MD 1711 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR UPPER TX COASTAL PLAIN
Mesoscale Discussion 1711
NWS Storm Prediction Center Norman OK
0139 AM CDT Fri Jul 26 2024
Areas affected...Upper TX Coastal Plain
Concerning...Severe potential...Watch unlikely
Valid 260639Z - 260845Z
Probability of Watch Issuance...5 percent
SUMMARY...Potential exists for a brief tornado through about dawn
with slow-moving, isolated thunderstorms over the Upper Texas Gulf
Coastal Plain. The limited spatiotemporal extent and low probability
of occurrence should preclude a watch issuance.
DISCUSSION...Persistent low-level warm theta-e advection has
supported scattered low-topped convection from the Mid to Upper TX
Gulf Coast into southeast TX. One cell near the north end of
Galveston Bay has recently deepened into a slow-moving thunderstorm,
drifting northeast at 10 kts. HGX VWP has sampled 0-1 km shear
around 20 kts with surface southeasterlies veering to the south at 1
km. The enhancement to hodograph curvature is nearly exclusively in
the low-levels, with a nearly unidirectional southwesterly wind
profile above 2 km. As such, transient supercell structure may
occur. This would seemingly be most probable within this portion of
the warm-advection regime given a relatively larger thermal
gradient, inferred by surface temperatures in the low 80s over
Galveston Island to low to mid 70s with northern extent in southeast
TX. The concern in this scenario is if the transient supercell
structure can briefly intensify to produce a tornado, although a
downburst or two is also possible. With time, enhanced low-level
flow should subside/shift northward, and likely curtail the threat
after daybreak.
See WPC MPD 0731 for information on the heavy rain/flash flooding
potential.
..Grams/Guyer.. 07/26/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LCH...HGX...
LAT...LON 30399509 30739474 30639410 30099403 29619426 29269482
29209534 30199520 30399509