832  
FOUS30 KWBC 060800  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
400 AM EDT SAT JUN 6 2026  
 
DAY 1  
VALID 12Z SAT JUN 06 2026 - 12Z SUN JUN 07 2026  
 
...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF THE  
SOUTHERN PLAINS, OHIO VALLEY, UPPER TEXAS COAST, AND CENTRAL GULF  
COAST...  
   
..SOUTHERN PLAINS  
 
A PLUME OF DEEP TROPICAL MOISTURE WILL SURGE NORTHWARD ACROSS THE  
SOUTHERN PLAINS ON SATURDAY. THE LOW LEVEL JET ADVECTING THIS  
MOISTURE NORTH WILL RUN INTO AN AREA OF ENHANCED LIFT DUE TO A  
NEARBY UPPER LEVEL SHORTWAVE, WHICH WILL BE LIFTING NORTHEAST TO  
REJOIN THE JET. THE RESULT WILL BE A SERIES OF ROUNDS OF STORMS  
MOVING NORTH-NORTHEAST ACROSS PORTIONS OF NORTH TEXAS, EASTERN  
OKLAHOMA AND WESTERN ARKANSAS. HIGHLY EFFICIENT WARM RAIN PROCESSES  
WILL DOMINATE DUE TO THE PRESENT OF SUCH ABUNDANT AMOUNTS OF  
MOISTURE, WITH PWATS CLOSE TO 2 INCHES. FOR EASTERN  
OKLAHOMA/WESTERN ARKANSAS, THE RAIN WILL PERSIST FOR MUCH OF THE  
DAY IN THE FORM OF TRAINING LINES OF STORMS. BACK INTO TEXAS, THE  
THREAT WILL BE MOSTLY OVERNIGHT TONIGHT DUE TO PERSISTENT STORMS  
ASSOCIATED WITH AN MCS THAT WILL DRIFT EAST ACROSS FAR NORTH TEXAS  
AND SOUTHERN OKLAHOMA. AN INTERNAL HIGHER-END SLIGHT WAS INTRODUCED  
FROM SOUTHWEST OF THE METROPLEX THROUGH IT, AND CONTINUING INTO  
MUCH OF EASTERN OKLAHOMA AND WESTERN ARKANSAS FOR THE COMBINATION  
OF TWO AREAS OF PERSISTENT HEAVY RAIN. OVERALL CHANGES FROM  
INHERITED WERE MINIMAL.  
   
..OHIO VALLEY  
 
A VERY-SLOW MOVING COLD FRONT DRIFTING SOUTH ACROSS THE  
MIDWEST/OHIO VALLEY ON SATURDAY WILL BE THE ANIMUS FOR MULTIPLE  
ROUNDS OF STORMS WHICH WILL TRACK EAST-SOUTHEAST FROM INDIANA EAST  
TO THE CENTRAL APPALACHIANS. A NEW SLIGHT RISK AREA WAS INTRODUCED  
WITH THIS UPDATE. IN THE UPPER LEVELS, A SHORTWAVE MAY HELP THE  
STORMS BECOME STRONGER FOR THE FIRST PART OF THE PERIOD BEFORE  
SHIFTING OFF TO THE EAST. THE FRONT WILL FORM THE LEADING NOSE OF A  
PLUME OF DEEP GULF MOISTURE TRACKING NORTHWARD UP THE MISSISSIPPI  
VALLEY. THE FRONT WILL "SHEAR" THE MOISTURE EASTWARD IN A NARROW  
CORRIDOR, ALONG WHICH THE STORMS WILL FORM AND MOVE. STRONGER AND  
MORE PERSISTENT STORMS FROM INDIANA TO WESTERN OHIO WILL BECOME  
SOMEWHAT LESS STRONG AND LESS ORGANIZED INTO THE MOUNTAINS OF  
WESTERN PENNSYLVANIA AND WEST VIRGINIA, BUT THOSE AREAS WILL HAVE  
LOWER FFG THRESHOLDS, ALLOWING THE TWO AREAS TO COMBINE INTO ONE  
SLIGHT RISK AREA FOR SOMEWHAT DIFFERENT REASONS. UPLIFT ALONG THE  
WESTERN FACE OF THE APPALACHIANS MAY ALSO LOCALLY ENHANCE RAINFALL  
RATES.  
   
