925  
FOUS30 KWBC 052017  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
417 PM EDT THU JUN 5 2025  
 
DAY 1  
VALID 16Z THU JUN 05 2025 - 12Z FRI JUN 06 2025  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF  
THE SOUTH-CENTRAL PLAINS...  
   
..CENTRAL TO SOUTHERN PLAINS
 
 
WITH SCATTERED TO WIDESPREAD STORMS EXPECTED ACROSS MUCH OF THE  
COUNTRY IN AN ACTIVE LATE SPRING PATTERN, A LOCALLY HIGHER THREAT  
FOR FLASH FLOODING EXISTS OVER PORTIONS OF THE CENTRAL/SOUTHERN  
PLAINS WHERE GREATER COVERAGE OF HEAVY RAINFALL IS EXPECTED WITH  
THE DEVELOPMENT OF A CONVECTIVE SYSTEM LATER THIS EVENING. AN  
ENVIRONMENT VERY CONDUCIVE TO THUNDERSTORM DEVELOPMENT WILL EVOLVE  
TODAY AS A WEAK TRIPLE POINT DEVELOPS IN SOUTHEASTERN COLORADO WITH  
HIGH MOISTURE, INSTABILITY IN PLACE SOUTH OF A WARM FRONT AND  
AHEAD OF A DRYLINE EXTENDING SOUTHWARD THROUGH THE SOUTHERN HIGH  
PLAINS. AFTERNOON CONVECTION DEVELOPING OFF THE RATON MESA/HIGH  
PLAINS WILL FEED OFF THE HIGHER THETA-E AIR AND STRENGTHENING LOW  
LEVEL FLOW AHEAD OF THE TRIPLE POINT INTO THE EVENING HOURS,  
EXPANDING IN COVERAGE AS COLD POOLS COMBINE/MATURE AND WITH ANY  
ADDITIONAL DEVELOPMENT EASTWARD ALONG THE WARM FRONT. ANOMALOUSLY  
HIGH MOISTURE IN PLACE MAY LEAD TO RAIN RATES UPWARDS OF 2-2.5" PER  
HOUR. WHILE THE SYSTEM SHOULD REMAIN PROGRESSIVE, THE HIGH RAIN  
RATES AND STORM COVERAGE WILL BRING THE THREAT FOR LOCALLY HEAVY  
RAIN TOTALS AS HIGH AS 3-4" AND SCATTERED INSTANCES OF FLASH  
FLOODING ALONG THE SYSTEM PATH. THIS PATH IS CURRENTLY MOST LIKELY  
FROM SOUTHWESTERN KANSAS/THE OKLAHOMA PANHANDLE/THE NORTHEASTERN TX  
PANHANDLE LATER THIS EVENING EAST-SOUTHEAST THROUGH SOUTHERN  
KANSAS AND NORTHERN OKLAHOMA INTO THE EARLY MORNING HOURS FRIDAY.  
ELSEWHERE, ADDITIONAL INDIVIDUAL STORMS AHEAD OF THE DRYLINE  
SOUTHWARD THROUGH THE TEXAS PANHANDLE/WEST TEXAS WILL ALSO BRING  
THE THREAT FOR SOME LOCALLY HEAVY DOWNPOURS AND ISOLATED FLASH  
FLOODING.  
   
..SOUTHERN GREAT BASIN INTO THE SOUTHERN TO CENTRAL ROCKIES
 
 
ANOTHER DAY OF SCATTERED TO WIDESPREAD DIURNAL CONVECTION IS  
EXPECTED THROUGHOUT THE REGION WITH UPPER-TROUGHING AND COLDER  
TEMPERATURES ALOFT AND THE PRESENCE OF A LINGERING FRONTAL  
BOUNDARY. ANOMALOUSLY HIGH MOISTURE (PWS UPWARDS OF 2-2.5 STANDARD  
DEVIATIONS ABOVE THE MEAN) MAY LEAD TO SOME LOCALLY HEAVY DOWNPOURS  
WITH RAIN RATES OF 0.5-1" BRINGING THE THREAT FOR SOME ISOLATED  
INSTANCES OF FLASH FLOODING, PARTICULARLY FOR TERRAIN SENSITIVE  
AREAS AND BURN SCARS.  
   
