040  
FXUS63 KLSX 302047  
AFDLSX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
347 PM CDT SUN MAR 30 2025  
   
KEY MESSAGES
 
 
- THUNDERSTORMS, SOME SEVERE, WILL BE LIKELY BEFORE MOVING OUT OF  
THE AREA BY EARLY THIS EVENING. LARGE HAIL OF UP TO TWO INCHES IN  
DIAMETER, DAMAGING WINDS, AND A FEW TORNADOES REMAIN THE SEVERE  
WEATHER THREATS.  
 
- STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ON TUESDAY NIGHT AND  
AGAIN ON WEDNESDAY, MAINLY IN THE AFTERNOON AND EVENING.  
 

 
   
SHORT TERM
 
(THROUGH LATE MONDAY NIGHT)  
ISSUED AT 345 PM CDT SUN MAR 30 2025  
 
SEVERE THUNDERSTORMS CONTINUE TO PRODUCE HAIL UP TO GOLFBALL SIZE AS  
THEY MOVE ACROSS SOUTHEAST MISSOURI AND SOUTHWEST ILLINOIS THIS  
AFTERNOON. STILL CANNOT RULE OUT A FEW LARGER HAILSTONES AND A  
TORNADO OR TWO WITH THE SUPERCELLS OR WIND GUSTS TO 70 MPH WITH ANY  
BOWING SEGMENTS BEFORE THESE STORMS MOVE OUT OF THE AREA BY 7-8 PM  
WITH THE COLD FRONT. THEN EXPECT MAINLY DRY WEATHER THE REST OF  
TONIGHT THROUGH MONDAY NIGHT AS A DEEP RIDGE WILL MOVE INTO THE AREA  
AS THE HREF IS SHOWING HIGH PROBABILITIES OF STAYING DRY.  
 
IT WILL BE MUCH COOLER STARTING TONIGHT WITH LOWS TONIGHT AND MONDAY  
NIGHT MAINLY IN THE 30S AND HIGHS ON MONDAY ONLY IN THE 50S.  
CONFIDENCE IN THESE TEMPERATURES IS PRETTY HIGH AS THE NBM IQR IS  
ONLY 3-5 DEGREES AT ST. LOUIS.  
 
BRITT  
 

 
   
LONG TERM
 
(TUESDAY THROUGH NEXT SUNDAY)  
ISSUED AT 345 PM CDT SUN MAR 30 2025  
 
DRY WEATHER IS STILL ANTICIPATED ON TUESDAY BEFORE WE SEE AN  
INCREASE IN SHOWERS AND THUNDERSTORMS ON TUESDAY NIGHT, PARTICULARLY  
NORTH OF I-70 WHERE THERE WILL BE STRONG MOISTURE CONVERGENCE ON THE  
NOSE OF AN OVERNIGHT LOW LEVEL JET. STEEP LAPSE RATES COUPLED WITH  
STRONG MOISTURE TRANSPORT AHEAD OF A INCOMING UPPER TROUGH WILL LEAD  
TO FAVORABLE MUCAPES FOR LARGE HAIL LATE TUESDAY NIGHT OVER PARTS OF  
NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS PER THE LATEST SPC  
SWODY3.  
 
LATEST CLUSTER ANALYSIS IS IN BETTER AGREEMENT IN KEEPING THE NEXT  
UPPER LOW TO THE NORTH OF THE AREA ON WEDNESDAY ALONG WITH THE  
TIMING OF THE FRONT. THE LREF/GFS/ECMWF ARE SHOWING A LARGE  
UNSTABLE WARM SECTOR AHEAD OF THE FRONT WITH DEEP LAYER SHEAR  
FAVORING STRONG TO SEVERE THUNDERSTORMS. IT IS UNCLEAR AT THIS  
POINT HOW MUCH FORCING WILL BE AVAILABLE FOR THE STORMS TO FORM WITH  
THE UPPER LOW PASSING SO FAR TO THE NORTH OF THE AREA AND WHAT THE  
STORM MODE WILL ULTIMATELY WILL BE. THE POTENTIAL FOR SHOWERS AND  
A FEW THUNDERSTORMS WILL NOT CLEAR OUT LATE WEEK INTO NEXT WEEKEND  
AS THE UPPER PATTERN WILL TURN WEST-SOUTHWESTERLY BEHIND THE UPPER  
TROUGH. THIS WILL CAUSE THE ATTENDANT COLD FRONT TO HOLD UP JUST  
SOUTH OF THE CWA KEEPING A CHANCE (30-80%) OF ADDITIONAL SHOWERS AND  
THUNDERSTORMS WITH THE HIGHEST CHANCES IN SOUTHEAST MISSOURI.  
 
BRITT  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)  
ISSUED AT 1248 PM CDT SUN MAR 30 2025  
 
HAVE KEPT A TEMPO GROUP FOR SHOWERS AND THUNDERSTORMS IN THE ST.  
LOUIS METRO TERMINALS THROUGH 19Z. ANY OF THE HEAVIER SHOWERS OR  
THUNDERSTORMS COULD PRODUCE IFR CEILINGS AND VISIBILITIES ALONG  
WITH HAIL AND WIND GUSTS OVER 35 KNOTS. THEN MAINLY DRY WEATHER IS  
EXPECTED THE REST OF THE PERIOD WITH MVFR CEILINGS AT UIN/JEF/COU  
THROUGH 14-16Z BEFORE IMPROVING TO VFR. THERE WILL ALSO BE A  
PERIOD OF VFR CONDITION AT THE ST. LOUIS AREA TERMINALS THIS  
AFTERNOON BEFORE MVFR CEILINGS MOVE INTO THAT AIRPORTS TONIGHT.  
WESTERLY WINDS WITH GUSTS TO 25 KNOTS WILL TURN TO THE NORTHWEST  
TONIGHT.  
 
BRITT  
 

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

 
 

 
 
WFO LSX  
 
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