SPC MD 901

MD 0901 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PARTS OF DEEP SOUTH TEXAS THROUGH MIDDLE TEXAS COASTAL AREAS

Mesoscale Discussion 0901
NWS Storm Prediction Center Norman OK
0940 AM CDT Tue May 20 2025

Areas affected...parts of Deep South Texas through middle Texas
coastal areas

Concerning...Severe potential...Watch unlikely 

Valid 201440Z - 201645Z

Probability of Watch Issuance...20 percent

SUMMARY...An isolated thunderstorm or two might still undergo
further intensification across parts of Deep South Texas through
middle Texas coastal areas into early afternoon.  This could be
accompanied by a risk for large hail and perhaps locally damaging
wind gusts, but it currently appears unlikely that a severe weather
watch will be needed.

DISCUSSION...Scattered thunderstorms have recently developed
near/south and east of the San Antonio vicinity.  This has occurred
despite the presence of notable inhibition associated with warm
elevated mixed layer air above a seasonably moist boundary layer. 
However, forcing for ascent accompanying a subtle mid/upper
perturbation, and associated speed maximum within the subtropical
westerlies, has apparently been sufficient to at least fleetingly
weaken the mid-level capping.  Based on the latest Rapid Refresh, it
is not clear how long this will persist, given warming forecast
around the 700 mb level across Deep South Texas and middle Texas
coastal areas during the next few hours.  But, given the strong
deep-layer shear, and thermodynamic profiles characterized by steep
mid-level lapse rates and sizable mixed-layer CAPE, conditionally
supportive of supercells capable of producing large to giant hail,
it may not entirely be out of the question that vigorous convection
could persist across middle Texas coastal areas through 16-18Z.

..Kerr/Hart.. 05/20/2025

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...HGX...CRP...EWX...

LAT...LON   28149720 28309825 29619870 29869627 29129457 27979566
            27989633 28149720 

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

Read more