450  
FOUS30 KWBC 070813  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
413 AM EDT SAT JUN 7 2025  
 
DAY 1  
VALID 12Z SAT JUN 07 2025 - 12Z SUN JUN 08 2025  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS THE LOWER  
ARKANSAS VALLEY, LOWER MISSISSIPPI VALLEY INTO THE LOWER TENNESSEE  
VALLEY AND OVER CENTRAL NEW ENGLAND...  
 
THE NEXT ROUND OF SHORTWAVE ENERGY PUSHING INTO THE CENTRAL TO  
SOUTHERN PLAINS EARLY SATURDAY MORNING WILL PROGRESS INTO THE LOWER  
MO VALLEY/MID MS VALLEY/OH VALLEY REGION DURING THE DAY SATURDAY.  
THIS UPPER TROF WILL BECOME MORE NEGATIVELY TILTED WITH A WELL  
DEFINED AREA OF UPPER DIFLUENCE PUSHING EASTWARD. CONVECTION  
LIKELY TO ENHANCE IN THIS BROAD UPPER DIFLUENCE REGION WHERE PW  
VALUES WILL REMAIN 1.5 TO 2+ STANDARD DEVIATIONS ABOVE THE MEAN  
ACROSS A LARGE REGION FROM THE OH VALLEY, SOUTH INTO THE MID TO  
LOWER MS VALLEY AND TN VALLEY. ACROSS THE NORTHERN PORTIONS OF THE  
PRECIPITATION AREA FROM THE LOWER OH/MID MS VALLEY REGION,  
CONSENSUS IS FOR THE NEXT ROUND OF PRECIP TO FALL JUST TO THE NORTH  
OF WHERE THE HEAVY AMOUNTS FELL OVER THE PAST 24 HOURS. THIS  
SHOULD REDUCE THE RISK OF RUNOFF ISSUES. GIVEN THAT THERE IS NOT  
EXPECTED TO BE A SIGNIFICANT OVERLAP OF DAY 1 PRECIP WITH THE  
PREVIOUS 24 HOURS OBSERVED PRECIP, THE RISK LEVEL WAS KEPT AS  
MARGINAL HERE.  
 
FARTHER TO THE SOUTH, NOT A LOT OF CHANGES MADE TO THE BROAD SLIGHT  
RISK AREA FROM THE LOWER AR, LOWER MS VALLEY, EAST INTO NORTHERN MS  
AND NORTHERN AL. THE SLIGHT RISK AREA CONTINUES TO FIT WELL WITH  
THE AXIS OF HIGH HREF NEIGHBORHOOD PROBABILITIES FOR 1 AND 2"+  
AMOUNTS THIS PERIOD. THERE MAY BE MORE THAN 1 ROUND OF CONVECTION  
TO MOVE ACROSS THIS REGION. THE INITIAL, EARLY DAY 1 FROM THE  
CONVECTION CURRENTLY ENHANCING OVER THE SOUTHERN PLAINS, FOLLOWED  
BY A SECOND ROUND LATE SATURDAY AFTERNOON ALONG THE SURFACE FRONTAL  
BOUNDARY. WITH EACH ROUND OF CONVECTION, HOURLY RAINFALL TOTALS OF  
.50-1"+ POSSIBLE.  
   
..SOUTHEAST NY STATE INTO NEW ENGLAND
 
 
ANOTHER ROUND OF CONVECTION LIKELY DAY 1 ALONG THE FRONTAL  
BOUNDARY PUSHING THROUGH THE NORTHEAST AS A SHARPENING NORTHERN  
STREAM TROF PUSHES ACROSS THE NORTHEAST. A SLIGHT RISK AREA WAS  
INTRODUCED FROM THE PREVIOUS ISSUANCE TO CORRESPOND TO WHERE THERE  
IS AN OVERLAP BETWEEN HEAVY PRECIP FROM FRIDAY AFTERNOON AND  
EXPECTED ADDITIONAL HEAVY PRECIP BETWEEN 1500 UTC SAT AND 0000 UTC  
SUN. THIS CORRESPONDS TO AN AREA FROM NORTH CENTRAL MA, ACROSS  
SOUTHERN NH INTO SOUTHWEST ME. IN THIS REGION THE LATEST HREF  
PROBABILITIES FOR .50 AND 1"+ HOURLY AMOUNTS ARE FAIRLY HIGH AND  
WHERE SOILS HAVE BECOME INCREASINGLY SATURATED.  
 
ORAVEC  
 
DAY 2  
VALID 12Z SUN JUN 08 2025 - 12Z MON JUN 09 2025  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS NORTHERN  
TEXAS AND SOUTHERN OKLAHOMA...  
   
