561  
FXUS63 KLSX 090920  
AFDLSX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
420 AM CDT WED JUL 9 2025  
   
KEY MESSAGES  
 
- SEASONABLY WARM TEMPERATURES ARE EXPECTED INTO THE WEEKEND WITH  
THE WARMEST DAY ON FRIDAY.  
 
- AFTER A MAINLY DRY DAY TODAY, THE CHANCE FOR SHOWERS AND  
THUNDERSTORMS WILL INCREASE OVER THE WEEKEND.  
 
 
   
SHORT TERM  
(THROUGH LATE THURSDAY AFTERNOON)  
ISSUED AT 418 AM CDT WED JUL 9 2025  
 
LATEST SURFACE ANALYSIS IS SHOWING HIGH PRESSURE CENTERED OVER  
NORTHERN MISSOURI WITH A STATIONARY FRONT EXTENDING FROM THE GREAT  
LAKES INTO THE NORTHERN PLAINS. THE HIGH CLOUDS WERE IN THE PROCESS  
OF CLEARING OUT OVER THE AREA REVEALING VALLEY FOG IN THE NIGHTTIME  
MICROPHYSICS CHANNEL. EXPECT THIS FOG TO STICK AROUND THROUGH MID  
MORNING BEFORE IT WILL DISSIPATES. THEN EXPECT A MAINLY DRY DAY AS  
THE HREF IS SHOWING THE UPPER TROUGH SLOWING MOVING OFF TO THE EAST  
WITH FORECAST SOUNDINGS MAINLY CAPPED OVER THE AREA TODAY. THE HREF  
MEMBERS ARE MAINLY DRY INTO TONIGHT BEFORE SOME MEMBERS SHOW A MCS  
DEVELOPING OVER EASTERN NEBRASKA/WEST IOWA LATE TONIGHT ON THE NOSE  
OF A NOCTURNAL LOW LEVEL JET. THIS MCS WILL EVENTUALLY MOVE ALONG  
THE FRONT AND INTO NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS BY  
TOMORROW MORNING. THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL  
LINGER ALONG THE FRONT OVER THE NORTHERN HALF OF THE CWA INTO  
THURSDAY AFTERNOON WHERE MLCAPES WILL BE IN THE 1500-3000 J/KG. DEEP  
LAYER SHEAR WILL ONLY BE IN THE 15-30 KNOT RANGE LIMITING THE SEVERE  
WEATHER THREAT.  
 
HIGH TEMPERATURES THE NEXT TWO DAYS WILL BE SEASONABLY WARM IN THE  
MIDDLE 80S TO AROUND 90 DEGREES AS 850 MB TEMPERATURES ARE IN THE 15-  
20C RANGE.  
 
BRITT  
 
 
   
LONG TERM  
(THURSDAY NIGHT THROUGH TUESDAY)  
ISSUED AT 418 AM CDT WED JUL 9 2025  
 
THE UPPER PATTERN FROM LATE THIS WEEK INTO EARLY NEXT WEEK WILL  
CONTINUE TO HAVE MISSOURI AND ILLINOIS SITTING ON THE SOUTHERN EDGE  
OF THE ACTIVE WESTERLIES WITH LARGE HIGHS OVER THE SOUTHERN CONUS.  
THE GLOBAL MODELS ARE HIGHLIGHTING A SERIES OF TROUGHS MOVING  
THROUGH THE UPPER FLOW WITH THE MOST LREF MEMBERS PRODUCING RAIN  
FRIDAY NIGHT INTO SATURDAY AND AGAIN ON TUESDAY. WHILE IT WILL NOT  
BE RAINING ALL OF THE TIME, MODEL PWATS AOA 2" SUGGEST THE POTENTIAL  
FOR SOME LOCALLY HEAVY RAINFALL OVER THE WEEKEND.  
 
THE WARMEST DAY STILL LOOKS TO BE FRIDAY WITH HIGHS IN THE LOW TO  
MID 90S AND HEAT INDEXES AROUND 100 DEGREES. TEMPERATURES THROUGH  
THE WEEKEND INTO NEXT WEEK LOOK CLOSE TO JULY NORMALS RANGING FROM  
THE MID 80S TO AROUND 90 DEGREES.  
 
BRITT  
 
 
   
AVIATION  
(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)  
ISSUED AT 932 PM CDT TUE JUL 8 2025  
 
THE MAIN CONCERN FOR OVERNIGHT IS FOG POTENTIAL. CONTINUE TO THINK  
THAT THE BEST CHANCES ARE IN CENTRAL MISSOURI AS BOTH KCOU/KJEF  
DID RECEIVE SOME RAIN AND AT LEAST SOME PARTIAL CLEARING IS LIKELY  
OVERNIGHT. IFR VISIBILITIES ARE EXPECTED AT BOTH OF THESE  
TERMINALS LATE TONIGHT INTO EARLY WEDNESDAY MORNING. ELSEWHERE,  
THE FOG POTENTIAL IS A LOWER DUE TO LINGERING CLOUD COVER. KSUS  
MAY AT LEAST HAVE A BRIEF PERIOD OF MVFR VISIBILITES AS SOME LATE  
PARTIAL CLEARING IS EXPECTED BEFORE DAYBREAK.  
 
ANY FOG SHOULD QUICKLY LIFT/DISSIPATE BY 1300 UTC, WITH DRY/VFR  
CONDITIONS AND LIGHT/VARIABLE WINDS EXPECTED THROUGH WEDNESDAY  
EVENING. CANNOT COMPLETELY RULE OUT A ROGUE SHOWER/WEAK  
THUNDERSTORM ON WEDNESDAY AFTERNOON, BUT THE COVERAGE CONTINUES TO  
LOOK MUCH TOO LOW TO ADD ANY VC OR PROB30 MENTION TO ANY OF THE  
TERMINALS AT THIS JUNCTURE.  
 
GOSSELIN  
 
 
   
LSX WATCHES/WARNINGS/ADVISORIES  
 
MO...NONE.  
IL...NONE.  
 
 
 
 
WFO LSX  
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