512  
FXUS63 KIND 081014  
AFDIND  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE INDIANAPOLIS IN  
614 AM EDT TUE SEP 8 2026  
   
KEY MESSAGES  
 
- HEAT RETURNS TODAY AND WEDNESDAY WITH PEAK HEAT INDICES IN THE  
UPPER 90S AND LOW 100S WEDNESDAY AFTERNOON  
 
- STRONG THUNDERSTORMS POSSIBLE LATE WEDNESDAY; RAIN AND STORMS  
CONTINUE WEDNESDAY NIGHT INTO THURSDAY WITH HEAVY RAIN AND LOCALIZED  
FLOODING AS THE PRIMARY CONCERN  
 
- COOLER WEATHER RETURNS LATE WEEK  
 
 
   
DISCUSSION (TODAY THROUGH MONDAY)  
 
ISSUED AT 252 AM EDT TUE SEP 8 2026  
 
AFTER A COUPLE DAYS WITH MORE SEASONABLE TEMPERATURES...WARMER AIR  
WILL RETURN TO THE OHIO VALLEY AS RIDGING ALOFT ONCE AGAIN EXPANDS  
BACK INTO THE REGION THROUGH MIDWEEK. THE RIDGE WILL FLATTEN ON  
WEDNESDAY IN RESPONSE TO A SHARP UPPER TROUGH TRAVERSING THROUGH  
SOUTHERN CANADA. THIS WILL ENABLE A FRONTAL BOUNDARY TO DRIFT INTO  
THE AREA LATE WEDNESDAY WITH CHANCES FOR RAIN AND THUNDERSTORMS INTO  
THURSDAY AS IT SHIFTS SLOWLY SOUTH. DRY AND SEASONABLE CONDITIONS  
RETURN FOR LATE WEEK BUT WAVES ALOFT RIDING WITHIN A LARGELY ZONAL  
FLOW WILL CONTRIBUTE TO ISOLATED TO SCATTERED CONVECTION THIS  
WEEKEND INTO NEXT WEEK.  
 
TODAY THROUGH THURSDAY  
 
QUIET EARLY MORNING AS THE REGION REMAINS UNDER THE INFLUENCE OF  
HIGH PRESSURE. CIRRUS WAS SPILLING OVERTOP OF THE UPPER LEVEL RIDGE  
CENTERED TO OUR WEST. 06Z TEMPERATURES WERE GENERALLY IN THE 60S.  
 
THE CENTER OF THE AFOREMENTIONED HIGH WILL SHIFT SOUTH THROUGH THE  
MID ATLANTIC REGION RESULTING IN RETURN FLOW ADVECTING WARMER AND  
PROGRESSIVELY MORE HUMID AIR INTO THE OHIO VALLEY BY WEDNESDAY. THE  
EXPANSION OF THE RIDGE CURRENTLY CENTERED OVER THE SOUTHERN PLAINS  
WILL COMMENCE TODAY WITH LOW LEVEL THERMALS SUPPORTIVE OF HIGHS  
RETURNING TO A RANGE FROM THE UPPER 80S IN THE NORTHEAST TO THE MID  
90S IN THE LOWER WABASH VALLEY. HIGHER DEWPOINT AIR WILL LAG THE  
TEMP RISES AND OVERALL HUMIDITY LEVELS THIS AFTERNOON DURING PEAK  
HEATING WILL BE MANAGEABLE KEEPING PEAK HEAT INDICES IN THE LOWER  
AND MID 90S. THE ONSET OF S/SW WINDS WILL AID IN DIURNAL CU  
FORMATION BY MIDDAY PARTICULARLY IN THE VICINITY OF A SUBTLE  
INVERTED TROUGH THAT WILL WASH OUT THIS MORNING ACROSS THE SOUTHEAST  
HALF OF THE FORECAST AREA.  
 
MORE HUMID AIR WILL ADVECT INTO THE REGION TONIGHT AND ESPECIALLY  
WEDNESDAY SETTING THE STAGE FOR THE HOTTEST DAY OF THE WEEK. THE  
APPROACH OF A COLD FRONT FROM THE NORTH MAY PRODUCE A COMPRESSIONAL  
HEATING COMPONENT THAT COULD ENABLE TEMPERATURES TO OVERPRODUCE ON  
WEDNESDAY. THE WILD CARD WILL BE WHETHER ANY REMNANTS OF CONVECTION  
OR ASSOCIATED CLOUDS OVER THE UPPER MISSISSIPPI VALLEY LATE TONIGHT  
AND EARLY WEDNESDAY CAN MAKE IT INTO THE FORECAST AREA BY MIDDAY  
WEDNESDAY AND DISRUPT EXPECTED HEATING. THERMAL PROFILES DO SUPPORT  
LOW TO MID 90S FOR HIGHS AND THE INCREASE IN HUMIDITY SUGGEST HEAT  
INDICES WILL RISE INTO THE UPPER 90S AND LOWER 100S DURING THE  
AFTERNOON.  
 
