SPC May 16, 2024 2000 UTC Day 1 Convective Outlook

SPC May 16, 2024 2000 UTC Day 1 Convective Outlook

SPC 2000Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0253 PM CDT Thu May 16 2024

Valid 162000Z – 171200Z

…THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHEAST TX
AND SOUTHWEST LA…

…SUMMARY…
Scattered severe thunderstorms are expected into tonight across
parts of Texas and Louisiana. The most concentrated corridor for
damaging winds should occur across southeast Texas into southwest
Louisiana.

…20Z Update…
Minor changes have been made to reflect latest observational and
near-term guidance trends. Expectation is still for upscale growth
into an MCS with increasing storm organization through this evening,
focused on southeast TX into southwest LA. Otherwise, large to very
large hail will remain possible along and north of the composite
cold front/trailing outflow westward from the TX Hill Country to the
Permian Basin.

..Grams.. 05/16/2024

.PREV DISCUSSION… /ISSUED 1133 AM CDT Thu May 16 2024/

…Central TX to southern LA through tonight…
Multiple clusters of thunderstorms are ongoing this morning across
north and central TX, generally along and to the immediate cool side
of a composite outflow boundary. Rich low-level moisture (100 mb
mean mixing ratios 16-18 g/kg), steep midlevel lapse rates of 8-9
C/km and large buoyancy (MLCAPE near or above 3000 J/kg) are present
south of the storms, along with sufficient deep-layer shear for
organized clusters/supercells. Thus, some upscale growth and
increased storm organization is expected from late morning into the
afternoon, as storms move east-southeastward along the
moisture/buoyancy gradient across central and southeast TX.
Damaging wind of 60-75 mph will be possible with embedded bowing
segments, while isolated very large hail will be possible with
supercells on the south flank of the larger storm cluster(s). A
couple of tornadoes will also be possible with embedded circulations
and/or favorable storm interactions near or south of the composite
outflow boundary. One or more clusters/bowing segments could
persist into tonight across southern LA.

Other storms will likely form immediately ahead of the primary
shortwave trough moving from southern NM toward west TX. Given the
ongoing reinforcement of the rain-cooled air mass, any convection
this afternoon from the Permian Basin into the Edwards Plateau will
likely be elevated atop the outflow spreading southwestward. Wind
profiles will favor supercells, with the primary threat of large
hail.

…Elsewhere…
No substantial changes to the low-end severe threats in the MRGL
areas across the Ozarks, WI, and southeast FL.

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