149  
FOUS30 KWBC 180801  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
301 AM EST TUE FEB 18 2025  
 
DAY 1  
VALID 12Z TUE FEB 18 2025 - 12Z WED FEB 19 2025  
 
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ALONG PORTIONS OF  
THE CENTRAL GULF COAST...  
 
STRENGTHENING SOUTHWESTERLY RETURN FLOW FROM THE GULF AHEAD OF AN  
AMPLIFYING UPPER-LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE COLD  
FRONT ARE EXPECTED TO DRAW DEEPER MOISTURE INTO PORTIONS OF THE  
CENTRAL GULF COAST WITH PWS CLIMBING TO 1.5"+. THIS MOISTURE,  
ALONG WITH INCREASING LIFT (VIA RIGHT-ENTRANCE REGION OF 120+ KT  
SUBTROPICAL JET STREAK) AND MARGINAL INSTABILITY (MU CAPE RISING TO  
NEAR 500 J/KG RIGHT ALONG THE IMMEDIATE COAST) ARE LIKELY TO BE  
SUFFICIENT FOR A RELATIVELY SHORT PERIOD OF HEAVY RAINFALL RATES  
(CONCENTRATED BETWEEN 00-09Z, AND LASTING FOR AROUND 3 HOURS TOTAL  
AT ANY ONE LOCALITY). WHILE THE POTENTIAL FOR TRAINING STORMS LOOKS  
RELATIVELY LOW (WITH INSTABILITY LARGELY LACKING PRIOR TO THE  
ARRIVAL OF THE PROGRESSIVE STORMS ALONG THE FRONT), CHANCES FOR ANY  
ISOLATED FLASH FLOODING APPEAR MAXIMIZED IN THE VICINITY OF LAKE  
CHARLES (WITH THE BEST INSTABILITY RESULTING IN HIGHEST ODDS FOR  
1-2"/HR RAINFALL RATES, AND LOCALIZED TOTALS OF 2-4" OVER A 3-HR  
PERIOD). ELSEWHERE (AND PARTICULARLY FARTHER NORTH FROM THE  
IMMEDIATE COASTLINE) RATES WILL LIKELY STRUGGLE TO SURPASS 1"/HR  
WITH A LACK OF INSTABILITY, THOUGH IN SOME PLACES THESE BRIEF  
DOWNPOURS MAY BE ENOUGH TO CAUSE LOCALIZED EXCESSIVE RAINFALL  
(PARTICULARLY INTO PORTIONS OF EAST-CENTRAL TX AND WEST-CENTRAL LA  
WHERE ANTECEDENT CONDITIONS ARE WETTER, ESPECIALLY COMPARED TO  
RELATIVELY DRY ANTECEDENT CONDITIONS IN SOUTH-CENTRAL LA).  
 
CHURCHILL  
 
DAY 2  
VALID 12Z WED FEB 19 2025 - 12Z THU FEB 20 2025  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
CHURCHILL  
 
DAY 3  
VALID 12Z THU FEB 20 2025 - 12Z FRI FEB 21 2025  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
CHURCHILL  
 
DAY 1 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/94EPOINTS.TXT  
DAY 2 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/98EPOINTS.TXT  
DAY 3 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/99EPOINTS.TXT  
 
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