Area Forecast Discussion Issued by NWS Huntsville, AL
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000
FXUS64 KHUN 242339
AFDHUN
Area Forecast Discussion
National Weather Service Huntsville AL
639 PM CDT Sun Mar 24 2024
...New AVIATION...
.NEAR TERM...
(Tonight)
Issued at 322 PM CDT Sun Mar 24 2024
Ridging extending south of a surface high pressure system over
Quebec, continued controlling the weather over the eastern CONUS.
Although the surface flow has become ESE (after earlier being
light from the NE) had increased to 10-20 mph with stronger
gusts. Even with thin, high altitude clouds overspreading the
area from the west (somewhat lowering a solar heating potential),
early afternoon temperatures have slowly warmed into the
mid/60s to near 70. These readings are close to seasonal norms.
A potent storm system now forming over the High Plains was
producing very strong winds from KS to eastern NM, with some gusts
over 70 mph noted in West TX. This system as it moves to the east
will also bring stronger winds to this area over the next couple
of days.
Otherwise, not as cool tonight with lows ranging from the lower
40s our eastern areas (where colder air is still present) to the
lower 50s west. Winds from the SE will remain elevated in the
15-25 mph range and gusty. Gusts above 40 mph are possible in the
in the higher elevations of the Tennessee Valley.
&&
.SHORT TERM...
(Monday through Wednesday)
Issued at 322 PM CDT Sun Mar 24 2024
Windy conditions are expected on Monday as the above mentioned
storm system to our west deepens. The synoptic cyclone appears
will "bottom out" in the mid 980s mb range (sea-level pressure)
over western KS late tonight before slowly filling on Mon. As
such, the winds speeds will become high enough for a Wind
Advisory, which is already out, effective from 1 PM Mon through
early Tue morning. Expect SE winds of 20-30 mph with gusts near 50
mph, especially in the higher terrain and those more exposed
locations.
Another item to contend with will be high chances of showers and
thunderstorms impacting the Valley beginning Mon evening. As the
parent low slowly moves to the north, a cold front trailing south
of it will near this area. Numerous showers and storms preceding
the front will begin impacting the Tennessee Valley Mon evening,
with rain chances ramping up from west to east in the evening and
overnight. A strong wind field over the area, with usual turning
in direction will make for very sheared environment as we go into
Mon night. Storm relative helicity values exceed 1000 m/s from
some of the models. But lower level buoyancy and CAPE values will
fortunately remain on the lower side here before a main line of
convection arrives. The line of convection resembling a weak Quasi
Linear Convective System per the Convective Allowing Models
should remain on a weakening trend as it traverses the area.
BUT...although the line overall should be weakening as it moves
further east, it could still produce severe weather. Strong to
damaging wind gusts are the main threat, with a higher risk more
to the west. The Storm Prediction Center has placed the western
half of the area into a Marginal 1/5 risk for severe weather.
Although the system should not feature too much overall
instability, it will not fall short far as moisture content.
Precipitable water amounts in the late Mon/early Tue time frame
sharply ramp up to 1.3-1.5" or 75-90% percentile range this time
of year. Thus very heavy rainfall is possible with this system Mon
night into Tue morning. Some of the models were hinting that some
training of showers which could produce excessive rainfall. Thus
a Slight risk for excessive rainfall remains over NW AL. The
heaviest rain with this system appears will fall on areas west of
I-65. The heaviest showers should end Tue morning. Chances for
showers should taper off from west to east during Tue. The cold
front trailing from the parent low (by this time over western
Great Lakes) should move across the area Tue night, bringing
another shot of colder air to the region. Wednesday will feature a
return of dry weather.
High temperatures on Mon should warm only into the 60s, as clouds
increase ahead of the showers. Even with clouds and rain chances
Tue, highs should warm into the mid 60s to around 70 before the
front passes. A bit cooler for the mid week with highs in the 60s.
&&
.LONG TERM...
(Wednesday Night through Saturday)
Issued at 330 AM CDT Sun Mar 24 2024
Once the aforementioned system progresses to the east, surface
high pressure will take hold over the southeastern CONUS and
persist through the first part of next weekend. No rain is
anticipated during this time. High temperatures will be on a
warming trend, increasing from the 60s on Thursday to the lower to
mid 70s on Saturday. We may even see upper 70s the last day of
March! Lows are expected to start out in the mid to upper 30s for
Wednesday and Thursday nights, with possible frost late Thursday
night. However, expect lows to follow a similar warming trend
through the end of March.
&&
.AVIATION...
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(00Z TAFS)
Issued at 639 PM CDT Sun Mar 24 2024
VFR conditions will continue at the MSL/HSV terminals this
evening and overnight, featuring a bkn layer of cirrostratus and
SE wind of 12G20 knots. Elevated moisture return to the east of an
intensifying shortwave trough and related area of sfc low
pressure across the central Plains will contribute to development
of a lower stratus layer by 14Z that may provide bkn MVFR cigs
arnd 2500 ft for much of the day. Although some shower activity
(preceding a squall line associated with the storm system to our
west) may begin to spread into northwest AL prior to the end of
the TAF period, greater chances for SHRA/TSRA will occur after
25/0Z and we will leave the TAFs dry at this point. SE winds will
increase to 20G35 knots late tomorrow morning, and although this
(by definition) will preclude mentioning LLWS in the TAFs, SSE
flow just off the surface will steadily increase throughout the
day, and LLWS may ultimately be warranted after 21Z.-- End Changed Discussion --
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Wind Advisory from 1 PM Monday to 7 AM CDT Tuesday for
ALZ001>010-016.
TN...Wind Advisory from 1 PM Monday to 7 AM CDT Tuesday for TNZ076-
096-097.
&&
$$
NEAR TERM...RSB
SHORT TERM...RSB
LONG TERM...26
AVIATION...70/DD