.LOWER LAKES, OH VALLEY INTO THE MID TO LOWER MS VALLEY
 
 
PW VALUES ALSO EXPECTED TO REMAIN ABOVE AVERAGE IN THE VICINITY OF  
THE NEARLY STATIONARY FRONTAL BOUNDARY STRETCHING FROM THE LOWER  
LAKES, SOUTHWEST INTO THE OH VALLEY AND MID TO LOWER MS VALLEY. A  
BROAD MARGINAL RISK AREA WAS MAINTAINED FROM PREVIOUS ISSUANCES FOR  
LOCALIZED HEAVY RAINFALL AND ISOLATED RUNOFF ISSUES. THE PREVIOUS  
MARGINAL RISK AREA WAS MODIFIED TO BETTER REFLECT LATEST MODEL  
CONSENSUS ON THE MODERATE TO LOCALLY HEAVY QPF AXIS.  
   
..EASTERN AND COASTAL CAROLINAS
 
 
THUNDERSTORMS CONTINUE THIS MORNING/EARLY AFTERNOON IN A MODIFYING  
AIRMASS LIFTING NORTHWARD THROUGH THE CENTRAL/EASTERN/COASTAL  
CAROLINAS EAST OF A WEAK SURFACE LOW. ANOMALOUSLY HIGH MOISTURE  
VALUES STREAMING IN FROM THE ATLANTIC (PWS 2-2.5 STANDARD  
DEVIATIONS ABOVE THE MEAN) AND INCREASING INSTABILITY (ML CAPE  
AROUND 1000 J/KG) MAY LEAD TO SOME EFFICIENT RAINFALL RATES OF 1-2"  
PER HOUR. WHILE THE HEAVIEST RAINFALL IS EXPECTED TO REMAIN  
OFFSHORE AND FFGS REMAIN HIGH, THESE RATES MAY LEAD TO SOME  
ISOLATED FLASH FLOODING CONCERNS, PARTICULARLY FOR COASTAL  
LOCATIONS THAT MAY SEE A FEW REPEATED ROUNDS OF STORMS LIFTING  
NORTHWARD. THE THREAT SHOULD DIMINISH THROUGH THE EVENING HOURS AS  
THE LOW MOVES OFFSHORE.  
 
PUTNAM  
 
DAY 2  
VALID 12Z FRI JUN 06 2025 - 12Z SAT JUN 07 2025  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR MUCH OF  
OKLAHOMA INTO THE KANSAS, OKLAHOMA, MISSOURI, ARKANSAS BORDER  
REGION...  
   
..2030Z UPDATE
 
 
   
..OKLAHOMA INTO THE OK/KS/MO/AR BORDER AREA
 
 
ONGOING CONVECTION ASSOCIATED WITH AN MCS PASSING THROUGH EASTERN  
OKLAHOMA DURING THE DAY 1 PERIOD MAY CONTINUE INTO DAY 2 FRIDAY  
MORNING, WITH A CONTINUED RISK FOR LOCALLY HEAVY RAINFALL AND  
SCATTERED FLASH FLOODING. OTHERWISE, THE PREVIOUS FORECAST REMAINS  
ON TRACK, AND SIMILAR TO DAY 1 IN BOTH NATURE AND LOCATION, WITH  
THE EXPECTATION THAT AFTERNOON/EVENING THUNDERSTORMS DEVELOPING  
AHEAD OF A TRIPLE POINT LOW LOCATED OVER THE CENTRAL/SOUTHERN HIGH  
PLAINS WILL GROW UPSCALE INTO AN MCS. THIS SYSTEM SHOULD TRACK  
EAST-SOUTHEASTWARD THROUGH OKLAHOMA LATE FRIDAY NIGHT/EARLY  
SATURDAY WITH AN ATTENDANT RISK FOR LOCALLY HEAVY RAINFALL RATES OF  
1-2" AND TOTALS OF 2-4" LEADING TO SCATTERED INSTANCES OF FLASH  
FLOODING.  
   
