205  
ACUS11 KWNS 201440  
SWOMCD  
SPC MCD 201440  
TXZ000-201645-  
 
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  
 
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