Dec 18 2025

VFR conditions were observed at issuance; however, this will
quickly worsen through the morning hours as showers overspread
north Alabama. By late morning/early afternoon, IFR CIGs are
forecast at both terminals which will persist through early this
evening. High chances of showers will also continue for much of
the day, with a low chance of storms forecast later this
afternoon. A few of these may become strong and produce gusty to
damaging winds. Lower VIS is likely in the heavier showers as
well. As the line of showers and storms progresses east later this
evening, skies will gradually clear and VFR conditions will
return by midnight. Another concern today will be periods of LLWS.
For MSL, the first main bout of LLWS will be this morning around
14Z (southerly at around 40 knots). This will wane a bit for the
afternoon, but by this evening (~3-4Z) LLWS will be a concern at
both terminals (northwesterly at 40 knots). This is then expected
to gradually subside through midnight. Otherwise, expect a breezy
day with winds shifting from being out the south to being from the
northwest. Sustained winds will hover between 10-15 knots mostly
and gusts to between 15-25 knots are anticipated as well.


&&

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

$$

NEAR TERM...26
SHORT TERM....17
LONG TERM....JMS
AVIATION...26