123  
FOUS30 KWBC 221519  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1019 AM EST THU JAN 22 2026  
 
DAY 1  
VALID 16Z THU JAN 22 2026 - 12Z FRI JAN 23 2026  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
A MESOSCALE CYCLONE APPEARS TO HAVE FORMED NEAR THE INTERSECTION  
OF A WEAK SURFACE TROUGH/FRONT EAST TO NORTHEAST OF BISCAYNE BAY.  
THIS COMBINATION HAS LED TO THUNDERSTORM DEVELOPMENT WITH HEAVY  
RAINFALL, WHICH UP UNTIL THIS POINT HAS ONLY IMPACTED SOUTHERN  
PORTIONS OF KEY BISCAYNE THOUGH SOME CELLS RECENTLY ARE  
THREATENING TO MOVE ASHORE A LITTLE FARTHER NORTH ACROSS KEY  
BISCAYNE AND NEAR FISHER ISLAND. THE AIRMASS ALONG AND EAST OF THE  
COAST IS SUFFICIENTLY MOIST AND UNSTABLE FOR THUNDERSTORMS WITH  
HEAVY RAINFALL, AND EFFECTIVE BULK SHEAR SUPPORTS THE FORMATION OF  
RANDOM MESOCYCLONES. THE LOW-LEVEL INFLOW TO THE EAST NORTH OF THE  
MESOCYCLONE RUNS COUNTER TO THE WESTERLY FLOW ALOFT, WITH THE  
COMBINATION LEADING TO MINIMAL CELL MOVEMENT. THE OVERALL THREAT OF  
HEAVIER RAINFALL MATERIALIZING OVER URBAN AREAS OF THE I-95  
CORRIDOR STILL APPEARS TO BE FAIRLY ISOLATED. THE OVERALL THREAT  
APPEARS TO WANE AFTER 19Z/2 PM EST WHEN THE GUIDANCE IMPLIES THAT  
THE MESOCYCLONE NEAR SOUTH FLORIDA DRIFTS EASTWARD. A NON- ZERO  
THREAT OF FLASH FLOODING EXISTS, BUT CONVECTIVE COVERAGE AND THE  
BREVITY OF THE THUNDERSTORM RISK PRECLUDES ANY ADDITION OF MARGINAL  
AREAS AT THIS TIME.  
 
ISOLATED SHOWERS ACROSS SOUTHERN CALIFORNIA MAY ALSO IMPACT  
PORTIONS OF THE TRANSVERSE AND PENINSULAR RANGES AS WELL, WITH  
BRIEF HEAVY RAIN OCCURRING NEAR BURN SCARS ACROSS THE AREA. THE AIR  
MASS SHOULD BE SUFFICIENTLY MOIST, WITH PRECIPITABLE WATER VALUES  
IN THE 0.75-1" RANGE. BUBBLES OF 100+ J/KG OF MU CAPE LIE OFFSHORE  
AT THE PRESENT TIME. THIS SHOULD MAXIMIZE HOURLY RAIN AMOUNTS IN  
THE 0.4" NEIGHBORHOOD. THE 12Z HREF PROBABILITIES OF 0.5"+ IN AN  
AREA ARE BELOW 15%, ALSO IMPLYING THAT LESSER HOURLY AMOUNTS ARE  
EXPECTED. THE THREAT FOR FLASH FLOODING HERE IS ALSO LESS THAN 5%  
ALTHOUGH AN ISOLATED INSTANCE OF EXCESSIVE RUNOFF CANNOT BE  
COMPLETELY RULED OUT.  
 
ROTH/COOK  
 
DAY 2  
VALID 12Z FRI JAN 23 2026 - 12Z SAT JAN 24 2026  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
COOK  
 
DAY 3  
VALID 12Z SAT JAN 24 2026 - 12Z SUN JAN 25 2026  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
COOK  
 
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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