976  
FXUS63 KIWX 170943  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
543 AM EDT THU SEP 17 2026  
   
KEY MESSAGES  
 
- NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED THIS MORNING.  
HEAVY RAIN AND ASSOCIATED FLOODING POTENTIAL ARE THE GREATEST  
CONCERN, ESPECIALLY IN AREAS THAT EXPERIENCED HEAVY RAIN OVER  
THE PAST 24 TO 36 HOURS. A FLOOD WATCH IS IN EFFECT FOR PARTS  
OF NORTHERN INDIANA AND NORTHWEST OHIO.  
 
- DRY AND LESS HUMID CONDITIONS ON FRIDAY FOLLOWED BY RENEWED  
OPPORTUNTIES FOR RAIN AND STORMS THIS WEEKEND.  
 
 
   
DISCUSSION  
 
ISSUED AT 241 AM EDT THU SEP 17 2026  
 
MOISTURE ADVECTION WITHIN A BROAD ~25 KNOT LOW LEVEL JET SUPPORTING  
ADDITIONAL ROUNDS OF SHOWERS AND EMBEDDED STORMS IN THE VICINITY OF  
A STALLED BAROCLINIC ZONE THIS MORNING. SOME UPPER JET SUPPORT ALSO  
NOTED FROM A SHORTWAVE AND MID-UPPER LEVEL JET TRACKING EAST THROUGH  
THE NORTHERN GREAT LAKES AIDING IN SOME WEAK FRONTOGENESIS. HEAVY  
RAINFALL RATES AND THE RESULTING POTENTIAL FOR MORE LOCALIZED  
FLOODING THE MAIN THREAT WITH THIS ROUND GIVEN THE ANOMALOUSLY MOIST  
COLUMN AND POTENTIAL FOR TRAINING. ANTECEDENT CONDITIONS FAVOR AREAS  
NEAR AND SOUTH OF FORT WAYNE AREA FOR GREATEST FLOOD THREAT. DID OPT  
TO ADD A ROW OF COUNTIES ON THE NORTHERN FRINGE OF THE FLOOD WATCH  
GIVEN RADAR/MODEL TRENDS. LOW CLOUDS AND SOME PATCHY FOG EXPECTED  
OTHERWISE THIS MORNING.  
 
CHANCES FOR RAIN DIMINISH THIS AFTERNOON INTO THIS EVENING AS THE  
LOW LEVEL JET WEAKENS AND THE PRIMARY MUCAPE AXIS SHIFTS OFF THE  
SOUTHWEST. WITH THAT SAID CANNOT RULE THE LOW CHANCE FOR A FEW  
WIDELY SCATTERED SHOWERS WITHIN THE ELEVATED PORTION OF THE  
SOUTHWARD SINKING FRONTAL SLOPE, MAINLY SOUTH OF US 30 CORRIDOR IN  
IN. A LOW LEVEL ANTICYCLONE DROPPING SOUTHEAST THROUGH THE  
NORTHERN/EASTERN GREAT LAKES SHUNTS THE BOUNDARY WELL SOUTH  
LATER TONIGHT INTO FRIDAY WITH A BRIEF SHOT OF LOWER HUMIDITY  
AND DRY CONDITIONS FOR THE ENTIRE FORECAST AREA.  
 
ANOTHER WET PATTERN EMERGES THIS WEEKEND AS SEVERAL UPPER LEVEL  
WAVES EJECT EAST OVER A PERSISTENT UPPER RIDGE. THE ASSOCIATED LIFT  
AND SURGES OF THETA-E SHOULD FOCUS SEVERAL ROUNDS OF SHOWERS AND  
STORMS IN THE VICINITY OF A BAROCLINIC ZONE THAT LOOKS TO SINK SOUTH  
INTO THE AREA ON SATURDAY, POTENTIALLY LINGERING OVER THE AREA INTO  
SUNDAY AND MONDAY. RIVER AND LOWLAND FLOODING MAY ONCE AGAIN BECOME  
AN ISSUE FOR PORTIONS OF THE AREA.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/  
 
ISSUED AT 542 AM EDT THU SEP 17 2026  
 
MOISTURE TRANSPORT INTO A STALLED FRONTAL ZONE WILL ALLOW  
SHOWERS AND FEW EMBEDDED STORMS TO IMPACT THE TERMINALS THIS  
MORNING. THE BULK OF THE MORNING WILL GENERALLY FEATURE LIFR TO  
IFR CONDITIONS GIVEN MOIST CONDITIONS WITHIN THE LINGERING  
BAROCLINIC ZONE. SOME DRYING AND DIURNAL MIXING SHOULD SUPPORT  
IMPROVEMENT BACK INTO MAINLY MVFR WITH TIME THIS AFTERNOON. A  
FEW SHOWERS MAY DEVELOP THIS AFTERNOON INTO THIS EVENING, THOUGH  
CHANCES (10-20%) ARE TOO LOW FOR A MENTION AT THIS TIME. LIGHT  
WINDS EXPECTED OTHERWISE THROUGH THE TAF CYCLE.  
 
 
   
IWX WATCHES/WARNINGS/ADVISORIES  
 
IN...FLOOD WATCH UNTIL 2 PM EDT THIS AFTERNOON FOR INZ017-018-  
023>027-032>034.  
OH...FLOOD WATCH UNTIL 2 PM EDT THIS AFTERNOON FOR OHZ024-025.  
MI...NONE.  
MARINE...NONE.  
 
 
 
 
 
DISCUSSION...STEINWEDEL  
AVIATION...STEINWEDEL  
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