Severe Storm Outlook Narrative (AC)
Issued by NWS

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
995
ACUS02 KWNS 121739
SWODY2
SPC AC 121737

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1237 PM CDT Sun May 12 2024

Valid 131200Z - 141200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM MUCH OF
EASTERN TEXAS EASTWARD ACROSS THE GULF COAST STATES...

...SUMMARY...
Severe thunderstorms are expected Monday over a large region from
central and east Texas across parts of the Gulf Coast states. The
potential may develop for corridors of significant wind gusts and
very large hail, and a few tornadoes.

...Synopsis...
A shortwave trough will move east from the central and southern
Plains Monday into the Middle to Lower MS Valley through Tuesday
morning, while an upper high remains centered over Cuba. As this
trough moves east, heights will lower gradually across the region,
with a slow flattening of the ridge along the Gulf Coast. Midlevel
winds of 50-60 kt will be common, while stronger 70-90 kt flow at
300 mb shifts northeastward with the shortwave trough from the
ArkLaTex into the OH/TN Valleys.

At the surface, a weak low/trough will develop from northern MO
southward across the ArkLaTex and into southern TX. A very moist air
mass will exist from eastern TX into the lower MS Valley, with
increasing moisture late in the period across southern AL, GA, and
FL as a warm front lifts north. The robust moisture will result in
widespread clouds and precipitation throughout the period, which
will complicate the forecast.

In general, a relatively large area of substantial moisture and
instability will stretch from TX eastward toward the central Gulf
Coast during the day, beneath moderate westerlies aloft which will
enhance deep-layer shear. Stronger low-level shear will be relegated
to the warm front area, from AL into GA and northern FL, with
various corridors of severe potential possible.

...Eastern TX into western GA...
A complex forecast exists for Monday, with multiple areas of
potential within a broad zone, and at various times of the day.
While significant wind and hail will clearly be possible,
predictability is low regarding the precise corridors of enhanced
risk potential.

Early on Monday, storms are expected to be ongoing from MS into AL
and the FL Panhandle, related to warm/moist advection near and north
of a warm front. Some of this activity immediately near the warm
front may have a hail and tornado risk, as instability rapidly
increases in proximity to stronger low-level effective SRH centered
over southern AL.

To the west, early-day storms are also anticipated from the ArkLaTex
into east-central TX, beneath cooler temperatures aloft and where
mid 70s F dewpoints will be in place. This activity may produce
large hail, and eventually grow upscale into larger clusters or an
MCS across eastern TX, LA and western MS through 00Z. Forecast
soundings show ample instability, and moderate mid to high level
winds, but with weak flow below 700 mb, suggesting MCS potential.

Depending on the track of that activity, and the position of any
outflows from the earlier storms farther east, the severe wind and
hail risk may overspread additional areas extending again into AL
and GA. As previously mentioned, potential air mass overturning and
condition of the unstable boundary layer are the main uncertainties,
and therefore the entire region remains in 15% Slight Risk category.
However, corridor(s) of Enhanced Risk may be considered into the day
1 period.

..Jewell.. 05/12/2024

$$