108
FXUS64 KHUN 232351
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
551 PM CST Sat Nov 23 2024

...New AVIATION...

.NEAR TERM...
(Tonight)
Issued at 215 PM CST Sat Nov 23 2024

High pressure continues to reign over the southeastern US and will
be paired with calm winds and clear skies tonight, leading to a
high chance of frost formation across the Tennessee Valley as
temperatures drop into the low 30s. A Frost Advisory has been
issued for all of northern Alabama beginning at 3 AM Sunday and
continuing through 8 AM to account for this. There are a few
locations with low-medium chances of hitting freezing
temperatures, however, this is not widespread enough to warrant a
Freeze Warning at this time. If the next update trends colder,
one may be issued.

&&

.SHORT TERM...
(Sunday through Tuesday)
Issued at 215 PM CST Sat Nov 23 2024

Another dry day is in store for us Sunday with high pressure
continuing to influence the area. Highs are forecast to warm
Sunday into Monday to reach the mid 60s to low 70s with the
assistance of southerly flow as the sfc high continues moving
eastward. Overnight lows during this time are forecast to be too
warm for frost concerns, remaining in the 40s to 50s. Monday into
Tuesday, rain chances return as a cold front moves in from the
west. The highest rain chances are forecast to be Monday evening
with medium to high chances (50-80%) throughout the TN Valley.
Extremely low instability and lapse rates will not support a
severe threat nor any thunderstorm development at this time. This
is forecast to taper off by Tuesday morning and dry weather will
return for the time being, however, increased rain chances return
mid week ahead of Thanksgiving Day. More on that in the long term
discussion below.

&&

.LONG TERM...
(Tuesday through Friday)
Issued at 125 AM CST Sat Nov 23 2024

By Tuesday morning, we will be in the wake of a cold front as the
broad upper trough axis shifts east of the area and the upper
level flow becomes more zonal to slightly northwest. High pressure
will settle into the region Tuesday, keeping the forecast dry
with highs in the 50s and lows dropping into the low to mid 30s.
High pressure will remain dominant through the daylight hours on
Wednesday with highs reaching back near 60 degrees. Moisture will
begin to increase late Wednesday into Thursday as an upper trough
begins to swing across the eastern US, and sfc cyclogenesis
develops over the southern Plains. There is still considerable
disagreement regarding the northward extent of the sfc low and
where the Tennessee Valley will reside regarding the warm sector.
Have stuck with blended guidance for now, increasing rain and low
thunderstorm chances late Wednesday with medium (40-60%) rain
chances persisting through Friday morning. The main concern as it
stands now will be localized flooding, but will continue to
monitor trends in case a severe threat shifts north of the Gulf
Coastal region.

As the upper trough shifts east of the area early Friday, a cold
front will bring a much colder airmass to the region heading into
the weekend, and confidence is increasing that much if not all of
the area will experience sub-freezing lows Friday night into
Saturday.

&&

.AVIATION...
(00Z TAFS)
Issued at 551 PM CST Sat Nov 23 2024

VFR will be the prevailing flight category at the HSV/MSL
terminals this forecast period, with a sct coverage of Ci
anticipated both in a NW flow regime overnight and within
westerly/zonal flow aloft on Sun. With the region expected to
remain under the broader influence of a sfc high (currently
centered across southern portions of MS/AL), lgt/vrbl-calm winds
will support the development of BR/FG (perhaps as early as 5Z)
invof large water sources, and we have included a TEMPO group for
MVFR vsby reductions btwn 9-13Z at both airports. Low-lvl flow
will assume a southerly component after sunrise, with sustained
speeds of 5-10 kts and occasional higher gusts tomorrow aftn.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...

AL...Frost Advisory from 3 AM to 8 AM CST Sunday for ALZ001>010-016.

TN...None.

&&

$$

NEAR TERM...HC
SHORT TERM...HC
LONG TERM...25
AVIATION...70/DD