492  
FOUS30 KWBC 081600  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1200 PM EDT FRI MAY 8 2026  
 
DAY 1  
VALID 16Z FRI MAY 08 2026 - 12Z SAT MAY 09 2026  
 
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF  
SOUTHEASTERN LOUISIANA AND SOUTHERN MISSISSIPPI...  
   
..16Z UPDATE  
 
THE OVERNIGHT SLIGHT RISK AREA WAS MAINTAINED AS AN AREA OF  
TRAINING SHOWERS AND THUNDERSTORMS TAKE SHAPE ACROSS LOUISIANA AND  
MISSISSIPPI. 12Z HREF AND RRFS EAS NEIGHBORHOOD PROBABILITIES  
CONTINUE TO DEPICT A HIGH PROBABILITY OF RAINFALL EXCEEDING 2  
INCHES IN THE HIGHLIGHTED AREA. THIS ALIGNS WITH THE LOCATION OF  
AN INSTABILITY GRADIENT/STATIONARY FRONT ANALYZED NEAR THE GULF  
COAST WHICH WILL FOCUS CONVECTION TODAY.  
 
OTHERWISE, THE FORECAST IN SOUTH TEXAS REMAINS SOMEWHAT UNCERATIN,  
WITH SOME 12Z CAM GUIDANCE TRENDING MORE DRY IN THE AREA. HOWEVER,  
BASED OFF OF THE SYNOPTIC SETUP AND MOISTURE PROFILES OUTLINED  
PREVIOUSLY, THUNDERSTORM CLUSTERS CAPABLE OF PRODUCING ISOLATED  
FLASH FLOODING CERTAINLY REMAIN PLAUSIBLE. THUS, THE MARGINAL RISK  
WAS KEPT IN FOR THIS UPDATE.  
 
ASHERMAN  
   
..PREVIOUS DISCUSSION  
 
   
..LOWER MISSISSIPPI VALLEY/CENTRAL GULF COAST  
 
A ROBUST MOISTURE POOL IS EXPECTED TO DEEPEN ALONG THE CENTRAL  
GULF COAST TODAY AS SOUTHWESTERLY WINDS AMPLIFY AHEAD OF ENERGY  
MOVING OUT OF EASTERN TEXAS AND THE NORTHWESTERN GULF. THIS FLOW  
WILL SUPPORT PWS CLIMBING TO AROUND 2 INCHES ALONG A SLOW-MOVING  
FRONT, OR MORE THAN 2.5 STD DEV ABOVE NORMAL. THE MAJORITY OF THE  
CAMS ARE IN GOOD AGREEMENT INDICATING A CORRIDOR OF TRAINING  
CONVECTION DEVELOPING BY THE AFTERNOON ACROSS SOUTHEASTERN  
LOUISIANA AND SOUTHERN MISSISSIPPI. GIVEN THE HIGH MOISTURE CONTENT  
AND POTENTIAL FOR TRAINING, LOCALIZED TOTALS OF 2-3+ INCHES ARE  
POSSIBLE. HIGH HOURLY RATES WITHIN THESE TRAINING STORMS WILL POSE  
A RISK FOR FLASH FLOODING, PARTICULARLY IN LOW-LYING AND URBAN  
AREAS, WITH THE HIGHEST POTENTIAL IMPACT CENTERED ALONG THE I-10  
CORRIDOR. THE INTRODUCED SLIGHT RISK AREA REFLECTS HIGH  
NEIGHBORHOOD PROBABILITIES SHOWN BY BOTH THE HREF AND RRFS FOR  
AMOUNTS EXCEEDING 2 INCHES.  
   
..SOUTH TEXAS  
 
FARTHER WEST, A WELL-DEFINED MID-TO-UPPER LEVEL SHORTWAVE/LOW  
MOVING THROUGH NORTHERN MEXICO INTO WEST TEXAS WILL PROVIDE  
INCREASING ASCENT. MOIST SOUTHERLY FLOW INTERACTING WITH THIS  
FEATURE AND UPSLOPE INTO THE SIERRA MADRE ORIENTAL WILL SUPPORT  
STORMS DEVELOPING OVER NORTHEASTERN MEXICO. WHILE MUCH OF THIS  
ACTIVITY MAY REMAIN SOUTH OF THE INTERNATIONAL BORDER, THERE ARE  
SOME HI-RES MEMBERS THAT SHOW SOME OF THESE CONVECTIVE CLUSTERS  
MOVING INTO SOUTH TEXAS. THOUGH MODEL SPREAD IS HIGHER IN THIS  
REGION, BOTH THE HREF AND RRFS INDICATE THAT LOCALIZED TOTALS  
EXCEEDING 2 INCHES ARE POSSIBLE. THEREFORE, A MARGINAL RISK WAS  
MAINTAINED TO ACCOUNT FOR THIS POTENTIAL.  
 
PEREIRA  
 
DAY 2  
VALID 12Z SAT MAY 09 2026 - 12Z SUN MAY 10 2026  
 
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM THE CENTRAL  
GULF COAST INTO THE SOUTHEAST...  
 
THE PREVIOUSLY NOTED SHORTWAVE MOVING INTO WEST TEXAS ON DAY 1 IS  
FORECAST TO MOVE EASTWARD ALONG THE CENTRAL GULF COAST ON SATURDAY.  
WHILE LINGERING DEEP MOISTURE WILL REMAIN IN PLACE, THE SYNOPTIC  
SIGNAL FOR ORGANIZED AND WIDESPREAD HEAVY RAINFALL BECOMES  
SIGNIFICANTLY MORE DIFFUSE. CURRENT MODEL GUIDANCE LACKS A  
CONCENTRATED SIGNAL FOR HIGH-END TOTALS, SUGGESTING A MORE ISOLATED  
OR LOW-END FLASH FLOOD THREAT. GIVEN THE ENVIRONMENT AND THE  
POTENTIAL FOR ANTECEDENT CONDITIONS DRIVEN THE PREVIOUS DAY'S HEAVY  
RAINS, THE CURRENT MARGINAL RISK WAS MAINTAINED FOR THIS CYCLE. BUT  
SHOULD MODEL TRENDS CONTINUE TO SHOW A LACK OF ORGANIZATION, THIS  
AREA MAY BE DISCONTINUED IN FUTURE UPDATES.  
 
PEREIRA  
 
DAY 3  
VALID 12Z SUN MAY 10 2026 - 12Z MON MAY 11 2026  
 
...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL ACROSS PORTIONS  
OF NORTHEASTERN TEXAS, SOUTHEASTERN OKLAHOMA, SOUTHERN ARKANSAS,  
AND NORTHERN LOUISIANA...  
 
SHORTWAVE ENERGY DIVING INTO THE BASE OF BROADER SCALE TROUGH WILL  
DRIVE A COLD FRONT SOUTHWARD ACROSS THE REGION. SOUTHERLY FLOW  
AHEAD OF THE BOUNDARY WILL BOOST PWS TO OVER 1.5 INCHES. THIS  
MOISTURE, COMBINED WITH FAVORABLE UPPER JET FORCING, WILL SUPPORT  
STORMS DEVELOPING ALONG AND AHEAD OF THE FRONT. WHILE MODEL SPREAD  
IS CURRENTLY TOO HIGH TO SUPPORT A HIGHER RISK AREA AND THE SIGNAL  
FOR WIDESPREAD HEAVY TOTALS REMAINS MUTED, LOCALLY INTENSE RATES  
ALONG WITH SOME AREAS OF REPEATING CELLS COULD RESULT IN ISOLATED  
FLASH FLOODING.  
 
PEREIRA  
 
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