656
FXUS64 KHUN 062354
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
554 PM CST Mon Jan 6 2025

...New AVIATION...

.NEAR TERM...
(Tonight)
Issued at 238 PM CST Mon Jan 6 2025

A Winter Weather Advisory remains in effect until 7 PM for our
northern Alabama and southern middle Tennessee counties. We have
seen some reports of icy conditions in portions of Cullman
counties into the Florence area and in southern middle
Tennessee/NE Alabama with light snowfall that has fallen and
stuck to the ground on grassy surfaces and melted/refrozen.
Expect temperatures to remain in the upper 20s to around 32
degrees through the remainder of the afternoon, as clouds remain
in place and light snowfall or flurries continue, mainly in NE AL
and southern middle Tennessee at this time. Earlier snowfall in
portions of NW Alabama have tapered off. Though more flurries
could occur their, not expecting much more accumulation there, but
slick conditions will not improve either in the evening hours
given cold temperatures forecast.

However, models hint at another round of light to briefly
moderate snow moving southeast from north central Tennessee into
southern middle Tennessee and NE Alabama this towards sunset into
the evening hours. This could produce another light dusting up to
0.4 inches in some locations in those areas. Some locations by
midnight in those locations could see up to 1 inch of total
snowfall accumulation over the last 24 hours. There is some
uncertainty with this scenario. So for now, the Winter Weather
Advisory only goes to 7 PM. However, this may need to be extended
if conditions warrant into the evening hours. Breezy conditions
continue with winds 15 to 20 gusting to around 35 mph at times.

Even drier and colder air will move into the area after midnight.
This should allow lows to drop into the upper teens to lower 20s.
The windy conditions will drive wind chill values into the lower
teens to around 20 degrees.

&&

.SHORT TERM...
(Tuesday through Thursday)
Issued at 238 PM CST Mon Jan 6 2025

Sunny skies are expected to return Tuesday afternoon. This should
help to warm things up some. However, with the re-enforcing shot
of cold air into the day, highs will be hard pressed to reach the
32 to 36 degree range mainly. Winds will remain northerly between
5 and 10 mph with gusts up to 20 mph at times. Wind chill values
will drop remain between 25 and 30 degrees through the day.

Winds will likely weaken a bit more, but remain 4 to 8 mph
Tuesday night. This will help keep lows a bit warmer than they
could be, but they still will drop into the upper teens to the
lower 20s. Wind chill values will drop into the mid teens to lower
20s. Wind Chill values of 15 to 20 degrees are expected as a
result.

Slightly warmer conditions are expected on Wednesday with a few
more upper 30s expected for highs. Lighter winds and drier air is
expected to advect into the area on Wednesday afternoon behind a
dry clipper system. With clear skies, lows should be able to drop
into the lower to mid teens primarily. Highs on Thursday warm up
a bit more into the upper 30s primarily, as an area of high
pressure slides east north of the area.

&&

.LONG TERM...
(Thursday night through Monday)
Issued at 238 PM CST Mon Jan 6 2025

Longer range models continue to suggest much below normal
temperatures to continue across the Southeast through the extended.

A long wave trough is expected to dive towards the four corners
states. A shortwave located on the western side of the trough may
help to amplify the trough and may even cut off into a 500 mb low
pressure from the main flow. As the cut off low moves gradually
eastward by early Thursday, it will rejoin the jet stream again and
re-amplify the trough. Vorticity should also increase as vorticity
from the upper-level low combines with vorticity from the upper-level
trough over the eastern Rockies. With the increased vorticity and
baroclinicity, surface cyclogensis can begin, with a low developing
in the western Gulf of Mexico. Divergence aloft, in the front right
entrance region of a developing jet streak should help to amplify
mass displacement and further increase development of the surface
low.

By Friday, cyclogenesis continues as the surface low begins to move
across the Northern Gulf Coast. With this, the big question becomes
exactly where does the surface low track. A northerly track into S.
AL/FL Panhandle or a southerly track into the FL Big Bend.

The exact track of the surface low will have impacts here locally
across the TN Valley. This is because a northerly track may allow for
the warm conveyer belt to extend further northward and allow for a
wintry mix rather than just snow (especially south of US 72). A
southerly track would allow for the warm conveyer belt to stay
further south and allow for freezing conditions to extend further
south (implying more snow). Models have trended towards a snow event
rather than an icy event event, especially in NW AL. However, it is
possible that as we get into the afternoon on Friday, some wintry
precipitation could mix in at spots near the freezing line with a
warm nose just above the boundary layer.

The timing for this would be starting very late Thursday (1/9) and
into Friday morning (1/10) across SW CWA counties and expanding NW
throughout the early morning hours on Friday. If there were to be any
wintry mix, the best chance would be in the afternoon. Lastly,
transitioning back into snow later in the day. Any wintry
precipitation should depart the area late Friday and into Saturday
morning, though confidence is lower than the system arrival.

In terms of snow accumulations, models have trended towards about a
1 inch average across the CWA, with possibly 1-2 inches in NW AL.
Some locally heavier amounts will be possible depending on where
heavier snow pockets may set up.

With any ice accumulations, this mainly would be greatest in
southern CWA counties, of possibly up to 0.1 inches, though
confidence is low at the moment.

As we get into Saturday, the upper-level pattern becomes more zonal
as the jet streak and surface low moves towards the mid-atlantic. GFS
has hinted at possibly some snow showers into the morning on
Saturday, but should be on the lighter side compered to Friday.
However, very cold conditions will remain through Sunday with highs
in the 30s and lows in the teens and 20s. Wind chill values even
lower than that.

Make sure to continue protecting the 4 P`s: People, Pets, Plants,
and Pipes through the weekend. Since ice will be possible, drivers
should prepare to exercise caution when on the roadways, especially
on Friday and Saturday.

&&

.AVIATION...
(00Z TAFS)
Issued at 554 PM CST Mon Jan 6 2025

MVFR conditions are expected for both HSV and MSL through about
early Tuesday afternoon. This is mainly due to lower ceilings
overnight as lower-level stratus remains across the area. Winds
should subside through tonight to about 10 kts by tomorrow morning
with possible gusts up to 20 kts. Clouds begin to clear the area in
the early afternoon, returning VFR conditions.


&&

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

$$

NEAR TERM...KTW
SHORT TERM....KTW
LONG TERM....Serre
AVIATION...Serre