MD 0715 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR RIO GRANDE VALLEY
Mesoscale Discussion 0715
NWS Storm Prediction Center Norman OK
0452 PM CDT Sun May 07 2023
Areas affected...Rio Grande Valley
Concerning...Severe potential...Watch possible
Valid 072152Z - 080015Z
Probability of Watch Issuance...40 percent
SUMMARY...Currently monitoring convective trends across the Rio
Grande Valley for the possibility of isolated severe thunderstorms
capable of large hail and severe gusts.
DISCUSSION...Visible satellite imagery shows a couple of clusters of
thunderstorms over northern Mexico west of Del Rio and southwest of
Laredo on the higher terrain. A stout elevated mixed layer was
observed on the Del Rio 12 UTC raob. The associated warm
layer/capping inversion located near 875 mb will likely inhibit or
greatly limit surface-based development over south-central and Deep
South TX this afternoon. Nonetheless, strong heating has yielded
temperatures ranging from the mid 80s to the mid 90s across the Rio
Grande Valley. Moist low levels (mid 60s to lower 70s deg F surface
dewpoints) are contributing to a very unstable airmass (2500-4000
J/kg MLCAPE).
A belt of strong high-level flow will continue to reside across
northern Mexico and TX this evening. In the absence of appreciably
strong forcing for ascent, considerable uncertainty remains whether
a few thunderstorms will develop on the aggregate outflow from
storms in Mexico west and southwest of Laredo, or storms west of the
Del Rio eventually coalesce and move east into TX in the southern
part of the Edwards Plateau early this evening. If storms manage to
develop east across the Rio Grande (most likely near Del Rio), a
risk for large hail and severe gusts will probably accompany the
storms for a few hours before eventually dissipating by mid evening.
..Smith/Guyer.. 05/07/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CRP...EWX...BRO...
LAT...LON 29610178 30190104 30270048 29109954 27689892 26539905
26499933 29610178
