719
FXUS64 KHUN 201136
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
636 AM CDT Sun Apr 20 2025

...New AVIATION...

.NEAR TERM...
(Today)
Issued at 351 AM CDT Sun Apr 20 2025

Southwest flow aloft of 40-45 knots will persist across the TN
Valley through the duration of the near term period, as our region
will remain within the gradient between a subtropical high
situated off the southeastern Atlantic Coast and a deepening
shortwave trough (currently over the southern High Plains) that
will assume a negative tilt as it ejects northeastward into the
Mid-MO Valley later today. At the surface, light SE winds early
this morning will veer to SSE and strengthen after sunrise as the
local pressure gradient contracts in response to a developing area
of low pressure across north-central TX that will also deepen as
it lifts northeastward into northwestern MO. Although a few light
showers may occur (particularly across the northeastern portion of
the CWFA) as the southerly low-level jet steadily increases into
the 20-30 knot range by late this afternoon, most locations will
remain dry with a broken-overcast coverage of cirrostratus clouds
remaining intact. Highs will range from the u70s-l80s in elevated
terrain to the mid 80s in the valley.

&&

.SHORT TERM...
(Sunday night through Tuesday)
Issued at 935 PM CDT Sat Apr 19 2025

As the upper level low moves eastward toward the Tennessee Valley,
low to medium rain chances (20-50%) make their debut in NW AL
late Sunday night into Monday morning ahead of the cold front`s
arrival. Shower/thunderstorm chances are forecast to gradually
make their way eastward and increase throughout the late
morning/afternoon hours. While greater instability remains south
of our area, there is a low-medium chance we could have a few
stronger storms capable of producing gusty winds up to 40-50 mph
and small hail with DCAPE values around 300-500 J/kg as well as
deep low level lapse rates. In addition to this, moderate to heavy
rainfall could produce ponding of water in areas of poor drainage
or low- lying areas as PWATs near the 90th percentile per BMX
sounding climatology. Something we will be keeping an eye on to
limit strong storm potential will be how much the cloud cover and
precipitation during the morning hours limit instability during
the afternoon. Gusty, non-thunderstorm winds up to 20-25 mph
persist through Monday night as the increased pressure gradient
continues to influence the area. However, this is below local Wind
Advisory Criteria.

Medium to high rain chances (40-80%) are forecast to persist
through Tuesday as the front pushes southeastward through the
area and becomes stationary, bringing around an inch of rainfall
to the Tennessee Valley (with up to 1.25-1.5" in areas south of
the Tennessee River where heavier showers/thunderstorms are more
likely). Rainfall chances are forecast to decrease (but not
completely diminish) Tuesday night, dropping to around 30%. High
temperatures during this time remain in the 70s-80s with overnight
lows dropping into the 60s.

&&

.LONG TERM...
(Tuesday night through Saturday)
Issued at 935 PM CDT Sat Apr 19 2025

An unsettled pattern continues through the long term period with
several small shortwaves influencing the area, causing prolonged
low-medium rain chances through the week. After the aforementioned
cold front becomes stationary on Tuesday, it is forecast to make
its way back northwestward and return with another round of
rainfall. High temperatures through the week are forecast to
remain in the 80s with overnight lows in the 60s. For those who
are already tired of the warmer weather, the ongoing cloud cover
will provide relief from the heat as it persist through the
weekend.

&&

.AVIATION...
(12Z TAFS)
Issued at 636 AM CDT Sun Apr 20 2025

VFR conditions will prevail at the terminals today and this
evening, with development of sct Cu (by 16Z) beneath a bkn-ovc
layer of Cs. However, toward the end of the forecast period, low
stratus clouds and lgt SHRA will begin to impact MSL as a weak
cold front approaches the region from the NW, and MVFR conds have
been indicated in a PROB30 group from 11-12Z. Sfc winds will
strengthen to 10G18 kts from the SSE by 16Z, but should veer to
SSW this evening with sustained speeds of 5-10 kts. Although LLWS
may indeed become a concern as the southwesterly LLJ increases in
intensity this evening, a coherent period has not yet been
identified for inclusion of this in the forecast.

&&

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

&&

$$

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