..UPPER TEXAS COAST  
 
IN COORDINATION WITH HGX/HOUSTON, TX FORECAST OFFICE, A SLIGHT RISK  
UPGRADE WAS INTRODUCED WITH THIS UPDATE. EXTREME AMOUNTS OF  
MOISTURE WILL BE IN PLACE THROUGHOUT THE ATMOSPHERE OF SOUTHEAST  
TEXAS SATURDAY AFTERNOON. PWATS BETWEEN 2 AND 2.25 INCHES ARE 3  
SIGMA ABOVE NORMAL FOR THIS TIME OF YEAR, AN IMPRESSIVE THRESHOLD  
TO MEET FOR JUNE. WITH PEAK HEATING THIS AFTERNOON, SCATTERED  
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO FORM, LIKELY 20-50 MILES  
INLAND FROM THE COAST. COLD POOLS FROM FRIDAY'S STORMS AND NEW ONES  
FROM THE STORMS THAT FORM SATURDAY AFTERNOON WILL LIKELY DRIVE NEW  
STORM DEVELOPMENT ALONG THE I-10 CORRIDOR FROM SOUTHWEST OF HOUSTON  
TO THE TX/LA BORDER NEAR BEAUMONT. WITH PLENTY OF NEW MOISTURE  
STREAMING NORTH OFF THE GULF, THE STORMS WILL HAVE NO TROUBLE  
REFORMING AND TRAINING OVER THE SAME AREAS FOR THE DURATION OF THE  
LONG AFTERNOON. NIGHTFALL SHOULD END THE STORMS IN THE AREA DUE TO  
LACK OF OTHER FORCING AND THE LOSS OF INSTABILITY. FRIDAY'S STORMS  
HAVE KNOCKED DOWN FFGS IN THIS REGION SIGNIFICANTLY, AND WITH GOOD  
CAPABILITY OF EFFICIENT WARM RAIN PROCESSES, URBAN CONCERNS IN  
HOUSTON, AND SLOW STORM MOVEMENT WERE ALL REASONS CONTRIBUTING TO  
THE SLIGHT RISK UPGRADE.  
   
..CENTRAL GULF COAST  
 
FEW CHANGES WERE NEEDED TO THE SLIGHT RISK AREA FROM NEW ORLEANS  
EAST TO PENSACOLA. A STRONG FRONT IS IN PLACE ACROSS THE EASTERN  
GULF, CHARACTERIZED BY VERY DRY AIR TO ITS EAST, RATHER THAN ANY  
SIGNIFICANT TEMPERATURE GRADIENT. THE DRY AIR IS 2 SIGMA BELOW  
NORMAL OVER PORTIONS OF CENTRAL FLORIDA...UNDER 1 INCH PWATS.  
MEANWHILE TO THE WEST FROM LOUISIANA THROUGH TEXAS, AN ABNORMALLY  
MOIST AIR MASS WILL BE STREAMING NORTH TO THE WEST OF THE HIGH  
PRESSURE AREA CHARACTERIZED BY THE DRY AIR. OVER MUCH OF LOUISIANA,  
PWATS WILL BE OVER 2.25 INCHES OR 3 SIGMA ABOVE NORMAL. THE FRONT  
MAKES UP THE GRADIENT BETWEEN THESE EXTREMELY CONTRASTING AIR  
MASSES. THROUGH THE DAY, THE FRONT WILL PUSH EAST AS THE MOIST AIR  
MASS GRADUALLY GAINS GROUND. HOWEVER, THE FRONT WILL BE THE FORCING  
ALONG WHICH NUMEROUS SHOWERS AND THUNDERSTORMS PUSHING NORTH OUT OF  
THE GULF WILL FORM ALONG. THE FRONT WILL BE SLOW TO MOVE, ALLOWING  
REPEATING ROUNDS OF STORMS TO IMPACT THE CENTRAL GULF COAST. FFGS  
ARE HIGH, ABOUT 4 INCHES/HOUR, BUT THE REPEATING ROUNDS OF STORMS  
SHOULD RATHER QUICKLY BRING THOSE NUMBERS DOWN, ALLOWING FOR WIDELY  
SCATTERED INSTANCES OF FLASH FLOODING TO DEVELOP WHERE THE RAINS  
ARE MOST PERSISTENT BY LATE AFTERNOON. NIGHTFALL SHOULD SEE A  
DECREASE IN SHOWER AND STORM ACTIVITY, ENDING THE FLOODING THREAT.  
 
WEGMAN  
 
DAY 2  
VALID 12Z SUN JUN 07 2026 - 12Z MON JUN 08 2026  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR MUCH OF THE  
MID-MISSISSIPPI VALLEY, OZARKS, AND THE WESTERN TENNESSEE  
VALLEY...  
 
