305  
FXUS63 KLSX 081053  
AFDLSX  
 
AREA FORECAST DISCUSSION...UPDATED AVIATION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
553 AM CDT TUE JUL 8 2025  
   
KEY MESSAGES
 
 
- THERE IS A CHANCE (30-60%) OF SHOWERS AND THUNDERSTORMS TODAY.  
ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE CAPABLE OF PRODUCING  
DAMAGING WIND GUSTS TO 60 MPH AND A LOCALIZED THREAT FOR HEAVY  
RAINFALL.  
 
- THERE WILL BE ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH  
THE WEEKEND WITH THE BEST CHANCE (40-60%) ON FRIDAY NIGHT AND  
SATURDAY.  
 

 
   
SHORT TERM
 
(THROUGH LATE WEDNESDAY AFTERNOON)  
ISSUED AT 336 AM CDT TUE JUL 8 2025  
 
AN MCS CURRENTLY OVER NORTHWEST MISSOURI IS EXPECTED TO CONTINUE TO  
MOVE EAST AND SOUTHEAST AND WEAKEN EARLY THIS MORNING AS THEY MOVE  
INTO AN ENVIRONMENT THAT IS INCREASINGLY STABLE OVER EASTERN MO.  
THIS IS REFLECTED IN THE LATEST CAMS RUNS WHICH SHOW THIS LINE  
DIMINISHING BEFORE THUNDERSTORMS REGENERATE OVER THE CWA THIS  
AFTERNOON. THIS WILL OCCUR AS AN UPPER TROUGH CURRENTLY OVER THE  
MIDDLE MISSOURI VALLEY WILL DROPS SOUTHEAST INTO THE MISSOURI AND  
ILLINOIS LATER TODAY. THE OUTFLOW AND POTENTIALLY AN MCV FROM THE  
REMNANT MCS MAY ALSO AID IN THE REDEVELOPMENT OF THUNDERSTORMS THIS  
AFTERNOON. WHILE MLCAPES WILL BE IN THE 1500-2500 J/KG RANGE, DEEP  
LAYER SHEAR WILL ONLY BE IN THE 20-30 KNOT RANGE WITH MOST OF THE  
SHEAR IN THE LOWER PART OF THE HODOGRAPH. FORECAST SOUNDINGS DO  
SUPPORT THE POTENTIAL FOR ISOLATED DAMAGING WINDS TO 60 MPH PER THE  
SPC MARGINAL RISK. IN ADDITION, PWATS WILL BE IN 1.75 TO 2.0"  
RANGE, SO ANY SLOW MOVING THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY  
RAINFALL. IT STILL APPEARS THE MOST LIKELY TIME FOR ANY SEVERE  
WEATHER OR HEAVY RAINFALL WILL BE BETWEEN 2 AND 8 PM.  
 
THE RAIN CHANCES WILL DIMINISH TONIGHT WITH THE LOSS OF DAYTIME  
HEATING. THE SOUTHERN END OF THE UPPER TROUGH WILL LINGER OVER THE  
MIDDLE MISSISSIPPI VALLEY ON WEDNESDAY BRINGING ADDITIONAL CHANCES  
(20-40%) OF SHOWERS AND THUNDERSTORMS OVER THE SOUTHEAST HALF OF THE  
CWA ON WEDNESDAY AFTERNOON. HIGH TEMPERATURES THE NEXT TWO DAYS  
WILL BE SEASONABLY WARM IN THE 85 TO 90 DEGREE RANGE AS 850 MB  
TEMPERATURES ARE IN THE 15-20C RANGE.  
 
BRITT  
 

 
   
LONG TERM
 
(WEDNESDAY NIGHT THROUGH MONDAY)  
ISSUED AT 336 AM CDT TUE JUL 8 2025  
 
THE LREF IS SHOWING THAT THE UPPER PATTERN FROM MID WEEK INTO EARLY  
NEXT WEEK WILL BE HIGHLIGHTED BY A LARGE HIGH OVER THE SOUTHWEST  
CONUS WITH MISSOURI AND ILLINOIS ON THE SOUTHERN EDGE OF THE ACTIVE  
WESTERLIES. WHILE THERE WILL BE ON AND OFF CHANCE OF SHOWERS AND  
THUNDERSTORMS OVER THE MIDWEST AS TROUGHS MOVE THROUGH THE  
AFOREMENTIONED WESTERLIES, THE BEST CHANCE (40-60%) OVER OUR AREA  
WILL BE FRIDAY NIGHT INTO SATURDAY WHEN THERE IS GOOD AGREEMENT IN  
THE GLOBAL MODELS THAT A UPPER TROUGH AND ATTENDANT COLD FRONT WILL  
MOVE ACROSS MISSOURI AND ILLINOIS. WHILE THE WEEKEND DOES NOT LOOK  
LIKE A WASHOUT, I CAN'T RULE OUT HEAVY DOWNPOURS WITH SOME OF THE  
THUNDERSTORMS GIVEN PWATS AROUND 2".  
 
TEMPERATURES THROUGH THE PERIOD WILL BE CLOSE TO JULY NORMALS  
RANGING FROM THE MID 80S TO AROUND 90 DEGREES. THE NBM IS SHOWING  
THE WARMEST DAY ON FRIDAY WHEN MOST AREAS WILL SEE HIGHS IN THE LOW  
90S AND HEAT INDEXES NEAR 100 DEGREES AHEAD OF THE FRONT.  
 
BRITT  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)  
ISSUED AT 544 AM CDT TUE JUL 8 2025  
 
AN AREA OF WEAKENING SHOWERS AND ISOLATED THUNDERSTORMS WILL  
AFFECT UIN/COU/JEF THROUGH 15Z. ADDITIONAL SHOWERS AND  
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND AFFECT ALL OF THE  
TERMINALS BETWEEN 18-24Z. ANY OF THE HEAVIER SHOWERS AND  
THUNDERSTORMS WILL BE CAPABLE OF REDUCING CEILINGS AND  
VISIBILITIES TO MVFR OR POSSIBLY IFR CONDITIONS IN BRIEF HEAVY  
RAIN. THERE WILL ALSO BE THE POTENTIAL FOR WIND GUSTS OVER 35  
KNOTS WITH STRONGER THUNDERSTORMS THIS AFTERNOON. WINDS WILL  
REMAIN BELOW 10 KNOTS THROUGH THE PERIOD OUTSIDE OF THUNDERSTORMS.  
 
BRITT  
 

 
   
LSX WATCHES/WARNINGS/ADVISORIES
 
 
MO...NONE.  
IL...NONE.  

 
 

 
 
WFO LSX  
 
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