056  
FXUS63 KLSX 070341  
AFDLSX  
 
AREA FORECAST DISCUSSION...UPDATED AVIATION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
1041 PM CDT SUN JUL 6 2025  
   
KEY MESSAGES
 
 
- SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE EXPECTED  
THE REST OF THE AFTERNOON AND INTO THE EVENING. WHILE MOST WILL  
NOT BE STRONG OR SEVERE, OCCASIONAL STRONG DOWNBURST WINDS AND  
BURSTS OF HEAVY RAIN WILL BE POSSIBLE.  
 
- SCATTERED SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE (20-40%)  
ACROSS THE OZARKS AND SOUTHWEST ILLINOIS TOMORROW, BUT BETTER  
CHANCES (30-60%) EXIST AREA-WIDE TUESDAY.  
 
- SEASONABLY WARM TEMPERATURES WITH MODERATE TO HIGH HUMIDITY CAN  
BE EXPECTED FOR THE FORESEEABLE FUTURE.  
 

 
   
SHORT TERM
 
(THROUGH LATE MONDAY NIGHT)  
ISSUED AT 202 PM CDT SUN JUL 6 2025  
 
THE PRIMARY CONCERN FOR THIS AFTERNOON REMAINS THE POTENTIAL FOR  
SCATTERED THUNDERSTORMS, WHICH WILL HAVE THE POTENTIAL TO PRODUCE  
BURSTS OF HEAVY RAIN AND ISOLATED STRONG DOWNBURST WINDS.  
 
AS OF 1:00 PM, A WEAK COLD FRONT HAS MOVED INTO NORTHERN MISSOURI,  
AND CONTINUES TO INCH SOUTHWARD LATE THIS MORNING. ALONG AND SOUTH  
OF THIS BOUNDARY, MODERATE INSTABILITY IS SLOWLY BUILDING AS WE  
APPROACH MIDDAY, WITH AROUND 2000 J/KG OF MLCAPE ALREADY PRESENT PER  
SPC (RUC) MESOANALYSIS AND THE POTENTIAL TO REACH 2500 J/KG BY PEAK  
HEATING. MEANWHILE, LOW LEVEL LAPSE RATES ARE EXPECTED TO BE  
MODERATE TO STEEP BY PEAK HEATING (7.5 TO 8.5 C/KM), WITH MODERATE  
DOWNDRAFT CAPE (800-1000 J/KG) ALSO PROJECTED. EFFECTIVE WIND SHEAR  
IS EXPECTED TO REMAIN GENERALLY WEAK, WITH DEEP SOUTHWESTERLY FLOW  
OF ONLY AROUND 10 TO 20 KT AT ALMOST ALL LEVELS, AND THIS WILL  
LIKELY LIMIT THE ABILITY OF STORMS TO ORGANIZE AND FOR INDIVIDUAL  
UPDRAFTS TO PERSIST.  
 
MEANWHILE, LATEST HIGH RESOLUTION MODELS CONTINUE TO DEVELOP  
SCATTERED TO NUMEROUS THUNDERSTORMS ALONG AND SOUTH THE SLOWLY  
ADVANCING FRONT BY MID AFTERNOON, CONTINUING INTO THE EARLY EVENING  
BEFORE COVERAGE DIMINISHES AFTER SUNSET. WE'VE ALREADY SEEN THE  
EARLY STAGES OF THIS DEVELOPMENT, AND COVERAGE IS LIKELY TO CONTINUE  
TO INCREASE OVER THE NEXT FEW HOURS. WHILE FORCING IS WEAK, THERE IS  
AT LEAST SOME MODEST CONVERGENCE ALONG THE FRONT, AND ALSO PERHAPS A  
BIT OF UPPER SUPPORT FROM A VERY WEAK MID LEVEL TROUGH EVIDENT ON  
WATER VAPOR IMAGERY. NOT ONLY THIS, BUT SEVERAL CONSECUTIVE RUNS OF  
THE HRRR CONSISTENTLY FORECAST 30 TO 60 MPH CONVECTIVE WIND GUSTS  
ASSOCIATED WITH THESE STORMS, WHICH MAKES SENSE CONSIDERING THE  
THERMODYNAMIC ENVIRONMENT DESCRIBED ABOVE. AS SUCH, WHILE STORMS MAY  
STRUGGLE TO ORGANIZE BEYOND MUCH MORE THAN CLUSTERS OR POSSIBLY EVEN  
A FEW BROKEN LINE SEGMENTS, THE POTENTIAL FOR ISOLATED STRONG WIND  
GUSTS IN THAT 30 TO 60 MPH RANGE APPEARS TO BE REASONABLE.  
 