..SOUTHERN PLAINS TO THE SOUTHEAST
 
 
THE LATEST GUIDANCE REMAINS CONSISTENT IN SHOWING ADDITIONAL  
SHORTWAVE ENERGY PUSHING EAST SOUTHEASTWARD LATE SUNDAY  
AFTERNOON/EVENING FROM THE LEE OF THE CENTRAL TO SOUTHERN ROCKIES  
INTO THE SOUTHERN PLAINS IN THE NORTHWEST FLOW ON THE SOUTH SIDE  
OF A STRONGER UPPER LEVEL LOW CENTERED OVER THE NORTH-CENTRAL  
UNITED STATES. THIS WILL AGAIN RE-STRENGTHEN THE LOW LEVEL FLOW  
INTO THE WEST TO EAST ORIENTED FRONT FORECAST TO REMAIN ACROSS THE  
SOUTHERN PLAINS, SUPPORTING ANOTHER ROUND OF ORGANIZED CONVECTION  
ALONG THE FRONT. THERE CONTINUES TO BE FAIRLY GOOD AGREEMENT ON  
THE POTENTIAL FOR AN AXES OF HEAVY PRECIP DAY 2, RESULTING IN GOOD  
CONTINUITY WITH THE SLIGHT RISK AREA WITH ONLY SOME SMALL CHANGES  
TO REFLECT THE LATEST FORECASTS. THIS NEXT ROUND OF ORGANIZED  
CONVECTION WILL LIKELY BE FAIRLY PROGRESSIVE, SIMILAR TO WHAT  
OCCURRED FARTHER TO THE NORTH THURSDAY NIGHT INTO EARLY FRIDAY AND  
FRIDAY NIGHT INTO EARLY SATURDAY. STILL, THERE IS LIKELIHOOD OF  
WIDESPREAD RAINFALL AMOUNTS OF 1-2" WITH LOCALIZED AMOUNTS UP TO  
4". SOILS ARE NOT AS SATURATED AS AREAS FARTHER NORTH, BUT  
LOCALIZED RUNOFF ISSUES ARE STILL LIKELY.  
   
..CENTRAL APPALACHIANS INTO THE MID-ATLANTIC
 
 
THE NEGATIVELY TILTED SHORTWAVE COMING OUT OF THE OH VALLEY LATE  
DAY 1 WILL PUSH ACROSS THE CENTRAL APPALACHIANS INTO THE MID-  
ATLANTIC DAY 2. THERE IS A FAIR AMOUNT OF SPREAD WITH MODEL QPFS,  
BUT A SIGNAL FOR THE POTENTIAL FOR LOCALLY HEAVY RAINS IN THE  
CONTINUED WELL DEFINED AREA OF UPPER DIFLUENCE AHEAD OF THESE  
HEIGHT FALLS IN AN AXIS OF ABOVE AVERAGE PW VALUES...1.5 TO 2+  
STANDARD DEVIATIONS ABOVE THE MEAN. THERE WERE ONLY SOME MINOR  
CHANGES MADE TO THE PREVIOUS MARGINAL RISK ACROSS THE CENTRAL  
APPALACHIANS INTO THE MID- ATLANTIC, CONTINUING TO CENTER IT ACROSS  
AREAS THAT HAVE LOWER FFG VALUES.  
 
ORAVEC  
 
DAY 3  
VALID 12Z MON JUN 09 2025 - 12Z TUE JUN 10 2025  
 
...THERE IS A MARGINAL OF EXCESSIVE RAINFALL ACROSS THE SOUTHERN  
PLAINS, LOWER MISSISSIPPI VALLEY, NORTHEAST THROUGH THE TENNESSEE  
VALLEY, UPPER OHIO VALLEY AND INTO THE EASTERN GREAT LAKES...  
 
THERE IS GOOD AGREEMENT IN THE LATEST GUIDANCE WITH THE SLOW  
EASTWARD PUSH OF THE CLOSED LOW THROUGH THE UPPER LAKES DAY 3 AND  
THE BROAD UPPER TROFFING EXTENDING SOUTH OF THIS CENTER THROUGH THE  
MS AND OH VALLEYS. A BROAD REGION OF ABOVE AVERAGE PW VALUES WILL  
CONTINUE TO STRETCH ACROSS THE SOUTHERN TIER FROM THE SOUTHERN  
PLAINS, EAST ACROSS THE LOWER MS VALLEY AND INTO THE SOUTHEAST  
ALONG AND AHEAD OF THE LEAD WEST TO EAST ORIENTED FRONT. ANOTHER  
AXIS OF ABOVE AVERAGE PW VALUES WILL PUSH NORTHEASTWARD ACROSS THE  
TN AND OH VALLEYS INTO THE LOWER LAKES AHEAD OF A SECONDARY FRONT  
ROTATING THROUGH THE CYCLONIC FLOW ON THE SOUTHEAST SIDE OF THE  
STRONG CLOSED LOW OVER THE UPPER LAKES. ALONG EACH FRONTAL  
BOUNDARY, WIDESPREAD MODERATE TO LOCALLY HEAVY PRECIP TOTALS ARE  
LIKELY. MODEL AGREEMENT, HOWEVER, IS NOT GREAT WITH PLACEMENT OF  
MAXIMUM AMOUNTS, LEADING TO OVERALL LOW CONFIDENCE IN WHERE  
ANYTHING BUT A MARGINAL RISK COULD BE DRAWN. OVERALL, THE PREVIOUS  
BROAD MARGINAL RISK AREA FITS WELL WITH THE LATEST MODEL QPF  
SPREAD, WITH NO SIGNIFICANT CHANGES MADE TO PREVIOUS OUTLOOK FOR  
THE NEW DAY 3 OUTLOOK.  
 
ORAVEC  
 
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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