A PAIR OF FORCINGS WILL WORK CAUSE RENEWED ROUNDS OF SHOWERS AND  
STORMS ACROSS MUCH OF THE MISSISSIPPI VALLEY ON SUNDAY INTO SUNDAY  
NIGHT. A SLOW MOVING BUT STILL POTENT UPPER LEVEL LOW WILL TRACK  
NORTHEASTWARD UP THE PLAINS AND INTO THE MIDWEST BY LATE SUNDAY  
NIGHT. MEANWHILE A STRONG FRONT ORIENTED NORTH-SOUTH WILL ALLOW FOR  
SHOWER AND THUNDERSTORM DEVELOPMENT FURTHER EAST ACROSS PORTIONS OF  
THE SOUTH. FOR THE MID-MISSISSIPPI VALLEY AND OZARKS, THE SHORTWAVE  
WILL BE THE PRIMARY FORCING. DEEP TROPICAL MOISTURE CHARACTERIZED  
BY PWATS ON EITHER SIDE OF 2 INCHES WILL ADVECT NORTHWARD UP THE  
MISSISSIPPI VALLEY. THE SHORTWAVE WILL PROVIDE THE FORCING FOR  
STORMS TO FORM, ALONG WITH THE TOPOGRAPHY OF THE OZARKS. MANY OF  
THESE AREAS, ESPECIALLY FROM FAR EASTERN OKLAHOMA, NORTHWESTERN  
ARKANSAS, AND SOUTHWEST MISSOURI HAVE SEEN REPEATED ROUNDS OF HEAVY  
RAIN IN RECENT DAYS, SO FFGS ARE LOWER IN THIS AREA. THUS, A  
HIGHER-END SLIGHT WAS INTRODUCED FOR THIS AREA DEPICTING AN EVEN  
GREATER THREAT FOR FLASH FLOODING, AS THE TOPOGRAPHY OF THE OZARKS  
WORKS TO INCREASE THE SEVERITY OF ANY FLOODING. FFGS ARE ALSO LOWER  
FROM NORTHERN MISSOURI INTO IOWA. STORMS FORMING IN THESE AREAS  
WILL BE CLOSER TO THE NOSE OF THE LOW LEVEL JET, THOUGH THE UPPER  
LEVEL SHORTWAVE SHOULD STILL BE THE PRIMARY FORCING.  
 
THE SLIGHT RISK AREA WAS EXPANDED NORTH UP THE MISSISSIPPI VALLEY  
INTO SOUTHERN AND EASTERN IOWA AND WESTERN ILLINOIS WITH THIS  
UPDATE.  
 
FOR PORTIONS OF THE WESTERN TENNESSEE VALLEY, INCLUDING WESTERN  
TENNESSEE FAR NORTHEASTERN MISSISSIPPI, AND ESPECIALLY NORTHERN  
ALABAMA, THE AFOREMENTIONED NORTH-SOUTH ORIENTED FRONT WILL BE THE  
PRIMARY FORCING FOR THE FIRST HALF OF THE DAY. THE FRONT WILL MORE  
RAPIDLY RETREAT EAST ACROSS GEORGIA BY SUNDAY NIGHT, LEAVING ANY  
FORCING TO WEAK UPPER LEVEL SHORTWAVES. THUS, MOST OF THE STORMS  
WILL BE DURING THE AFTERNOON AND EVENING DURING PEAK HEATING AND  
WHEN THE FRONT IS CLOSER. FFGS ARE LOWER ACROSS NORTHERN ALABAMA  
FROM RECENT HEAVY RAINFALL, AROUND 2.5 IN/HOUR, WHICH DUE TO PWATS  
OCCASIONALLY OVER 2 INCHES, SHOULD BE EASILY ATTAINABLE BY THE  
STRONGEST STORMS EXPECTED SUNDAY AFTERNOON. THUS, THE SLIGHT RISK  
WAS EXPANDED SOUTHEAST FOR THESE REASONS.  
 
WEGMAN  
 
DAY 3  
VALID 12Z MON JUN 08 2026 - 12Z TUE JUN 09 2026  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE  
MID-MISSISSIPPI, LOWER OHIO, AND WESTERN TENNESSEE VALLEYS...  
 
ON MONDAY, THE EXCESSIVE RAINFALL RISK TRANSLATES A BIT FURTHER  
NORTH AND EAST INTO THE MID-MISSISSIPPI, LOWER OHIO, AND WESTERN  
TENNESSEE VALLEYS. A STRONG FRONT OVER THE GREAT LAKES WILL RETREAT  
NORTHEASTWARD AS THE PLUME OF ANOMALOUSLY DEEP MOISTURE FROM THE  
GULF SURGES NORTHEASTWARD TO REPLACE THE DRIER AIR MASS IN PLACE  
OVER THE NORTHEAST. A SLOW-MOVING NEGATIVELY TILTED TROUGH WILL  
ALSO PROMOTE UPPER DIVERGENCE AND LIFT THROUGHOUT THE ATMOSPHERE  
OVER THE SLIGHT RISK AREA THROUGHOUT THE PERIOD. PWATS AROUND 2  
INCHES WILL BE 3 SIGMA ABOVE NORMAL FOR THIS TIME OF YEAR ACROSS  
THE REGION, SO MANY OF THE STORMS THAT FORM WILL CONSIST OF HIGHLY  
EFFICIENT WARM RAIN PROCESSES, WHICH WILL PROMOTE HEAVY RAINFALL.  
FFGS ACROSS THE REGION WILL AVERAGE AROUND 2-2.5 INCHES, WHICH WILL  
BE EASILY OVERCOME BY MANY OF THE STRONGEST CELLS, SO LONG AS THEIR  
FORWARD SPEED IS KEPT IN CHECK. THE SLIGHT RISK AREA WAS NUDGED  
WEST OVER MORE OF SOUTHEASTERN MISSOURI WITH THIS UPDATE, ADJUSTED  
FOR EXPECTED HEAVY RAINFALL AND LIKELY LOWER FFGS IN THIS REGION  
FROM THE DAY 2/SUNDAY PERIOD.  
 
WEGMAN  
 
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  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab HPC Page
Main Text Page