SCATTERED CONVECTION WILL BE POSSIBLE AS THE AFTERNOON PROGRESSES  
WEDNESDAY BUT EXPECT MORE COVERAGE BY THE EVENING AS THE BOUNDARY  
SLIDES INTO THE AREA AND INTERACTS WITH AN AXIS OF GREATER  
INSTABILITY BISECTING THE FORECAST AREA FROM SOUTHWEST TO NORTHEAST.  
INITIAL CONVECTION WEDNESDAY EVENING WILL CARRY A RISK FOR DAMAGING  
WINDS IN THE STRONGEST CELLS WITH MODEST DCAPE VALUES AT 800-1000  
J/KG. A LACK OF BL SHEAR ALONG THE BOUNDARY HOWEVER WILL LIKELY  
FORCE A MORE PULSE INTENSITY CONVECTIVE PROFILE BEFORE STORMS SETTLE  
INTO A SUBSEVERE STATE WEDNESDAY NIGHT WITH THE FOCUS SHIFTING MORE  
TO HEAVY RAIN AND LOCALIZED FLOODING. THE FRONTAL BOUNDARY WILL SLOW  
AS IT BECOMES NEAR PARALLEL TO THE UPPER FLOW THROUGH THE NIGHT AND  
INTO THURSDAY WITH THE POTENTIAL FOR STORMS TO TRAVERSE ACROSS THE  
SAME AREAS ALONG AND SOUTH OF THE I-70 CORRIDOR. WITH PWATS PEAKING  
NEAR 2 INCHES...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE UNTIL THE  
FRONT CAN SHIFT SOUTH OF THE AREA THURSDAY NIGHT. 1 TO 2 INCHES IS  
POSSIBLE WITH LOCALLY HIGHER AMOUNTS BETWEEN WEDNESDAY AFTERNOON AND  
LATE THURSDAY.  
 
THURSDAY NIGHT THROUGH MONDAY  
 
THE COLD FRONT WILL SHIFT SOUTH OF THE AREA THURSDAY NIGHT BEFORE  
GRADUALLY WASHING OUT ACROSS THE TENNESSEE VALLEY ON FRIDAY AS THE  
BOUNDARY RUNS INTO THE RIDGE OVER THE SOUTHEAST STATES. WEAK HIGH  
PRESSURE WILL TRACK THROUGH THE GREAT LAKES FOR LATE WEEK WITH DRY  
AND COOLER CONDITIONS ACROSS CENTRAL INDIANA. HIGHS ON FRIDAY WILL  
BE IN THE UPPER 70S AND LOWER 80S.  
 
AS THE HIGH SHIFTS INTO NEW ENGLAND BY EARLY SATURDAY...RETURN FLOW  
WILL DRAW THE REMNANT MOISTURE FROM THE AFOREMENTIONED FRONT BACK  
NORTH INTO THE REGION IN ADVANCE OF A SECONDARY BOUNDARY OVER THE  
UPPER MIDWEST. FORCING ALOFT IS NOT OVERLY IMPRESSIVE BUT THE INFLUX  
OF MOISTURE AND INSTABILITY INTO THE REGION WILL LIKELY BE ENOUGH TO  
GENERATE ISOLATED TO SCATTERED CONVECTION ON BOTH SATURDAY AND  
SUNDAY. DEVELOPING LOW PRESSURE OVER THE HIGH PLAINS EARLY NEXT WEEK  
WILL SHIFT A WARM FRONT INTO THE LOWER GREAT LAKES AND ENABLE HIGHS  
TO AGAIN RISE INTO THE MID AND UPPER 80S. SCATTERED CONVECTION IS  
POSSIBLE ON MONDAY AS WELL WITH MORE WIDESPREAD RAIN AND STORMS  
EXPECTED BY TUESDAY AS THE LOW TRACKS INTO THE REGION.  
 
 
   
AVIATION (12Z TAF ISSUANCE)  
 
ISSUED AT 614 AM EDT TUE SEP 8 2026  
 
IMPACTS:  
 
- NONE  
 
DISCUSSION:  
 
HIGH PRESSURE WILL MOVE SOUTH THROUGH THE MID ATLANTIC REGION TODAY  
MAINTAINING DRY WEATHER ACROSS CENTRAL INDIANA. CIRRUS WILL DRIFT  
ACROSS THE REGION AT TIMES TODAY WITH DIURNAL CU DEVELOPING BY  
MIDDAY AS WINDS VEER TO S/SW. CU WILL DIMINISH NEAR OR JUST AFTER  
SUNSET WITH LIGHT S/SE WINDS TONIGHT. MID AND HIGH LEVEL CLOUDS WILL  
INCREASE LATE TONIGHT FROM CONVECTION UPSTREAM ACROSS THE UPPER  
MISSISSIPPI VALLEY.  
 
 
   
IND WATCHES/WARNINGS/ADVISORIES  
NONE.  
 
 
 
 
 
AVIATION...RYAN  
DISCUSSION...RYAN  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab IN Page
Main Text Page