..MID MS, OHIO, AND TENNESSEE VALLEYS
 
 
A COMPLEX FORECAST IS APPARENT FOR THIS REGION GIVEN THE POTENTIAL  
FOR AN ONGOING AND/OR INFLUENCE FROM AN OVERNIGHT MCS THURSDAY  
NIGHT/FRIDAY MORNING. HI-RES GUIDANCE SUGGESTS THAT AN MCS  
DEVELOPING OVER THE CENTRAL/SOUTHERN HIGH PLAINS AND PASSING  
EASTWARD THROUGH THE CENTRAL/SOUTHERN PLAINS THURSDAY NIGHT/FRIDAY  
MORNING WILL CONTINUE EASTWARD INTO THE MIDDLE  
MISSISSIPPI/OHIO/TENNESSEE VALLEYS FRIDAY AFTERNOON. ANY SUSTAINED  
CONVECTION MAY ALSO BE AUGMENTED BY REDEVELOPMENT ALONG ASSOCIATED  
OUTFLOW BOUNDARY(S), WHICH WOULD HELP TO FOCUS WHAT WOULD BE A MORE  
NEBULOUS DISTRIBUTION OF STORMS AND LEAD TO MORE WIDESPREAD,  
HIGHER RAINFALL TOTALS SUPPORTIVE OF A GREATER FLASH FLOOD THREAT.  
REGARDLESS OF THE INFLUENCE OF THIS MCS, THE PRIOR FORECAST REMAINS  
ON TRACK. THE PRESENCE OF AN ANOMALOUSLY MOIST, UNSTABLE AIRMASS  
ALONG AND AHEAD OF THE QUASI-STATIONARY FRONTAL BOUNDARY WILL BE  
ENOUGH TO TRIGGER SCATTERED TO WIDESPREAD THUNDERSTORMS CAPABLE OF  
LOCALLY HEAVY RAINFALL AND AT LEAST ISOLATED FLASH FLOODING.  
   
..NEW ENGLAND
 
 
A FRONTAL WAVE FORMING ALONG A COLD FRONT DRAPED THROUGH SOUTHERN  
NEW ENGLAND WESTWARD THROUGH THE LOWER GREAT LAKES WILL HELP  
ENCOURAGE A MOIST, SOUTHERLY RETURN FLOW FROM THE ATLANTIC  
NORTHWARD THROUGH NEW ENGLAND DURING THE DAY FRIDAY. MULTIPLE  
SHORTWAVE PASSAGES AND A WARM CONVEYER BELT SETUP WILL LEAD TO  
MULTIPLE ROUNDS OF THUNDERSTORMS PRODUCING LOCALLY HEAVY RAINFALL.  
AN AXIS WITH A POTENTIALLY HIGHER THREAT WAS NOTED FROM THE EASTERN  
CATSKILLS/GREATER ALBANY NORTHEASTWARD THROUGH NORTHWESTERN  
MASSACHUSETTS, SOUTHERN VERMONT, AND CENTRAL NEW HAMPSHIRE,  
PARTICULARLY GIVEN THE SENSITIVITY OF THE MORE COMPLEX TERRAIN  
THROUGH THE REGION. HOWEVER, WITH THE LATEST HI-RES GUIDANCE STILL  
RELATIVELY LOCALIZED ON HIGHER TOTALS, HAVE HELD AT A MARGINAL RISK  
FOR NOW PENDING A CONFIRMATION/INCREASE IN POTENTIALLY MORE  
WIDESPREAD, HIGHER TOTALS.  
 
PUTNAM  
   
..PREVIOUS FORECAST
 
 
   
..OKLAHOMA INTO THE OK/KS/MO/AR BORDER AREA
 
 
ANOTHER ROUND OF SHORTWAVE ENERGY FORECAST TO DROP EAST  
SOUTHEASTWARD FROM THE CENTRAL ROCKIES INTO THE CENTRAL TO SOUTHERN  
PLAINS FRIDAY INTO FRIDAY NIGHT/EARLY SATURDAY. THIS WILL SUPPORT  
POTENTIAL FOR ANOTHER ROUND OF ORGANIZED CONVECTION IN THE VICINITY  
OF THE WEST TO EAST ORIENTED FRONTAL ZONE. 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 ACROSS MUCH  
OF OK INTO THE OK/KS/MO/AR BORDER REGION. ONLY SOME SLIGHT CHANGES  
TO THE PREVIOUS SLIGHT RISK AREA TO REFLECT THIS QPF AXIS  
CONSENSUS.  
   
