607  
FXUS63 KLSX 011100  
AFDLSX  
 
AREA FORECAST DISCUSSION...UPDATED AVIATION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
600 AM CDT MON SEP 1 2025  
   
KEY MESSAGES  
 
- LARGELY DRY AND COMFORTABLE CONDITIONS CONTINUE THROUGH  
WEDNESDAY MORNING BEFORE A STRONG COLD FRONT MID-WEEK. ALONG  
WITH SHOWERS AND A RUMBLE OF THUNDER, THE FRONT WILL USHER IN A  
NOTABLE COOLDOWN THROUGH EARLY NEXT WEEK.  
 
 
   
SHORT TERM  
(THROUGH LATE TUESDAY AFTERNOON)  
ISSUED AT 245 AM CDT MON SEP 1 2025  
 
DRY AIR IS ADVECTING WEST AMIDST WEAK BUT PERSISTENT EASTERLY  
NEAR- SURFACE FLOW AS WE ENTER CLIMATOLOGICAL FALL. WHILE MID-  
LEVEL FORCING CONTINUES TO STIMULATE WEAK SHOWERS ACROSS WESTERN  
MISSOURI, THE DRY AIR IS INHIBITING ALL BUT A FEW CELLS FROM  
PRECIPITATING FURTHER EAST. WHILE LOW (15-25%) RAIN CHANCES  
CONTINUE TODAY IN CENTRAL MISSOURI, MOST OF THE REGION WILL ENJOY  
A DRY LABOR DAY WITH VERY SIMILAR CONDITIONS TO YESTERDAY.  
TEMPERATURES WILL BE FURTHER STUNTED IN CENTRAL MISSOURI WHERE  
CLOUD COVER REMAINS MORE ABUNDANT, BUT WILL BE GENERALLY BELOW-  
NORMAL AREAWIDE. THE MID-LEVEL WAVE CAUSING THE SHOWERS IS STILL  
EXPECTED TO SLIDE SOUTH AND EAST THROUGH THE EVENING AND SETTLE  
OVER THE OZARKS ON TUESDAY. WHILE TEMPERATURES WILL STAY SOMEWHAT  
SUPPRESSED (UPPER 70S TO LOW 80S) DURING THE DAY, RAIN CHANCES  
WILL BE FAIRLY LOW (20%) AND CONFINED TO THE OZARKS THEMSELVES.  
 
MRB  
 
 
   
LONG TERM  
(TUESDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 245 AM CDT MON SEP 1 2025  
 
MOST GUIDANCE IS NOW SUGGESTING A BRIEF WARMUP ON WEDNESDAY AHEAD OF  
A STRONG COLD FRONT AND IMPRESSIVE CLOSED UPPER LEVEL LOW DIVING  
SOUTH FROM CENTRAL CANADA. WARMER WESTERLY WINDS AND DECREASED CLOUD  
COVER WILL SEND TEMPERATURES BACK TO NEAR-NORMAL AHEAD OF THE FRONT,  
ROUGHLY IN THE MID-80S FOR MOST OF THE AREA. MOST SOLUTIONS DON'T  
BRING THE FRONT INTO THE NORTHERN FORECAST AREA UNTIL AROUND SUNSET.  
ONCE HERE, CONFIDENCE IS INCREASING THAT SHOWERS WILL FILL IN ALONG  
THE FRONT AND BRING OUR BEST CHANCE FOR MORE THAN A FEW HUNDREDTHS  
OF AN INCH OF RAIN IN THE NEXT WEEK. THAT SAID, CONVECTION WILL BE  
FAIRLY WEAK, IF IT CAN OCCUR AT ALL WITH WAINING MUCAPE VALUES IN  
MOST AVAILABLE GUIDANCE BY THE TIME THE FRONT ARRIVES. NBM  
PROBABILITIES OF 0.50 INCHES OF RAIN WEDNESDAY NIGHT NEVER TOPS MORE  
THAN 15%, WHICH DOESN'T BODE WELL FOR THE GRADUALLY-WORSENING  
DROUGHT.  
 
WHILE IT'S NOT UNCOMMON TO SEE COLD AIR LAG BEHIND THE EFFECTIVE  
COLD FRONT THIS TIME OF YEAR, THAT WILL CERTAINLY NOT BE THE CASE  
THURSDAY MORNING. MUCH COOLER AND DRIER AIR WILL RUSH INTO THE  
REGION BY THURSDAY, SENDING TEMPERATURES ANYWHERE FROM 10-15 DEGREES  
BELOW WEDNESDAY'S HIGHS. THE COOLEST CONDITIONS WILL BE ACROSS  
NORTHERN MISSOURI, WHERE HIGHS WILL STRUGGLE TO WARM TO 70 DEGREES.  
ELSEWHERE, UPPER 60S TO LOW 70 ARE FORECAST AND A STELLAR WEEKEND IS  
ON TAP. THE TREND FOR A MORE PERSISTENT COOLDOWN, AT LEAST THROUGH  
THE WEEKEND, ALSO CONTINUES WITH A REINFORCING COLD FRONT DIVING  
SOUTH FRIDAY EVENING. THIS COOLDOWN LOOKS MORE LIKELY TO LAST  
THROUGH THE WEEKEND, BUT THOSE WHO ARE HERALDING THIS COOLDOWN AS  
THE "END OF SUMMER" MAY WANT TO HOLD OFF ON THAT RHETORIC. THE NBM  
TEMPERATURE ENVELOPE SHOWS A PERSISTENT WARMING TREND GOING INTO THE  
MIDDLE OF NEXT WEEK, WHICH MATCHES THE CPC TEMPERATURE OUTLOOKS AND  
CIPS EXTENDED ANALOG GUIDANCE FROM SAINT LOUIS UNIVERSITY.  
 
MRB  
 
 
   
AVIATION  
(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)  
ISSUED AT 600 AM CDT MON SEP 1 2025  
 
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. A LOW RAIN  
THREAT PERSISTS AT THE CENTRAL MISSOURI TAFS, HENCE THE PROB30S FOR  
SHRA THIS AFTERNOON. NO IMPACTS ARE EXPECTED FROM THESE SHOWERS,  
WITH THE MAIN THRUST OF FORCING DISPLACED FAR ENOUGH TO THE WEST OF  
THE REGIONAL TERMINALS.  
 
MRB  
 
 
   
LSX WATCHES/WARNINGS/ADVISORIES  
 
MO...NONE.  
IL...NONE.  
 
 
 
 
WFO LSX  
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