795  
FOUS30 KWBC 060817  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
417 AM EDT FRI JUN 6 2025  
 
DAY 1  
VALID 12Z FRI JUN 06 2025 - 12Z SAT JUN 07 2025  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF  
THE SOUTH-CENTRAL PLAINS, THE LOWER OHIO, LOWER TENNESSEE AND  
MIDDLE MISSISSIPPI VALLEYS AND FROM EAST CENTRAL NEW YORK STATE  
INTO CENTRAL NEW ENGLAND...  
   
..SOUTH-CENTRAL PLAINS..  
 
THERE IS A STRONG MODEL SIGNAL FOR ANOTHER ROUND OF ORGANIZED  
CONVECTION LATE FRIDAY AFTERNOON INTO FRIDAY NIGHT/EARLY HOURS OF  
SATURDAY ACROSS THE SOUTH-CENTRAL PLAINS AS ADDITIONAL SHORTWAVE  
ENERGY IS FORECAST TO DROP EAST SOUTHEASTWARD FROM THE CENTRAL  
ROCKIES INTO THE CENTRAL TO SOUTHERN PLAINS FRIDAY INTO FRIDAY  
NIGHT/EARLY SATURDAY. THE LOW LEVEL FLOW IS EXPECTED TO AGAIN  
STRENGTHEN INTO THE WEST TO EAST ORIENTED FRONTAL ZONE ACROSS THE  
SOUTHERN PLAINS, SUPPORTING POTENTIAL FOR ANOTHER ROUND OF  
ORGANIZED CONVECTION IN THE VICINITY OF THIS FRONT. PW VALUES  
ALONG THIS FRONT WILL REMAIN ABOVE AVERAGE...2+ STANDARD DEVIATIONS  
ABOVE THE MEAN, SUPPORTING HEAVY PRECIP POTENTIAL. THERE IS FAIRLY  
GOOD MODEL CONSENSUS FOR AN AXIS OF HEAVY RAINS ALONG THIS FRONT  
FROM FAR SOUTHEAST CO/FAR SOUTHWEST KS, ACROSS MUCH OF OK INTO THE  
OK/KS/MO/AR BORDER REGION. THE SLIGHT RISK WAS DRAWN TO FIT THE  
AXIS OF THE HIGHEST HREF NEIGHBORHOOD PROBABILITIES FOR 2"+ AMOUNTS  
AND THE HREF EAS AXIS OF HIGHEST PROBABILITIES FOR 1"+ AMOUNTS. THE  
NEXT ROUND OF ORGANIZED CONVECTION WILL LIKELY TRACK ALONG THE SAME  
AREAS THAT ARE CURRENTLY RECEIVING HEAVY RAINFALL LATE THURSDAY  
EVENING INTO EARLY FRIDAY.  
 
...MID MISSISSIPPI VALLEY, LOWER OHIO VALLEY, LOWER TENNESSEE  
VALLEY...  
THE LEAD AREA OF SHORTWAVE ENERGY INITIATING CURRENT EARLY MORNING  
CONVECTION ACROSS THE SOUTHERN PLAINS WILL BE PUSHING TOWARD THE  
MID MISSISSIPPI VALLEY, LOWER OHIO AND LOWER TENNESSEE VALLEYS  
FRIDAY AFTERNOON/EVENING. SIMILAR TO AREAS UPSTREAM ALONG THE WEST  
TO EAST ORIENTED FRONTAL ZONE THAT EXTENDS INTO THE MID MS, LOWER  
OH,LOWER TN VALLEY, PW VALUES WILL BE ABOVE AVERAGE, 2+ STANDARD  
DEVIATIONS ABOVE THE MEAN. CONVECTION LIKELY TO ENHANCE FRIDAY  
AFTERNOON/EVENING AHEAD OF THESE HEIGHT FALLS IN THE MUCH ABOVE  
AVERAGE PW AXIS, SUPPORTING HEAVY RAIN POTENTIAL AND LOCALIZED  
FLOODING ISSUES. A SLIGHT RISK AREA WAS ADDED FROM THE PREVIOUS  
ISSUANCE, ALIGNED WITH WHERE THE AXIS OF THE HIGHEST HREF  
NEIGHBORHOOD PROBABILITIES FOR 2"+ AMOUNTS AND THE HREF EAS AXIS OF  
HIGHEST PROBABILITIES FOR 1"+ AMOUNTS ARE FORECAST.  
   