..SOUTHERN GREAT BASIN INTO THE CENTRAL TO SOUTHERN ROCKIES
 
 
NOT A LOT OF CHANGES EXPECTED TO THE LARGE SCALE FLOW FROM DAY 1  
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. THE MARGINAL RISK  
WAS EXTENDED BACK ACROSS THESE AREAS TO BE MORE SIMILAR TO THE DAY  
1 PERIOD GIVEN THE SIMILAR OVERALL CONDITIONS DAY 2.  
   
..MID MS VALLEY, OH VALLEY INTO NEW ENGLAND
 
 
SIMILAR TO THE DAY 1 PERIOD, AN AXIS OF ABOVE AVERAGE PW VALUES  
WILL STRETCH ALONG THE SLOW MOVING FRONT STRETCHING FROM THE MID MS  
VALLEY, OH VALLEY INTO NEW ENGLAND. THERE IS GOOD MODEL CONSENSUS  
ON A BROAD REGION OF MODERATE TO LOCALLY HEAVY PRECIP AMOUNTS ALONG  
THIS FRONT. ONLY SOME MINOR CHANGES TO REFLECT THE LATEST MODEL  
QPF AXIS CONSENSUS MADE TO THE PREVIOUS BROAD MARGINAL RISK AREA  
ACROSS THESE REGIONS.  
 
ORAVEC  
 
DAY 3  
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...  
   
..2030Z UPDATE
 
 
THE PRIOR FORECAST REMAINS ON TRACK WITH RESPECT TO THE SOUTHERN  
PLAINS EASTWARD THROUGH THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS  
WITH ONLY MINOR AREAL ADJUSTMENTS BASED ON THE LATEST 12Z  
GUIDANCE. FURTHER NORTH, FORECAST RAINFALL TOTALS HAVE COME DOWN IN  
NEW ENGLAND, WITH GUIDANCE NOW SUGGESTIVE OF ONLY SOME RELATIVELY  
ISOLATED TOTALS AROUND 1". HAVE MAINTAINED A MARGINAL RISK FOR NOW  
BUT GIVEN THE LOWER TOTALS AND MORE PROGRESSIVE NATURE OF THE COLD  
FRONT SATURDAY, A THREAT FOR EVEN ISOLATED FLOODING MAY NOT  
ULTIMATELY MATERIALIZE AND WILL BE RE-EVALUATD IN SUBSEQUENT  
OUTLOOKS.  
 
PUTNAM  
   
..PREVIOUS FORECAST
 
 
THE SECOND ROUND OF HEIGHT FALLS MOVING INTO THE CENTRAL TO  
SOUTHERN PLAINS DAY 2 WILL CONTINUE TO PUSH EAST SOUTHEAST TOWARD  
THE MID TO LOWER MS VALLEY, OH AND TN VALLEYS. 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 PREVIOUS SLIGHT RISK AREA WAS EXPANDED EASTWARD  
CONSIDERABLY FROM EASTERN OK, ACROSS MUCH OF AR, WESTERN TN AND  
NORTHERN MS.  
   
..NORTHERN NEW ENGLAND
 
 
A SHARPENING NORTHERN STREAM TROF WILL PUSH SURFACE LOW PRESSURE  
ACROSS NORTHERN NEW ENGLAND ON SUNDAY. THERE IS FAIRLY GOOD MODEL  
CONSENSUS FOR MODERATE TO LOCALLY HEAVY PRECIP TOTALS ACROSS  
NORTHERN NEW ENGLAND. ONLY SOME SLIGHT CHANGES TO THE PREVIOUS  
MARGINAL RISK AREA, EXTENDING IT INTO ALL OF NORTHERN MAINE TO  
COVER THE MODEL QPF SPREAD.  
 
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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