Tornado Warning 36, NWS Huntsville, AL

Area Forecast Discussion
National Weather Service Huntsville AL
1145 AM CDT Tue May 20 2025

...New AVIATION...

.NEAR TERM...
(Rest of Today and Tonight)
Issued at 1106 AM CDT Tue May 20 2025

Morning convection that developed just east of the Mississippi
River has weakened somewhat as it pushed eastward and the initial
LLJ jet lifted northward. Still, given the very moist environment
and even a lower amount of uncapped instability, these storms
should persist into the early afternoon across mainly southern
middle Tennessee and locations near the AL/TN border in northern
Alabama through 1-2 PM. Most of this activity will remain
subsevere -- with gusty winds being the main threat with this
activity

Our attention will quickly turn to the mid/late afternoon, as a
more robust threat for severe weather develops along and ahead of
a cold front. The initial cloud cover from this morning convection
will gradually dissipate by the early afternoon, with ample
sunshine and southerly flow rapidly helping to destabilize the
atmosphere. By mid/late afternoon, guidance is hinting at between
2000-3000 J/kg of SBCAPE/MLCAPE with bulk shear values increasing
to 40-50 kts by the late afternoon and evening hours with a
developing 850-700 mb jet. This feature will serve as a forcing
mechanism to drive clusters of thunderstorms from the mid/late
afternoon through the evening hours. The favored storm mode will
be supercells and or line segments with embedded supercells that
will impact the area from roughly a 4 PM to Midnight timeframe.

An additional focus for convection as we destabilize this
afternoon may be a few residual outflow boundaries set down by
this morning convection. Should this activity develop during the
mid afternoon, a prefrontal round of supercells may be realized
across the area, followed by another line of storms (with embedded
supercells) later this evening. The atmosphere should be primed
for damaging winds (some 60-70+ MPH). Additionally, hodographs
indicating sufficient low- level backing of the winds to result in
some curvature in the lowest 0-1 km. By this afternoon, SRH values
in the 150-250 m2/s2 may be realized in right-moving storms -- and
even storms moving with the mean flow will more than sufficient
SRH for a tornado threat (with a strong tornado or two possible if
one or two supercells become dominant). This activity will wane
after the front sweeps through late this evening, with most storms
coming to an end by Midnight.

&&

.SHORT TERM...
(Wednesday through Friday)
Issued at 1106 AM CDT Tue May 20 2025

A cooler and more stable air mass will advect into the Tennessee
Valley behind the cold front, with dry conditions in the forecast
for the remainder of the work week. In fact, temperatures will be
downright enjoyable for late May into Memorial Day weekend as
highs will remain in the mid 70s to lower 80s! With plenty of
sunshine to enjoy, this will be an excellent timeframe for outdoor
activities.

&&

.LONG TERM...
(Friday through Monday)
Issued at 918 PM CDT Mon May 19 2025

A northwest flow pattern takes shape as we reach the end of the
work week and move into the weekend. Moisture advection begins to
increase this weekend, hence making the atmosphere more unstable
and increasing the potential for showers and thunderstorms. As is
typical with a northwest flow pattern this time of year, we will
have to watch out for upstream MCS development. Depending on where
those systems propagate will determine how active a pattern the
Tennessee Valley will see. Hence, kept blended PoPs through the
Memorial Day Weekend given this uncertainty. Overall, temperatures
will be near climatological normals for this time of year with
afternoon highs this weekend in the upper 70s to lower 80s.

&&

.AVIATION...
(18Z TAFS)
Issued at 1145 AM CDT Tue May 20 2025

SHRA/TSRA will develop later this afternoon and evening
potentially impacting TAF sites between 22-04z. Have included a
TEMPO at both terminals to support a more specific window, but
amendments in timing (and AWWs) may be needed during this
timeframe. Winds will also remain gusty out of the SW ahead of a
cold front this afternoon and evening, before shifting to the NW
in wake of the front after Midnight.

&&

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

NEAR TERM...AMP
SHORT TERM....AMP
LONG TERM....GH
AVIATION...AMP.24

Special Weather Statement
National Weather Service Huntsville AL
1004 AM CDT Tue May 20 2025

ALZ001-002-201545-
Lauderdale AL-Colbert AL-
1004 AM CDT Tue May 20 2025

...A STRONG THUNDERSTORM WILL IMPACT LAUDERDALE AND NORTHERN COLBERT
COUNTIES THROUGH 1045 AM CDT...

At 1004 AM CDT, Doppler radar was tracking a strong thunderstorm over
Pickwick Landing State Park, moving east at 45 mph.

HAZARD...Wind gusts of 50 to 55 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Green Hill, Center Star, Killen, Threet, Zip City,
Underwood-Petersville, St. Florian, Florence, Riverton, and Wright.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3500 8749 3481 8744 3480 8811 3489 8810
      3492 8816 3501 8820
TIME...MOT...LOC 1504Z 259DEG 40KT 3502 8823

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...55 MPH

JMS

Special Weather Statement
National Weather Service Huntsville AL
1151 AM CDT Tue May 20 2025

ALZ001-002-201715-
Lauderdale AL-Colbert AL-
1151 AM CDT Tue May 20 2025

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN LAUDERDALE AND
NORTHWESTERN COLBERT COUNTIES THROUGH 1215 PM CDT...

At 1150 AM CDT, Doppler radar was tracking a strong thunderstorm near
J P Coleman State Park, moving east at 25 mph.

HAZARD...Wind gusts in excess of 30 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Riverton, Wright, Threet, and Waterloo.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3501 8809 3501 8779 3488 8772 3481 8811
      3489 8810 3492 8816 3496 8817 3497 8819
TIME...MOT...LOC 1650Z 252DEG 23KT 3489 8814

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...30 MPH

JMS