498  
AWUS01 KWNH 050937  
FFGMPD  
TXZ000-051305-  
 
MESOSCALE PRECIPITATION DISCUSSION 0595  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
536 AM EDT SAT JUL 05 2025  
 
AREAS AFFECTED...CENTRAL TX  
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY  
 
VALID 050935Z - 051305Z  
 
SUMMARY...THE POTENTIAL FOR LOCALLY CATASTROPHIC FLASH FLOODING IS  
EXPECTED TO CONTINUE OVER THE NEXT FEW HOURS OVER CENTRAL TX,  
EXTENDING THROUGH SUNRISE. EXTREME HOURLY RAINFALL NEAR AND IN  
EXCESS OF 4 TO 5 INCHES CAN BE EXPECTED AT TIMES. DANGEROUS /  
LIFE-THREATENING FLASH FLOODING IS ALREADY OCCURRING AND WILL  
CONTINUE FOR AT LEAST ANOTHER 2-4 HOURS.  
 
DISCUSSION...0915Z RADAR IMAGERY SHOWED THAT A SMALL CLUSTER OF  
HEAVY RAIN CONTINUED TO AFFECT CENTRAL TX, WITH THE HIGHEST  
RAINFALL INTENSITIES OVER WESTERN WILLIAMSON AND EASTERN BURNET  
COUNTIES. GAUGE DATA FROM THE LOWER COLORADO RIVER AUTHORITY  
(LCRA) SHOWED A 10.34 INCH TOTAL IN 3 HOURS ENDING 0910Z, 8 MILES  
SSW OF BETRAM AS RECENT TRENDS IN RADAR IMAGERY HAVE SHOWN THE  
HEAVIEST RAINFALL INTENSITIES SHIFTING NORTHWARD COMPARED TO A FEW  
HOURS AGO. THIS NORTHWARD SHIFT APPEARS TO BE TIED TO A NORTHWARD  
TRANSLATION OF A WEST-EAST ORIENTED INSTABILITY GRADIENT THAT  
BISECTED THE SMALL CONVECTIVE CLUSTER. LATENT HEAT RELEASE WITHIN  
THE THUNDERSTORM CLUSTER HAS REINVIGORATED A MESOSCALE VORTEX  
WHICH WAS LOCATED ALONG THE BURNET/WILLIAMSON COUNTY LINE AND HAS  
BEEN ALLOWING FOR THE DEVELOPMENT OF NEW UPDRAFTS TO ITS IMMEDIATE  
NORTH, FOLLOWING 20-30 KT OF SOUTHERLY 925-850 MB WINDS WITHIN THE  
ANOMALOUS PW ENVIRONMENT (2.0 TO 2.2 INCHES PER 09Z SPC  
MESOANALYSIS DATA).  
 
SOME CONTINUED NORTHWARD DEVELOPMENT IS EXPECTED OVER THE NEXT 2-4  
HOURS, ALTHOUGH THE CORE OF THE HEAVIEST RAIN NEAR THE MCV IS  
LIKELY TO REMAIN FARTHER SOUTH. WHILE THERE IS SOME UNCERTAINTY IN  
THE DURATION OF THE HEAVIEST RAINFALL WITH RAP FORECASTS OF  
925-850 MB WINDS SHIFTING EAST AND WEAKENING THROUGH 13Z,  
CONTINUED VERY HIGH RAINFALL RATES OF 3 TO 5+ INCHES IN AN HOUR  
ARE EXPECTED TO PERSIST FOR ANOTHER 1-3 HOURS WITH ADDITIONAL  
RAINFALL OF 5 TO 10 INCHES POSSIBLE ON TOP OF AN ALREADY SATURATED  
AND FLOODED REGION JUST WEST OF I-35. THESE RAINS ARE LIKELY TO  
CONTINUE THREATS FOR LOCALLY CATASTROPHIC FLOODING ACROSS A SMALL  
REGION OF CENTRAL TX THROUGH AT LEAST 12Z.  
 
OTTO  
   
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...EWX...FWD...SJT...  
 
ATTN...RFC...FWR...NWC...  
 
LAT...LON 32449795 32349756 31969740 31059754 30429784  
30359821 30599847 31019866 31549866 32099853  
32359819  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page