NOT ONLY THIS, BUT MOISTURE CONTENT IS ALSO RATHER HIGH ALONG AND  
SOUTH OF THE COLD FRONT, WITH PRECIPITABLE WATER VALUES RANGING  
FROM 1.8 TO 2.1 INCHES. WHILE SOUNDINGS DO SHOW PERHAPS SOME  
MODEST MID-LEVEL DRY AIR ENTRAINMENT IMPINGING ON UPDRAFTS, THIS  
HIGH MOISTURE CONTENT AND VERY DEEP WARM CLOUD DEPTHS SUPPORT AT  
LEAST BRIEFLY INTENSE RAIN RATES OF 1 TO 2 INCHES PER HOUR. STORMS  
WILL HAVE SOME FORWARD MOTION BUT WILL BE MOVING SLOWLY (10 TO 20  
MPH), AND THIS MAY LEAD TO A FEW POCKETS WHERE 1 TO 3 INCHES OF  
RAIN ACCUMULATES IN A VERY SHORT PERIOD OF TIME. THIS IS ALSO  
CORROBORATED BY HREF LPMM ANALYSIS AND INDIVIDUAL HIGH RESOLUTION  
MODEL MEMBERS. SOME LOCALIZED FLOODING WILL BE POSSIBLE AS A  
RESULT, ALTHOUGH WE DON'T EXPECT THIS TO BE COMMON OR WIDESPREAD,  
AND MAY REQUIRE SOME TRAINING OF STORMS IN ORDER TO OCCUR.  
 
THE MOST LIKELY WINDOW FOR THE MOST SIGNIFICANT HAZARDS APPEARS TO  
BE BETWEEN ROUGHLY 2 PM AND 8 PM, ALTHOUGH A FEW EARLIER STORMS ARE  
POSSIBLE, AS WELL AS A FEW STRAGGLERS THAT LINGER INTO THE EVENING  
AND OVERNIGHT BEFORE COMPLETELY DIMINISHING.  
 
19  
 

 
   
LONG TERM
 
(TUESDAY THROUGH NEXT SUNDAY)  
ISSUED AT 202 PM CDT SUN JUL 6 2025  
 
BY TOMORROW MORNING, THE COLD FRONT IS LIKELY TO SETTLE SOMEWHERE  
ACROSS SOUTHERN MISSOURI, AND MAY ALMOST COMPLETELY CLEAR OUR AREA.  
NORTH OF THE FRONT, DRIER AND AND MORE STABLE AIR IS LIKELY FILTER  
INTO MUCH OF OUR AREA, AND AS A RESULT OF THESE TRENDS, OUR  
PRECIPITATION CHANCES HAVE DROPPED CONSIDERABLY FROM PREVIOUS  
FORECASTS. IN FACT, MUCH OF OUR LOCAL AREA IS LIKELY TO REMAIN DRY  
TOMORROW, WITH THE EXCEPTION OF PARTS OF THE OZARKS AND SOUTHWEST  
ILLINOIS IN THE VICINITY OF THE STALLED FRONT. IN THIS LIMITED  
AREA, INSTABILITY IS LIKELY TO CLIMB ONCE AGAIN TO AROUND 1500 TO  
2000 J/KG OF SBCAPE, WITH ONLY AROUND 10-20KT OF 0-6KM SHEAR AND  
PRECIPITABLE WATER VALUES REACHING NEAR 1.8 INCHES. AS SUCH,  
SCATTERED THUNDERSTORMS WITH OCCASIONAL STRONG DOWNBURSTS AND  
HEAVY RAIN RATES REMAIN POSSIBLE TOMORROW AFTERNOON ALONG AND  
SOUTH OF WHEREVER THIS BOUNDARY SETTLES, ALTHOUGH THIS MAY NOT  
INCLUDE MUCH OF OUR FORECAST AREA AT ALL.  
 