..SOUTHERN GREAT BASIN INTO THE CENTRAL TO SOUTHERN ROCKIES  
 
NOT A LOT OF CHANGES EXPECTED TO THE LARGE SCALE FLOW ACROSS THE  
SOUTHERN GREAT BASIN INTO THE CENTRAL ROCKIES. PW VALUES FORECAST  
TO REMAIN ABOVE AVERAGE WITH ADDITIONAL SHORTWAVE ENERGY MOVING  
ACROSS THE REGION IN THE WEST SOUTH WEST FLOW ALOFT. THIS SHOULD  
SUPPORT ANOTHER DAY OF WIDESPREAD SCATTERED CONVECTION AND  
LOCALIZED HEAVY RAIN AND ISOLATED RUNOFF ISSUES. NO SIGNIFICANT  
CHANGES MADE TO THE PREVIOUS MARGINAL RISK AREA ACROSS THIS REGION.  
   
..EAST-CENTRAL NEW YORK INTO CENTRAL NEW ENGLAND  
 
A SLIGHT RISK AREA WAS ADDED FOR PORTIONS OF EAST-CENTRAL NEW YORK  
STATE INTO CENTRAL NEW ENGLAND FROM CENTRAL TO SOUTHERN NEW  
HAMPSHIRE, ACROSS SOUTHEAST VERMONT, WESTERN MASSACHUSETTS INTO  
EAST CENTRAL NY STATE. THERE IS GOOD AGREEMENT IN THE LAST HI RES  
GUIDANCE FOR ENHANCING CONVECTION IN THE 1800 UTC FRIDAY TO 0000  
UTC SATURDAY PERIOD IN THE AXIS OF ABOVE AVERAGE PW VALUES ALONG  
THE SLOW MOVING FRONTAL BOUNDARY DRAPED ACROSS THIS AREA. THE  
SLIGHT RISK WAS DRAWN TO FIT WHERE THE AXIS OF HIGH HREF  
NEIGHBORHOOD PROBABILITIES ARE FOR 2 & 3"+ TOTALS. THIS CORRESPONDS  
ALSO TO WHERE THE HREF HOURLY PROBABILITIES FOR 1"+ TOTALS ARE  
HIGH IN THE 1800 UTC FRIDAY TO 0000 UTC SATURDAY PERIOD.  
 
ORAVEC  
 
DAY 2  
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...  
 
...LOWER ARKANSAS, LOWER MISSISSIPPI AND LOWER TENNESSEE VALLEYS..  
THE SECOND ROUND OF HEIGHT FALLS MOVING INTO THE CENTRAL TO  
SOUTHERN PLAINS DAY 1 WILL CONTINUE TO PUSH EAST SOUTHEAST TOWARD  
THE MID TO LOWER MS VALLEY, OH AND TN VALLEYS DURING DAY 2. UPPER  
DIFLUENCE IS FORECAST TO BE WELL DEFINED SATURDAY INTO SATURDAY  
NIGHT/EARLY SUNDAY IN AN AXIS OF ABOVE AVERAGE PW VALUES THAT WILL  
REMAIN ALONG THE WEST TO EAST ORIENTED FRONTAL BOUNDARY ACROSS  
THESE AREAS. THIS SHOULD SUPPORT POTENTIAL FOR ANOTHER ROUND OF  
ORGANIZED CONVECTION ALONG THIS FRONT. THERE IS SOME SPREAD WITH  
THE QPF AXES, BUT CONSENSUS THAT HEAVY AMOUNTS ARE POSSIBLE ALONG  
THIS FRONT. THE SLIGHT RISK AREA WAS EXTENDED APPROXIMATELY 50M TO  
100 MILES FARTHER TO THE SOUTHEAST ACROSS NORTHERN MS AND NORTHERN  
AL TO COVER THE CURRENT MODEL SPREAD.  
   
