285  
FXUS63 KLSX 060900  
AFDLSX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAINT LOUIS MO  
400 AM CDT SUN JUL 6 2025  
   
KEY MESSAGES  
 
- SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED  
THIS AFTERNOON INTO EARLY EVENING ACROSS CENTRAL AND EASTERN  
MISSOURI INTO SOUTHWEST AND WEST CENTRAL ILLINOIS. SOME STORMS  
COULD PRODUCE LOCALLY HEAVY DOWNPOURS AND GUSTY WINDS.  
 
- SEASONABLY WARM AND HUMID WEATHER WILL CONTINUE INTO THE WORK-  
WEEK WITH A CHANCE FOR MAINLY AFTERNOON AND EVENING SHOWERS AND  
THUNDERSTORMS.  
 
 
   
SHORT TERM  
(THROUGH LATE TONIGHT)  
ISSUED AT 357 AM CDT SUN JUL 6 2025  
 
ONGOING CONVECTION IS BEING FUELED BY MOISTURE CONVERGENCE DRIVEN BY  
A WEAK LOW LEVEL JET AHEAD OF A COLD FRONT WHICH IS MOVING INTO  
MISSOURI THIS MORNING. THE FRONT WILL CONTINUE TO SAG SOUTHEAST  
TODAY, DRIVEN BY A SHORT WAVE TROUGH MOVING MOVING THROUGH THE  
MIDWEST. THIS FRONT WILL CONTINUE TO BE A FOCUS FOR CONVECTION TODAY  
AND TONIGHT AS IT DRIFTS SOUTHEAST INTO THE FORECAST AREA. GUIDANCE  
IS SOMEWHAT DIVIDED ON CONVECTIVE TRENDS THIS MORNING, WITH SOME  
MODELS SHOWING STORMS DISSIPATING BY 12-14Z, AND OTHERS SHOWING  
ISOLATED TO WIDELY SCATTERED SHOWERS AND STORMS CONTINUING THROUGH  
THE MORNING HOURS. HOWEVER, THERE IS CONSENSUS IN INCREASING  
COVERAGE THIS AFTERNOON ALONG AND AHEAD OF THE COLD FRONT ACROSS  
CENTRAL AND SOUTHEAST MISSOURI INTO SOUTHWEST AND SOUTH CENTRAL  
ILLINOIS. THE 60-70 POPS IN THE GOING FORECAST CONTINUE TO LOOK GOOD  
FOR THIS AFTERNOON, WITH DECREASING POPS IN THE EVENING AS DIURNAL  
HEATING WANES. SHORT RANGE GUIDANCE SHOWS THE FRONT STALLING  
TONIGHT SOMEWHERE BETWEEN I-70 AND I-44 IN MISSOURI, AND JUST SOUTH  
OF I-70 IN ILLINOIS. ISOLATED TO WIDELY SCATTERED SHOWERS AND  
STORMS WILL LIKELY CONTINUE OVERNIGHT DUE TO LOW LEVEL MOISTURE  
CONVERGENCE IN THE VICINITY OF THE FRONT. LOCALIZED HEAVY DOWNPOURS  
AND POSSIBLE WET MICROBURSTS CONTINUE TO BE POSSIBLE WITH THESE  
STORMS. TEMPERATURES THIS AFTERNOON SHOULD BE A FEW DEGREES COOLER  
THAN SATURDAY DUE TO MORE CLOUD COVER AND AFTERNOON STORMS.  
 
CARNEY  
 
 
   
LONG TERM  
(MONDAY THROUGH SATURDAY)  
ISSUED AT 357 AM CDT SUN JUL 6 2025  
 
THERE'S BEEN LITTLE CHANGE TO THE FORECAST FOR MONDAY THROUGH NEXT  
SATURDAY. THE FRONT REMAINS NEARLY STATIONARY NEAR OR JUST SOUTH OF  
I-70 FOR MUCH OF THE DAY. HOWEVER THE POSITION OF THE EFFECTIVE  
BOUNDARY WILL MOST LIKELY BE CONTROLLED BY CONVECTION/OUTFLOWS  
THROUGH THE DAY. WHILE CONVECTION IN THE VICINITY OF THE FRONT ON  
MONDAY, THE COVERAGE IS QUESTIONABLE WITH SOME MODELS SHOWING  
WIDESPREAD QPF ALONG AND SOUTH OF THE FRONT, AND OTHERS (INCLUDING  
MOST CAMS) KEEPING COVERAGE MORE IN THE 20-50% RANGE. CURRENTLY  
LEANING TOWARD THE 20-50% RANGE GIVEN THE UNCERTAINTY IN FRONTAL  
POSITION, BUT THIS MAY NEED TO BE INCREASED IN SUBSEQUENT FORECASTS.  
 
