088  
FXUS63 KLSX 081833  
AFDLSX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
133 PM CDT TUE JUL 8 2025  
   
KEY MESSAGES
 
 
- SCATTERED THUNDERSTORMS ARE EXPECTED TO TRACK SOUTHEAST THROUGH  
THE REGION TODAY. A FEW THUNDERSTORMS COULD BE STRONG, INCLUDING  
THE POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS WITH WINDS GUSTS  
TO 60 MPH AND LOCALLY HEAVY RAIN.  
 
- WARM, SEASONABLE TEMPERATURES WILL PERSIST THROUGH THE NEXT  
SEVERAL DAYS ALONG WITH PERIODIC CHANCES FOR THUNDERSTORMS  
IMPACT THE REGION.  
 

 
   
SHORT TERM
 
(THROUGH LATE WEDNESDAY NIGHT)  
ISSUED AT 130 PM CDT TUE JUL 8 2025  
 
THUNDERSTORM POTENTIAL WILL BE THE PRIMARY FOCUS THIS AFTERNOON  
INTO THIS EVENING AS AN UPPER LEVEL TROUGH AND MCV (MESOSCALE  
CONVECTIVE VORTEX) ROTATE SOUTHEASTWARD THROUGH LATE THIS EVENING.  
IR SATELLITE SHOWS A BROAD EXPANSE OF BROKEN/OVERCAST CLOUDS  
EXTENDING FROM NORTHERN MO THROUGH PORTIONS OF IA/IL/WI. CLOUDS  
ARE ASSOCIATED WITH THE MCV, REMNANT OF A CONVECTIVE COMPLEX THAT  
DEVELOPED OVER SD/NE LAST EVENING. ANOTHER AREA OF CLOUDS AND  
CONVECTION EXTEND FROM EASTERN OK INTO SOUTHERN IN. IN BETWEEN THE  
TWO AREAS, SKIES HAVE REMAINED MOSTLY CLEAR, ALLOWING INSTABILITY  
TO BUILD AHEAD OF THE APPROACHING MCV.  
 
AS OF 18Z, SPC MESOANALYSIS SHOWS A WHAT LITTLE CIN THAT EXISTS  
EXTENDING FROM KANSAS CITY ROUGHLY JUST WEST OF QUINCY, IL. WHERE  
SKIES HAVE REMAINED MOSTLY CLEAR, SURFACE INSTABILITY HAS CLIMBED  
WITH 2500 J/KG OF SBCAPE ROUGHLY ALONG AND NORTH OF THE I-44  
CORRIDOR INTO SOUTHWESTERN IL ALONG I-70. THIS NOT ONLY JIVES  
PRETTY WELL WITH GUIDANCE FROM PRIOR RUNS, INCLUDING THIS MORNING,  
AND MAYBE EVEN ON THE HIGHER END. HREF MEANS SHOWED SBCAPE OF  
2-2.2K WITH DETERMINISTIC HI-RESE GUIDANCE (RAP/HRRR) PLOTTING  
2.5-3K THIS AFTERNOON. MOISTURE IS NO QUESTION WITH DEWPOINTS IN  
THE UPPER 60S TO LOW-70S AND PWATS AROUND 1.7" PER SPC  
MESOANALYSIS. THUNDERSTORMS WILL CERTAINLY HAVE THE MOISTURE TO  
PRODUCE EFFICIENT RAINFALL WITH LOCALLY HEAVY RAIN, RESULTING IN  
PONDING/NUISANCE FLOOD IN AREAS IMPACTED BY MULTIPLE CELLS. THOUGH  
SOUNDINGS ARE SHOWING A PARTICULARLY CLASSIC INVERTED-V, 50-100MB  
DEWPOINT DEPRESSIONS IN THE REALM OF 10-13C SUGGEST LOCALIZED  
DOWNBURSTS WITH MARGINALLY SEVERE WIND GUSTS (60 MPH) ARE  
POSSIBLE. HAIL CANNOT BE ENTIRELY RULED OUT, BUT WHAT DOES FALL IS  
LIKELY SUB-SEVERE WITH MID-LEVEL LAPSE RATES AT 5.5-6C AND  
COMPETING UPDRAFTS AS SCATTERED CONVECTION BECOME MORE NUMEROUS  
IN TIME.  
 
