Clearpost.online It's your post, so post it!

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1129 AM CDT Sun Apr 17 2022

Valid 171630Z - 181200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS NORTHERN
LOUISIANA INTO SOUTHWEST MISSISSIPPI...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTHERN TEXAS...

...SUMMARY...
Large to very large hail, damaging wind gusts, and a few tornadoes,
are possible over parts of the lower Mississippi Valley/central Gulf
Coast region today into this evening.  Severe/damaging hail will be
the main threat with thunderstorms over parts of south Texas.

...Synopsis...
A low-amplitude trough is noted in mid-morning water vapor imagery
translating eastward across the Plains. An embedded vorticity
maxima/shortwave is noted within this trough moving across KS with a
broad swath of subsidence overspreading the southern High Plains.
Ascent associated with this feature is already overspreading the
southern Plains/lower MS valley this morning with scattered showers
and isolated thunderstorms noted across southeast OK in the vicinity
of a diffuse surface low and ahead of a modest cold front. This
activity is expected to increase in coverage and intensity through
the afternoon as it propagates along a surface warm front draped to
the east/southeast into the lower MS river valley. The surface cold
front will continue to push into southern/southeast TX and will be
the impetus for isolated thunderstorms this afternoon.

...Lower MS river valley...
A moist air mass is already in place across LA/southern MS this
morning with dewpoints in the low 70s. Morning soundings show this
moisture extends up to around 1 km with 7 C/km mid-level lapse
rates. With temperatures already warming into the upper 70s amid
broken low-level cumulus, any lingering inhibition will likely erode
by early afternoon with widespread 2000-2500 J/kg MLCAPE values. 12
UTC soundings also show elongated hodographs with effective bulk
shear values already near 40 knots. Increasing upper-level winds
attendant to the shortwave will boost deep-layer shear further
across the lower MS valley by mid afternoon. The kinematic profiles
will support supercells, but storm motions along the warm frontal
zone will likely favor a mix of quasi-discrete supercells to one or
more clusters that may amalgamate into a more organized linear mode.
Regardless, the favorable thermodynamic and kinematic environment
will be supportive of damaging winds and large to very large hail -
particularly across north-central LA into southwest MS where the
potential for more discrete modes on the edge of the best
instability is greatest. A tornado threat will exist along the warm
frontal zone where low-level veering wind profiles will support ESRH
values near 100-150 m2/s2. 

...South-central Texas...
Isolated thunderstorms are expected to develop along the surface
cold front as it moves into south-central and southeast TX this
afternoon. Mixed layer inhibition noted in 12 UTC RAOBs will likely
linger through mid/late afternoon with gradual erosion due to
morning stratus across the region. Glancing ascent from the passing
wave to the north co*bined with lift along the front should be
sufficient for a handful of elevated, isolated cells late this
morning with higher probability for surface based convection this
afternoon. Forecast soundings show straight, elongated hodographs
favorable for supercell splits, and moderate instability co*bined
with strong effective bulk shear will support the potential for
large to very large hail as well as damaging winds. While confidence
in this potential remains highest across the I-35 corridor in
south-central TX, the environment is supportive of severe convection
from the Rio Grande through east TX.  

...Northern MS through central GA...
The severe hail/wind potential this morning will likely persist into
the late evening and overnight hours across northern MS into central
GA as the upper-level wave shifts into the southeastern CONUS. While
lapse rates across this region are somewhat marginal in morning
soundings, cooling aloft and strengthening upper-level winds
associated with the approaching wave will support increasing
instability and deep-layer shear through the day. Lift ahead of the
wave and within a modest warm advection regime will support
scattered thunderstorms this evening into the overnight hours.
Sufficient boundary-layer moisture will be in place to support
adequate MUCAPE within a sheared environment for a severe hail/wind
risk.

..Moore/Hart.. 04/17/2022