THE NEXT UPSTREAM SHORT WAVE MOVE FROM THE PLAINS INTO THE MIDWEST  
TUESDAY, WHICH ALONG WITH THE LINGERING FRONT, WILL PRODUCE MORE  
THUNDERSTORMS. THE DETERMINISTIC GFS CONTINUES TO LOOK LIKE IT'S  
CONTAMINATED WITH CONVECTIVE FEEDBACK, HOWEVER IT'S SHOWING 2300+  
J/KG MLCAPE AT 18Z TUESDAY ACROSS PARTS OF WESTERN AND CENTRAL  
MISSOURI, AND THIS AGREES WELL WITH LREF MEAN SBCAPE. INVERTED V  
FORECAST SOUNDINGS INDICATE THE POSSIBILITY OF WET MICROBURSTS, BUT  
THE 0-6KM SHEAR IS ONLY 15-20KTS. WHILE THERE COULD BE A FEW  
STRONG/SEVERE STORMS, ORGANIZED SEVERE STORMS ARE UNLIKELY DUE TO  
THE LACK OF STRONG DEEP-LAYER SHEAR.  
 
WEAK NORTHWEST TO OCCASIONAL ZONAL FLOW CONTINUES FOR THE REST OF  
THE WORK-WEEK AS THE UPPER PATTERN IS FIRST AMPLIFIED BY TUESDAY'S  
SHORT WAVE, AND THEN THE SOUTHWEST UPPER RIDGE IS ATTENUATED BY  
ANOTHER WAVE WHICH MOVES ACROSS THE NORTHERN 1/2 OF THE CONUS AND  
SOUTHERN CANADA FRIDAY AND SATURDAY. SENSIBLE WEATHER AT THE  
SURFACE WILL CHANGE LITTLE DURING THIS PERIOD, WITH MOSTLY AFTERNOON  
AND EVENING CONVECTION DRIVEN BY DIURNAL HEATING. TEMPERATURES LOOK  
SEASONABLY WARM AND HUMID WITH HIGHS MAINLY IN THE UPPER 80S TO LOW  
90S. THERE MAY BE SOME RELIEF FROM THE HEAT SATURDAY IF THE  
AFOREMENTIONED SHORTWAVE DIGS FARTHER SOUTH INTO THE MIDWEST OR  
GREAT LAKES WHICH WOULD PUSH THE ASSOCIATED COLD FRONT FARTHER INTO  
THE MISSISSIPPI VALLEY.  
 
CARNEY  
 
 
   
AVIATION  
(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)  
ISSUED AT 1035 PM CDT SAT JUL 5 2025  
 
SCATTERED THUNDERSTORMS ARE EXPECTED TO ENTER NORTHEAST MISSOURI  
SHORTLY, BUT ARE FORECAST TO GRADUALLY WEAKEN AND DISSIPATE  
OVERNIGHT. WHILE THE THREAT FOR THUNDERSTORMS IS NOT ZERO VERY LATE  
TONIGHT INTO EARLY SUNDAY MORNING, IT IS VERY LOW. COVERAGE OF  
STORMS SHOULD INCREASE JUST AFTER MIDDAY ON SUNDAY, WITH THE BEST  
CHANCES FROM THE ST. LOUIS METRO AND POINTS SOUTH. ADDED A TEMPO  
AT THE METRO TERMINALS FOR THUNDERSTORMS, ROUGHLY BETWEEN 19 AND  
23 UTC. ANY STORM THAT DOES DIRECTLY IMPACT A SITE WILL BE CAPABLE  
OF HEAVY DOWNPOURS/REDUCED VISIBILITIES AND POTENTIALLY GUSTY  
WINDS.  
 
GOSSELIN  
 
 
   
LSX WATCHES/WARNINGS/ADVISORIES  
 
MO...NONE.  
IL...NONE.  
 
 
 
 
WFO LSX  
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