328
FXUS64 KHUN 061149
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
549 AM CST Sat Dec 6 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 1105 PM CST Fri Dec 5 2025

 - Some patchy fog towards daybreak. Very brief patchy freezing
   fog possible in portions of southern middle Tennessee. Due to
   it expected patchy and brief nature, no significant impacts
   are expected.

 - Periods of light rain have a low-medium chance (20-40%) of
   occurring late Sunday afternoon through Monday morning.

 - Colder again Monday/Monday night with sub-freezing lows. Then
   warming again.

&&

.NEAR TERM...
(Today)
Issued at 414 AM CST Sat Dec 6 2025

In the mid/upper-levels, a highly sheared trough (initially
extending from the western Great Lakes to the central High Plains)
will progress quickly southeastward today within the flow between
a cold core vortex across southern portions of Hudson Bay and a
flat subtropical ridge centered east of the Bahamas. Strengthening
deep-layer ascent downstream from this feature has recently
resulted in the development of a few pockets of light rain well to
the north of a more dominant axis of precipitation in the
vicinity of a lengthy surface trough extending from the northwest
Gulf Coast into the southeastern Atlantic Coast. Based on the
northeastward movement of the light rain, we will include a very
low (10-20% POP) across our southeastern forecast zones through
15Z. Across the remainder of the forecast area, a layer of very
low stratus clouds exists, with light westerly flow (to the east
of a surface high across northern MS) keeping the boundary layer
sufficiently mixed to prohibit development of mist/fog.

The axis of the previously mentioned 500-mb trough is predicted
to cross the region later this morning or early this afternoon,
resulting in veering flow aloft and weak subsidence that should
contribute to rapid drying of the mid/upper tropospheric column.
However, this may not be sufficient to erode the layer of low
stratus clouds in the (especially given a relaxed pressure
gradient and light winds). Should this occur, currently advertised
max temperatures in the u40s-l50s may be 5 degrees or so too
warm, and we will nudge these down a bit to reflect this potential
scenario.

&&

.SHORT TERM...
(Saturday night through Monday)
Issued at 1105 PM CST Fri Dec 5 2025

Zonal to slightly SW flow aloft will be the rule of thumb Saturday
night into Sunday, as a weak longwave trough axis pushes from the
Central Plains into the Missouri Valley region. A frontal boundary
near the surface develops with it and merges with a weak area of
low pressure over the western Gulf coastal area. This surface low
helps to advect enough moisture northward ahead of this front to
allow for some precipitation to move into parts of Mississippi
Sunday morning and afternoon. Not sure if the atmosphere will be
moist enough for precipitation to reach the ground in NW Alabama
until late in the afternoon hours at the earliest if not after 6
PM CST. Took our 20 pop during the morning/early afternoon hours
the NBM ensemble was putting in for now. Kept a 20 pop in after 4
PM CST, with higher pop between 30 and 60 percent Sunday night.
Still looks like all rain with no thunderstorm activity.

The models still move the longwave trough axis ENE pretty quickly
Sunday night. Most guidance has the precipitation east or
northeast of the area by 12Z on Monday. This should keep any
wintry precipitation out of the forecast, but may need to watch
for flurries in southern middle Tennessee around and just after
daybreak. For now, left them out of the forecast since even
flurries would have little impact.

Much drier and colder again on Monday with some cloud cover
lingering into the early afternoon hours east of the I-65
corridor. Strong cold air advection should keep highs in the upper
30s to lower 40s, despite some afternoon sunshine.

&&

.LONG TERM...
(Monday night through Friday)
Issued at 1105 PM CST Fri Dec 5 2025

Back to sub-freezing lows again Monday night with clear skies and
high pressure building in. Lows in the mid 20s are expected. This
intrusion of colder air should be brief, as warm air advection
ahead of another front moving through the western Great Lakes
early next week keeps things on the warmer side. Highs in the
lower 50s should warm into the 55 to 60 degree range on Wednesday
with lows warming as well into the lower to mid 30s.

This front seems to have a hard time pushing into the southeast
and hangs up over eastern Texas into the Ohio Valley. However, a
weak pre-frontal trough axis looks to be close enough to produce a
few showers over the area Wednesday night into Thursday.

This weak pre-frontal trough axis may focus a bit more moisture
and forcing over the area Thursday afternoon into Thursday night,
before pushing east of the area. This should pull the precipitation
east with it as colder and drier air moves into the area. Highs
look to drop back down into the upper 30s to lower 40s again on
Saturday.

&&

.AVIATION...
(12Z TAFS)
Issued at 549 AM CST Sat Dec 6 2025

IFR-level stratus continues to blanket the entire forecast area
this morning, but very low chances for light rain will remain well
south of the terminals and a light westerly flow has thus far
inhibited development of BR/FG. There remains a considerable
amount of uncertainty regarding when the stratus layer will
eventually begin to mix out (if it does so at all), but at this
point we have optimistically indicated a temporary return to VFR
conditions this evening. However, with minor low-level moisture
advection expected to begin ahead of a secondary cold front, there
is some concern that low stratus (and perhaps some mist/drizzle)
may begin to redevelop prior to 12Z Sunday, with either no (or
only a brief) opportunity for clearing this evening. Sfc winds
will remain light for the duration of the TAF period, with winds
shifting to SSE by late mid/late aftn.

&&

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

&&

$$

NEAR TERM...70/DD
SHORT TERM...KTW
LONG TERM...KTW
AVIATION...70/DD