ON TUESDAY, MODEST SOUTHERLY FLOW IS EXPECTED TO RETURN TO THE AREA,  
BRINGING MOISTURE-RICH AIR BACK TO THE NORTH. OVER THE COURSE OF THE  
DAY, A MID-LEVEL SHORTWAVE WILL MOVE ACROSS THE REGION, SENDING  
ANOTHER WEAK FRONT SOUTHWARD. AS THIS OCCURS IT WILL LIKELY TRIGGER  
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ACROSS THE REGION,  
ALTHOUGH CONFIDENCE REMAINS LOW REGARDING THE TIMING OF THE  
BOUNDARY. TRENDS OVER THE LAST 24 HOURS HAVE SHIFTED TOWARD AN  
EARLIER ARRIVAL OF THE FRONT AS OPPOSED TO OVERNIGHT, WHICH ALIGNS  
THE TIMING OF LOCAL STORMS WITH PEAK AFTERNOON HEATING AND AT LEAST  
INCREASES THE POTENTIAL FOR STRONGER ACTIVITY AS WELL. PROJECTED  
WIND SHEAR REMAINS WEAK THOUGH - ROUGHLY 15 TO 20KT OF 0-6KM BULK  
SHEAR - WHICH CONTINUES TO LIMIT THE UPPER POTENTIAL FOR STRONG OR  
SEVERE STORMS IN SPITE OF ROBUST INSTABILITY PROJECTIONS OF 2000-  
3000 J/KG OF SBCAPE. STILL, WE WILL NEED TO KEEP AN EYE ON THE  
POTENTIAL FOR DAMAGING DOWNBURSTS ONCE AGAIN, ALONG WITH HEAVY RAIN  
RATES AND LOCALIZED FLOODING.  
 
FOLLOWING TUESDAY'S WEAK FRONT AND SHOWERS/STORMS, SLIGHTLY DRIER  
AIR IS LIKELY TO MOVE INTO THE AREA, PERHAPS WITH INCREASING  
SUBSIDENCE ALOFT. AS SUCH, PRECIPITATION CHANCES WEDNESDAY AND  
THURSDAY HAVE DROPPED SLIGHTLY FROM PREVIOUS FORECASTS, ESPECIALLY  
IN AREAS NORTH OF THE I-44 CORRIDOR. WHILE SOME SHOWERS AND  
THUNDERSTORMS REMAIN POSSIBLE, LATEST TRENDS HAVE SHIFTED TOWARD  
THIS PERIOD BEING MORE DRY THAN WET. LATER IN THE WEEK THOUGH,  
ANOTHER, STRONGER SHORTWAVE REMAINS LIKELY TO MOVE ACROSS THE MIDDLE  
AND UPPER MISSISSIPPI VALLEY REGION, AND THIS MAY BRING YET ANOTHER  
ROUND OF SHOWERS AND THUNDERSTORMS TO THE REGION.  
 
AS FOR TEMPERATURES, LITTLE HAS CHANGED REGARDING THE FORECAST.  
AFTERNOON MAXIMUMS CONTINUE TO BE FORECAST NEAR SEASONAL AVERAGES  
FOR THE FORESEEABLE FUTURE, WITH PERHAPS A VERY SLIGHT INCREASING  
TREND LATE IN THE WEEK THANKS TO MODEST HEIGHT RISES AND LOWERING  
PRECIPITATION CHANCES.  
 
BRC  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)  
ISSUED AT 1039 PM CDT SUN JUL 6 2025  
 
COOL AND HUMID CONDITIONS OVERNIGHT MAY LEAD TO THE FORMATION OF  
FOG. HOWEVER, EXTENSIVE MID LEVEL CLOUD COVER IN THE WAKE OF  
SUNDAY AFTERNOON'S THUNDERSTORMS WILL LIKELY PREVENT THIS FROM  
OCCURRING IN MANY AREAS. SOME BREAKS IN THE CLOUDS ACROSS CENTRAL  
MISSOURI HAVE MADE IT A BIT MORE LIKELY THAT FOG FORMS AT COU AND  
JEF, WHILE THE ST LOUIS METRO HAS A SIGNIFICANTLY LOWER CHANCE DUE  
TO THAT CLOUD COVER. WINDS REMAIN LIGHT OVERNIGHT AND TOMORROW.  
ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED DURING THE AFTERNOON,  
BUT IT IS FORECAST TO REMAIN SOUTH OF ALL THE TAF SITES.  
 
KIMBLE  
 

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

 
 

 
 
WFO LSX  
 
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