123
FXUS64 KHUN 251509
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1009 AM CDT Wed Sep 25 2024

...New NEAR TERM...

.NEAR TERM...
(Rest of Today)
Issued at 1009 AM CDT Wed Sep 25 2024

Todays weather will continue to be influenced by a stalled cold
front draped over the area. Current observations indicate the
front is currently located in NW AL. Model guidance indicates the
front will linger in NW AL for most of the day and then slowly
push SE this evening. The frontal boundary will continue to
provide lift to support showers and thunderstorms along and to the
SE of the front through most of the day. Fortunately, the
overcast conditions will greatly limit instability keeping storms
sub severe.

As for rain, overnight totals were scattered with totals ranging
from a trace in NW and NE AL to near an inch along the I-65
corridor. HREF guidance indicates near an inch of additional
rainfall possible along and east of I-65 through the remainder of
the day today. This is significantly less than previously forecast
and will hopefully keep soils in NE AL from becoming fully
saturated prior to Helene. As the front pushes east late this
evening, rain chances will begin to decrease through the overnight
hours yielding a brief period of low rain chances this evening
through tonight before tropical impacts arrive, see short term for
more details.

&&

.SHORT TERM...
(Tonight through Friday night)
Issued at 233 AM CDT Wed Sep 25 2024

The front will drift more to the east closer to the I-65 corridor
tonight, with rainfall diminishing with the loss of weak buoyant
energy. Weak convergence along the front may still allow for some
shower/tstms overnight, mainly east of I-65. The influx of cooler
air will at least translate into lows tonight in the lower/mid
60s. The pattern will then change considerably starting Thu, as
Tropical Storm Helene in the western Caribbean lifts northward and
strengthens into a hurricane. Outer rain bands/squalls associated
with Helene will begin to spread northward into the eastern half
of the region. Periods of moderate/heavy rainfall can be expected
into Thu night, as the hurricane makes landfall along the FL Big
Bend region and then lifts to the NNE. Additional rainfall amounts
around 2-4 inches are possible Thu/Thu night, especially east of
I-65 and a Flood Watch will likely be needed for the eastern half
of the area during this time frame. Wind gusts east of I-65 could
also be around 20-30 MPH into Thu night. These speeds are just
below Wind Advisory criteria, although any change in the track of
Helene to the west once inland could result in higher winds/gusts.

The threat for localized/flash flooding could extend into Fri
morning for areas east of I-65, as the remnants of Helene begin to
lift N/E of the area and the upper low to the west drifts into the
lower MS Valley. Going more into the day Fri, the better moisture
convergence axis between these two systems will lift northward
into TN, allowing for a diminishing trend in the rainfall over
much of the area. This pattern continues into Fri night, as the
remnants of Helene begin to be absorbed into the upper low to the
west. Given the continued cloud cover/rainfall, highs Thu/Fri will
likely trend in the lower/mid 70s, with lows into early Sat predom
in the mid 60s/near 60F.

&&

.LONG TERM...
(Saturday trough Tuesday)
Issued at 233 AM CDT Wed Sep 25 2024

The upper low will then begin to lift N/E of the central TN Valley
this weekend, providing for a low chance of showers (20-30%) both
Sat/Sun with some decreasing cloud cover. Minimal rain chances are
expected into the first half of the work week as well, as a
reinforcing cold front out of the NW sweeps thru the region. With
the decrease in cloud cover/rainfall, highs this weekend will be
more in the mid/upper 70s, before climbing into the upper 70s/near
80F Mon/Tue. Overnight lows thru the latter half of the forecast
period also look to remain in the mid 60s/near 60F.

&&

.AVIATION...
(12Z TAFS)
Issued at 637 AM CDT Wed Sep 25 2024

Cigs are just above 3K ft heading into the morning hrs this Wed,
as a weak cold front crosses into NW AL. MVFR cigs near 3K ft are
expected to develop ahead of the front closer to the KHSV airfield
later this morning. Sct shra are also expected to form
along/ahead of the front late this morning and a TEMPO group has
been included for KHSV around 17-21Z to account for any reduced
cig/vis. PROB30 groups were then maintained later this afternoon
for both main terminals to account for any additional shra. Precip
is then expected to diminish this evening, with VFR conds
prevailing into early Thu morning.

&&

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

$$

NEAR TERM...RAD
SHORT TERM....09
LONG TERM....09
AVIATION...09