..EAST CENTRAL NY STATE INTO CENTRAL TO NORTHERN NEW ENGLAND  
 
ANOTHER ROUND OF CONVECTION POSSIBLE EARLY DAY 2 ALONG THE FRONTAL  
BOUNDARY PUSHING THROUGH THE NORTHEAST AS A SHARPENING NORTHERN  
STREAM TROF PUSHES EASTWARD ACROSS NORTHERN NY INTO NEW ENGLAND.  
THE HREF NEIGHBORHOOD PROBABILITIES FOR THE 12 HOUR PERIOD FROM  
1200 UTC SATURDAY TO 0000 UTC SUNDAY, ARE HIGH ALONG THIS FRONT FOR  
1 AND 2"+ AMOUNTS. THE PREVIOUS MARGINAL RISK AREA WAS EXTENDED  
FARTHER WEST INTO EAST CENTRAL NY STATE TO COVER THESE HIGHER 12  
HOUR PROBABILITIES. THERE MAY NEED TO BE AN UPGRADE TO THE RISK  
LEVEL IN FUTURE ISSUANCES DEPENDING UPON WHERE THE HEAVY RAINS  
OCCUR DURING DAY 1.  
 
ORAVEC  
 
DAY 3  
VALID 12Z SUN JUN 08 2025 - 12Z MON JUN 09 2025  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS NORTH TEXAS  
INTO SOUTHERN OKLAHOMA...  
   
..NORTH TEXAS/SOUTHERN OKLAHOMA  
 
ADDITIONAL SHORTWAVE ENERGY LIKELY TO PUSH EAST SOUTHEASTWARD LATE  
SUNDAY AFTERNOON/EVENING FROM THE LEE OF THE CENTRAL TO SOUTHERN  
ROCKIES INTO THE SOUTHERN PLAINS. 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 IS FAIRLY GOOD  
AGREEMENT ON THE DAY 3 QPF AXES IN THE MODELS. RESULTING IN GOOD  
CONTINUITY WITH THE SLIGHT RISK AREA. THE MARGINAL RISK AREA WAS  
EXTENDED FARTHER TO THE NORTHWEST INTO SOUTHEAST COLORADO TO COVER  
THE MODEL QPF SPREAD.  
 
...LOWER MISSISSIPPI VALLEY INTO THE SOUTHERN-CENTRAL APPALACHIANS  
AND MID-ATLANTIC...  
 
BROADLY DIFFLUENT MID TO UPPER LEVEL FLOW EXPECTED DAY 3 AHEAD OF  
THE HEIGHT FALLS PUSHING OUT OF THE MID TO LOWER MS VALLEY, TN AND  
OH VALLEY REGION. WITH PW VALUES EXPECTED TO BE ABOVE AVERAGE...1.5  
TO 2+ STANDARD DEVIATIONS ABOVE THE MEAN...WIDESPREAD SCATTERED  
CONVECTION POSSIBLE FROM THE LOWER MS VALLEY, ACROSS THE SOUTHERN  
TO CENTRAL APPALACHIANS AND INTO THE MID-ATLANTIC. THE PREVIOUS  
MARGINAL RISK AREA THAT WAS ACROSS THE SOUTH WAS EXTENDED NORTH  
THROUGH THE SOUTHERN TO CENTRAL APPALACHIANS AND INTO THE MID-  
ATLANTIC ACROSS THE LOWER FFG VALUES.  
 
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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