MD 0933 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR DEEP SOUTH TEXAS
Mesoscale Discussion 0933
NWS Storm Prediction Center Norman OK
0618 PM CDT Sat Jun 03 2023
Areas affected...Deep South Texas
Concerning...Severe potential...Watch possible
Valid 032318Z - 040115Z
Probability of Watch Issuance...60 percent
SUMMARY...Storms spreading into the lower Rio Grande Valley may
gradually organize and eventually pose increasing risk for strong to
severe surface gusts while progressing toward lower Texas coastal
areas through 7-9 PM CDT.
DISCUSSION...Forcing for ascent associated with a subtle short wave
impulse digging toward the lower Rio Grande Valley has likely
contributed to the widespread ongoing vigorous thunderstorm
development. Storms initiated across the higher terrain to the west
of the river, where seasonably moist (upper 60s/lower 70s F surface
dew points) southeasterly upslope flow has contributed to large
mixed-layer CAPE in the presence of steep lapse rates.
While light westerly ambient deep-layer mean flow has contributed to
advection off the higher terrain, a somewhat less moist and more
strongly capped environment with more modest CAPE prevails in lower
elevations, across the Rio Grande River through much of Deep South
Texas. Still, aided by pronounced veering of the wind fields in
lower through mid-levels, deep-layer shear is moderate to strong.
Coupled with the mid-level forcing for ascent, it is possible that
convection will continue to overcome the inhibition, and gradually
organize during the next few hours, particularly as strengthening
surface cold pools begin to consolidate. If/when this occurs, a
localized severe hail/downburst threat may transition to potential
for more widespread strong to severe gusts as activity progresses
toward lower Texas coastal areas into this evening.
..Kerr/Guyer.. 06/03/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CRP...EWX...BRO...
LAT...LON 27490033 28750020 28049710 26339711 25689837 26010065
26590102 27490033
