833
ACUS01 KWNS 050538
SWODY1
SPC AC 050537

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1237 AM CDT Sun May 05 2024

Valid 051200Z - 061200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
SOUTH TEXAS...

...SUMMARY...
Scattered strong to severe thunderstorms are possible across parts
of South Texas today. A few strong, to locally severe, storms are
also possible across the Mid-South and upper Ohio Valley.

...South TX to Mid-South...

Southern Plains short-wave trough will progress into east TX by
sunrise then eject across the Arklatex during the afternoon as a
weakening 500mb speed max translates into the lower MS Valley.
Low-level warm advection is not expected to be particularly strong
ahead of this feature, but a modest LLJ will shift across the
Arklatex into the middle TN Valley during the overnight hours.

Early this morning, an expansive MCS has evolved ahead of the short
wave over the southern Plains. This complex will propagate toward
the lower Sabine River Valley then possibly weaken early in the
period. Some airmass recovery is expected ahead of the MCS with
modest heating expected from northern LA into northern MS by mid
day. Of more concern is the trailing southwestern flank of the MCS
across south-central TX. Early-day convection will likely extend
across the TX Coastal Plain with more isolated activity farther
west. However, convective outflow will sag south and serve as the
focus for potential renewed robust convection later in the day.
Surface temperatures should only warm through the 80s across deep
south TX as east-southeasterly low-level flow will limit low-level
lapse rates. However, the boundary may prove adequate for isolated
supercells to develop within a sufficiently sheared environment for
sustained rotating updrafts. Large hail and damaging winds would be
the primary risk with the south TX activity.

Isolated-scattered convection is expected to evolve across the
Mid-South. While forecast lapse rates are poor, a few strong/severe
storms could evolve ahead of the aforementioned short wave. Locally
damaging winds and perhaps marginally severe hail are possible.

...Ohio Valley...

Strong short-wave trough will advance across the upper Great Lakes
into western QC by the end of the period. Southern influence of this
feature will glance the upper OH Valley such that a few strong
storms could evolve during the day. Surface front will be the
primary focus for convective development, but forecast soundings
show only modest surface-6km bulk shear, and do not exhibit
particularly steep lapse rates (6-6.5 C/km). Gusty winds and
marginally severe hail are the primary risks.

..Darrow/Flournoy.. 05/05/2024

$$