216  
FOUS30 KWBC 150803  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
403 AM EDT WED APR 15 2026  
 
DAY 1  
VALID 12Z WED APR 15 2026 - 12Z THU APR 16 2026  
 
...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL FOR THE GREAT  
LAKES AND NORTHERN OHIO VALLEY..  
 
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO FOCUS NEAR THE WEST-EAST  
ORIENTATED FRONTAL BOUNDARY DRAPED ACROSS THE OHIO VALLEY/GREAT  
LAKES REGION INTO THE NORTHEAST AS A WEAK SURFACE LOW TRAVERSES THE  
BOUNDARY AND INTERSECTS THE ABUNDANT MOISTURE AND INSTABILITY. MEANWHILE,  
THE LONGWAVE TROUGH WILL FINALLY BE MAKING PROGRESS TOWARD THE  
CENTRAL PLAINS AND THE DEEP LAYER MOISTURE AXIS AND INSTABILITY  
SHIFTS SLIGHTLY EASTWARD. THIS SETUP WILL BE CONDUCIVE FOR PERIODS  
OF HEAVY RAINFALL. MODELS ARE SUGGESTING AREAL AVERAGES OF 1 TO 3  
INCHES OCCURRING WITH SOME OVERLAP WITH RAINFALL FOOTPRINT FROM  
PRIOR DAYS. THE SLIGHT RISK REMAINS IN EFFECT FROM NORTHERN  
ILLINOIS TO SOUTHER MICHIGAN AND NORTHWEST OHIO TO ACCOUNT FOR  
UNCERTAINTY ON STORM TRACK AND THE SPREAD OF 2 INCH HREF 24 HR QPF  
NEIGHBORHOOD PROBABILITY.  
   
..EASTERN OKLAHOMA AND THE OZARKS  
 
CONVECTION IS EXPECTED TO BECOME MORE ACTIVE DURING THE AFTERNOON  
AND TRACK GENERALLY FROM THE SOUTHWEST TO NORTHEAST AHEAD OF THE  
APPROACHING TROUGH. EASTERN OKLAHOMA INTO THE OZARKS WILL BE IN  
THE RIGHT ENTRANCE OF THE JET STREAK, WHICH WILL HELP PROVIDE LIFT.  
AT THE SURFACE, HIGH PWATS AND SURFACE INSTABILITY WILL ONCE AGAIN  
PRIME THE ATMOSPHERE FOR HOURLY RAINFALL RATES OF AN INCH/HR. QPF  
GUIDANCE DOES SHOW A MAXIMUM OF 1-2 INCHES ACROSS THE REGION, BUT  
MODEL GUIDANCE SHOWS LITTLE TO NO PROBABILITY FOR ACCUMULATIONS  
EXCEEDING 2 INCHES. THEREFORE, A MARGINAL RISK IS MAINTAINED FOR  
THE RISK AREA. ADDITIONALLY, THE MORE FLASH FLOOD PRONE OZARK  
MOUNTAIN RANGE IS RELATIVELY DRY.  
   
..NORTHEAST  
 
REMNANTS OF THE STORMS ACROSS THE GREAT LAKES MAY BRING A ROUND OF  
SHOWERS AND STORMS IN THE MORNING, FOLLOWED BY ANOTHER ROUND OF  
HEAVIER SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. MODEL GUIDANCE  
SHOWS A CORRIDOR OF 1-1.5 INCHES RAINFALL WITH EMBEDDED HIGHER  
AMOUNTS DEPENDING ON THE MODEL. THE RELATIVELY LOWER FLASH GUIDANCE  
ACROSS WESTERN PENNSYLVANIA AND THE MORE URBAN FOOTPRINT OF AREAS  
SUCH AS CONNECTICUT AND NEW ENGLAND ALSO HELP CONFIDENCE OF  
EXPANDING THE MARGINAL EASTWARD.  
 
CAMPBELL/WILDER  
 
DAY 2  
VALID 12Z THU APR 16 2026 - 12Z FRI APR 17 2026  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOODING GUIDANCE IS  
LESS THAN 5 PERCENT.  
 
CAMPBELL  
 
DAY 3  
VALID 12Z FRI APR 17 2026 - 12Z SAT APR 18 2026  
 
...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL FOR NORTHERN  
MISSOURI, EASTERN IOWA AND NORTHWEST ILLINOIS...  
 
A BAND OF WEAKENING SHOWERS AND THUNDERSTORMS WILL PASS THROUGH  
THE OHIO VALLEY WITH THE LEAD SHORTWAVE TROUGH. MEANWHILE THE LONG  
WAVE TROUGH APPROACHING THE MIDWEST WILL HAVE BETTER LARGE SCALE  
ASCENT AND INSTABILITY TO YIELD BETTER AREAL COVERAGE OF QPF WITH A  
MORE FOCUSED SWATH OF HIGHER AMOUNTS ACROSS MISSOURI TO THE  
ILLINOIS/WISCONSIN BORDER. THE PREVIOUS SLIGHT RISK AREA WAS  
POSITIONED MORE OVER IOWA AND WISCONSIN, HOWEVER THE LATEST TRENDS  
SUGGEST A MODEST SOUTH/SOUTHEAST ADJUSTMENT TO NORTHERN MISSOURI,  
EASTERN IOWA, NORTHWEST ILLINOIS AND EXTREME SOUTHWEST WISCONSIN.  
WILL BE VALID FROM NORTHERN MISSOURI TO SOUTHWESTERN WISCONSIN FOR  
 
CAMPBELL  
 
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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