839  
FXUS63 KLSX 031718  
AFDLSX  
 
AREA FORECAST DISCUSSION...UPDATED AVIATION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
1218 PM CDT FRI OCT 3 2025  
   
KEY MESSAGES  
 
- UNSEASONABLY WARM TEMPERATURES ARE EXPECTED TO CONTINUE THROUGH EARLY  
NEXT WEEK. TEMPERATURES WILL FALL BACK TO NEAR NORMAL BEHIND A  
COLD FRONT BY THE MIDDLE OF NEXT WEEK.  
 
- THE IS A SLIGHT CHANCE (20%) OF SHOWERS AND THUNDERSTORMS OVER  
PARTS OF THE AREA THIS AFTERNOON. THERE IS A BETTER CHANCE  
(30-40%) WITH THE COLD FRONT ON MONDAY NIGHT AND TUESDAY.  
 
 
   
SHORT TERM  
(THROUGH LATE SATURDAY AFTERNOON)  
ISSUED AT 321 AM CDT FRI OCT 3 2025  
 
THE LATEST WATER VAPOR IMAGERY WAS SHOWING AN UPPER TROUGH EXTENDING  
FROM THE GREAT LAKES THROUGH ILLINOIS INTO THE LOWER MISSISSIPPI  
VALLEY WITH A RIDGE JUST OFF TO THE WEST. CONDITIONS ARE DRY ACROSS  
THE AREA EARLY THIS MORNING DESPITE THE TROUGH AS THERE IS LITTLE  
INSTABILITY OR LOW LEVEL FORCING FOR IT TO ACT ON. THE RAP AND  
NAM IS SHOWING THAT THE TROUGH WILL SUPPLY SOME WEAK LIFT IN THE  
INTO THIS AFTERNOON ACROSS FAR EASTERN MO INTO SOUTH CENTRAL  
ILLINOIS AS IT SLOWLY WEAKENS WITH TIME. THIS IS THE SAME AREA  
THAT WILL BECOME WEAKLY CAPPED BY THIS AFTERNOON WITH MUCAPES OF  
500-1000 J/KG, SO HAVE INCLUDED SLIGHT CHANCES (10-20%) FOR  
SHOWERS AND THUNDERSTORMS. ANY CONVECTION WILL RAPIDLY DISSIPATE  
EARLY THIS EVENING WITH THE LOSS OF DAYTIME HEATING.  
 
TEMPERATURES EARLY THIS MORNING ARE ALL IN THE 60S ACROSS THE AREA,  
SO WITH WARM START AND SIMILAR CONDITIONS TO YESTERDAY, WENT WITH  
HIGHS IN THE UPPER 80S TO NEAR 90 TODAY. LOWS TONIGHT WILL BE IN  
THE LOWER 60S, WITH A FEW UPPER 50S IN RIVER VALLEYS AND OVER  
SOUTHEAST MISSOURI.  
 
BRITT  
 
 
   
LONG TERM  
(SATURDAY NIGHT THROUGH THURSDAY)  
ISSUED AT 321 AM CDT FRI OCT 3 2025  
 
IT STILL LOOKS THE WEEKEND WILL BE MAINLY DRY AS THE UPPER RIDGE  
MOVES BACK OVER MISSOURI AND ILLINOIS. RAIN CHANCES SHOW UP AS  
EARLY AS MONDAY AS BOTH THE GLOBAL MODELS AND THEIR ENSEMBLES ARE  
BEGIN TO INCREASE (20%) OVER THE NORTHERN CWA ASSOCIATED WITH A  
TROUGH/FRONT AND IN THE SOUTH WITH INCREASED MOISTURE TRANSPORT FROM  
THE GULF. THE CHANCES WILL INCREASE (MONDAY NIGHT THROUGH TUESDAY)  
WHEN THE AFOREMENTIONED TROUGH WILL PASS THROUGH THE GREAT LAKES AND  
BRING A COLD FRONT ACROSS MISSOURI AND ILLINOIS. THE LREF IS  
SHOWING 30-40% OF ITS MEMBERS PRODUCING PRECIPITATION DURING THIS  
TIMEFRAME BEFORE DRY WEATHER RETURNS WEDNESDAY INTO THURSDAY AS  
ANOTHER RIDGE WILL MOVE INTO THE MIDWEST. AS MENTIONED IN PREVIOUS  
DISCUSSIONS, SIGNIFICANT RAINFALL DOES NOT SEEM LIKELY AS THE  
LREF CHANCES FOR SEEING >0.5" OVER THE CWA BY NEXT THURSDAY IS  
<25%. LIKEWISE, SEVERE WEATHER CHANCES LOOK LOW THROUGH THE END OF  
NEXT WEEK.  
 
HIGHS ARE EXPECTED TO STAY WELL INTO THE 80S THROUGH MONDAY AHEAD OF  
THE FRONT BEFORE DROPPING BACK INTO THE 70S ON WEDNESDAY AND  
THURSDAY WHICH IS NEAR NORMAL FOR EARLY-MID OCTOBER. THE NBM IQR  
AT STL IS ONLY 1-3 DEGREES THROUGH MONDAY, BUT THEN INCREASES TO 6-  
10 DEGREES BY MID-LATE NEXT WEEK SHOWING THAT THERE IS A SPREAD IN  
THE MODELS AND INCREASING UNCERTAINTY IN THE FORECAST.  
 
BRITT  
 
 
   
AVIATION  
(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)  
ISSUED AT 1215 PM CDT FRI OCT 3 2025  
 
ISOLATED POP-UP SHOWERS AND THUNDERSTORMS ARE FORECAST MOSTLY  
NORTH OF I-70 THIS AFTERNOON. THE CHANCES OF THESE IMPACTING ANY  
GIVEN TERMINAL ARE LOW, SO LEFT MENTION FROM THE TAFS. IF A SHOWER  
OR STORM DOES IMPACT A TERMINAL, EXPECT BRIEF MODERATE TO HEAVY  
RAIN AND REDUCED VISIBILITIES. FOR ALL NOT IMPACTED, DRY AND VFR  
CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD.  
 
JAJA  
 
 
   
LSX WATCHES/WARNINGS/ADVISORIES  
 
MO...NONE.  
IL...NONE.  
 
 
 
 
WFO LSX  
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