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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS64 KHUN 182336
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
636 PM CDT Thu Apr 18 2024

...New AVIATION...

.NEAR TERM...
(Tonight)
Issued at 246 PM CDT Thu Apr 18 2024

Afternoon temperatures have risen into the upper 70s/mid 80s
across the area thanks to the thinning of morning cloud cover.
Widespread showers and thunderstorms are developing to our north
and west, the more northern storms tied to the occluding upper low
and the ones farther south tied to a broad shortwave trough. SPC
mesoanalysis shows afternoon SBCAPE values in the 2000-3000 J/kg
range across the local area, but weaker shear has limited storm
intensity and organization so far. Will be closely monitoring
things to our west this afternoon, as the shortwave disturbance
nears the area and results in medium to high chances (50-80%) for
showers and thunderstorms later this evening. Given the amount of
instability in place, a few of these storms could become strong
enough to produce gusty to damaging winds and large hail. SPC has
maintained a slight risk over far NW portions of AL, where the
best combination of instability and wind shear is projected to
line up later this evening. At this time, it looks like the timing
for these storms will be from now to 10pm west of I-65 and
4pm-5am east of I-65 (the broad range of timing due to the pop-up
nature of thunderstorms with multiple convergent boundaries noted
on satellite at the moment).

Additional storms are likely in the morning near sunrise as the
main cold front tied to the aforementioned low nears the area.
Short term guidance shows some favorable overlap between
instability (1500-2500 J/kg) and bulk shear near 40kts that would
support the risk for a few strong/severe storms. Will most likely
see a broken line of decaying storms moving southeast through the
area toward the morning commute. With southerly flow and dense
cloud cover, overnight lows will be quite warm only falling to the
low to mid 60s.

&&

.SHORT TERM...
(Friday through Sunday)
Issued at 246 PM CDT Thu Apr 18 2024

Showers and storms will continue slowly pushing southeast through
the area tomorrow morning as the front continues to dig across the
Southeast. Depending on the timing, a few isolated strong/severe
storms could develop across southeast portions of the area late
tomorrow morning into the afternoon aided by diurnal heating. As
the front clears the area, expect cooler northwesterly flow and
dry conditions by tomorrow night. Overnight lows will fall into
the low to mid 50s, and will continue to cool on Saturday with
highs in the upper 60s/lower 70s. As zonal flow takes over aloft,
will keep low to medium chances (20-60%) for showers and storms
in the forecast through Sunday afternoon, with the best chances
south of the TN River Sunday morning and afternoon. Highs on
Sunday will be quite cool, with afternoon temps struggling to
reach above the upper 50s.

&&

.LONG TERM...
(Sunday night through Wednesday)
Issued at 113 AM CDT Thu Apr 18 2024

Monday will be dry but still cool with highs in the 60s as high
pressure at the surface overspreads the OH and TN valleys. Dry
weather should last through Tuesday with temperatures warming
back into the 70s. On Wednesday, upper troughing resulting from a
strong upper low in Quebec and Ontario, will bring a cold front
south through the TN valley. At this point, leaning toward a dry
forecast, but it is borderline and may need further changes later
if the models come into better agreement.

&&

.AVIATION...
-- Changed Discussion --
(00Z TAFS)
Issued at 636 PM CDT Thu Apr 18 2024

VFR conditions continue at both KMSL and KHSV for now. Showers/storms
are forecast to return to the area later this evening into the
overnight hours, bringing MVFR to IFR conditions as a result of
lowered cloud ceilings and visibilities. Low ceilings and
subsequent MVFR/IFR conditions are forecast to remain in place
through the end of the TAF period.
-- End Changed Discussion --

&&

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

$$

NEAR TERM...25
SHORT TERM....25
LONG TERM....17
AVIATION...HC