DESPITE SOME SLIGHT SPATIAL/TEMPORAL VARIABILITY BETWEEN  
DETERMINISTIC HI-RES MODELS, PAINTBALL PLOTS (SIMULATED REFLECTIVITY  
>40 DBZ) SHOW A GENERAL CONSENSUS THAT THE BEST TIMEFRAME FOR  
DEVELOPMENT RUNS FROM NEAR KCOU TO JUST SOUTH OF KPPQ. IR SATELLITE  
IS SHOWING A NOTABLE UPTICK IN DEVELOPMENT IN THIS REGION,  
INCREASING CONFIDENCE THAT THIS WILL BE THE REGION FOR FOCUSED  
INITIATION. THUNDERSTORMS THEN MOVE SOUTHEAST THROUGH APPROXIMATELY  
8-9 P.M. AS THUNDERSTORMS PROGRESS SOUTHEAST AND WEAKEN AFTER  
SUNSET.  
 
ONCE THUNDERSTORMS CLEAR TO THE SOUTHEAST AND DISSIPATE LATE THIS  
EVENING, CLOUDS LIKELY HANG ON FOR SOME TIME TONIGHT BEFORE PARTIAL  
CLEARING WORKS INTO NORTHEAST MO. THERE IS SOME HINT AT PATCHY FOG  
DEVELOPMENT RUNNING FROM CENTRAL TO NORTHEAST MO, BUT CLOUD COVER  
MAY NOT CLEAR QUICK ENOUGH BEFORE SUNRISE, LIMITING FOG POTENTIAL.  
THIS WILL BE SOMETHING TO MONITOR THROUGH TONIGHT, BUT EVEN IF FOG  
DEVELOPS, IT IS NOT EXPECTED TO BE ANYTHING SIGNIFICANT WITH THE  
LIMITED TIME TO TAKE ADVANTAGE OF CLEARING.  
 
BY WEDNESDAY, MOSTLY DRY CONDITIONS ARE EXPECTED WITH THE LOW CHANCE  
THAT AN ISOLATED SHOWER MAY DEVELOP. HOWEVER, MUCH OF THE POTENTIAL  
WILL RESIDE OUTSIDE THE CWA. SHOULD ANYTHING DEVELOP, THE BEST  
CHANCE (30-40%) WILL LINE UP ALONG THE SOUTHEAST PORTION OF THE CWA  
WITH CHANCES QUICKLY TAPERING TO THE NORTH AND DROPPING THROUGH THE  
DAY AS SURFACE HIGH PRESSURE BUILDS IN FROM THE NORTHWEST.  
 
MAPLES  
 

 
   
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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)  
ISSUED AT 1232 PM CDT TUE JUL 8 2025  
 
THE PRIMARY FOCUS WILL BE THE POTENTIAL FOR SHOWERS AND  
THUNDERSTORMS THIS AFTERNOON INTO THIS EVENING, A FEW OF WHICH  
COULD BE STRONG TO MARGINALLY SEVERE. THE PRIMARY THREATS WILL BE  
LOCALLY HEAVY RAIN AND GUST WINDS, INCLUDING ISOLATED GUSTS  
APPROACHING 60 MPH IN THE STRONGEST THUNDERSTORMS. A FEW SHOWERS  
HAVE ALREADY DEVELOPED AROUND KUIN WITH POTENTIAL TRENDING  
SOUTHWARD AS MORE ROBUST CONVECTION INITIALIZED ACROSS CENTRAL AND  
EAST-CENTRAL MISSOURI INTO SOUTHWESTERN ILLINOIS. CONSIDERING THE  
SLIGHT DIFFERENCE IN HI-RESOULTION GUIDANCE AND SCATTERED NATURE  
OF CONVECTION, TEMPO GROUPS WERE UTILIZED TO CONVEY THE PERIOD OF  
GREATEST IMPACT. THIS MAY BE ADJUSTED IN LATER AMENDMENTS SHOULD  
INITIALIZATION OF ACTIVITY BE DEPARTED FROM CURRENT THOUGHTS. THE  
STRONGEST CELLS ARE LIKELY TO RESULT IN MVFR CEILINGS/VISIBILITY  
FOR BRIEF PERIODS.  
 
OUTSIDE OF THE THUNDERSTORM POTENTIAL, VFR CONDITIONS ARE  
EXPECTED. A FEW SHOWERS AND THUNDERSTORMS MAY LINGER INTO THIS  
EVENING, BUT GENERALLY SPEAKING, THUNDERSTORMS WILL MOVE SOUTH OF  
THE TERMINALS AND WEAKEN AFTER SUNSET. LIGHT/VARIABLE SURFACE  
WINDS WILL PERSIST INTO WEDNESDAY.  
 
MAPLES  
 

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

 
 

 
 
WFO LSX  
 
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