667  
FXUS63 KIWX 180025  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
825 PM EDT FRI APR 17 2026  
   
KEY MESSAGES
 
 
- A LINE OF STRONG TO SEVERE STORMS IS EXPECTED TO MOVE IN  
LATER THIS EVENING AND SPREAD EAST OVERNIGHT. THE GREATEST  
SEVERE THREAT WILL EXIST WEST OF INTERSTATE 69 WITH DAMAGING  
WINDS AND POSSIBLY A TORNADO OR 2 THE MAIN CONCERN.  
 
- SOME HYDRO CONCERNS WILL EXIST TONIGHT AS LOCALLY HEAVY RAIN  
ACCOMPANIES THE LINE OF STORMS. OVERALL QPF AMOUNTS AND  
EXPECTED DURATION SHOULD LIMIT ADDITIONAL IMPACTS, BUT SOME  
AREAS COULD SEE LOCALIZED FLOODING ISSUES. THEREAFTER, NO  
ADDITIONAL SIGNIFICANT RAIN CHANCES ARE EXPECTED INTO NEXT  
WEEK.  
 
- MUCH COOLER TEMPERATURES ARRIVE AND PERSIST INTO EARLY NEXT  
WEEK WITH CHANCES FOR NEAR OR BELOW FREEZING TEMPS SUNDAY AND  
MONDAY MORNING.  
 
- RAIN CHANCES MAY RETURN TOWARDS THE END OF NEXT WEEK.  
 

 
   
DISCUSSION
 
 
ISSUED AT 226 PM EDT FRI APR 17 2026  
 
PRIMARY FORECAST FOCUS IS ON THE WELL ADVERTISED STRONG TO  
SEVERE STORM THREAT THIS EVENING INTO THE OVERNIGHT HOURS IN  
ASSOCIATION WITH A STRONG COLD FRONT AND PLENTIFUL UPPER LEVEL  
SUPPORT. DRY CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF  
THE AFTERNOON AND MOST LIKELY TO NEAR OR JUST AFTER 00Z. NUMEROUS  
THUNDERSTORMS ARE EXPECTED TO DEVELOP UPSTREAM (SOME ALREADY  
UNDERWAY FROM MINNESOTA TO NE MISSOURI) IN A STRONGLY FAVORABLE  
ENVIRONMENT FOR ALL MODES OF SEVERE. AS THESE STORMS RACES ENE,  
THEY SHOULD CONGEAL INTO 1 OR MORE LINES AND MOST LIKELY  
ESTABLISH STRONG COLD POOLS AS THEY MOVE ACROSS IL AND  
EVENTUALLY INTO PORTIONS OF INDIANA. IT REMAINS TO BE SEEN JUST  
HOW STRONG THEY ARE AS THEY ARRIVE LATER THIS EVENING, BUT  
CONCERNS HAVE INCREASED SOME THAT THEY MAKE IT ROUGHLY HALF WAY  
THROUGH THE AREA BEFORE WEAKENING SOMEWHAT. THIS IS DEPICTED BY  
SOME EXPANSION EAST OF THE SLIGHT AND MARGINAL RISK AREAS IN THE  
DY1 OUTLOOK. BY THIS POINT, HAIL SHOULD NOT BE A CONCERN, WITH  
AREAS OF WIND DAMAGE (60 TO 70 MPH) AS WELL AS SOME BRIEF  
TORNADOES WILL BE THE MAIN CONCERN. THE MAIN SEVERE THREAT  
SHOULD WRAP UP IN THE 6-8Z TIME FRAME WITH LINGERING STRATIFORM  
RAIN BEHIND THE MAIN LINE. POPS HAVE BEEN ADJUSTED FOR A  
SOMEWHAT FASTER TREND GIVEN THE IMPACTS OF THE COLD POOL PUSHING  
THE LINE ALONG SOONER THAN PREVIOUS INDICATIONS. WITH REGARDS  
TO HYDRO ISSUES, A FLOOD WATCH WAS CONTEMPLATED GIVEN THE  
POTENTIAL FOR 0.5" TO 1" OF RAIN (LOCALLY HIGHER POSSIBLE), BUT  
WITH THE LINE BEING SO PROGRESSIVE FEEL THE CONCERNS WILL BE  
RATHER LIMITED AND CAN JUST BE HANDLED BY FLOOD ADVISORIES OR  
WARNINGS AS NEEDED.  
 
THE FRONT WILL STALL OUT SOME SATURDAY AS ANOTHER WAVE MOVES  
ALONG IT. THE SEVERE THREAT SHOULD REMAIN TO OUR EAST BUT SOME  
SHOWERS AND MAYBE A STORM ARE STILL POSSIBLE IN SE AREAS,  
ESPECIALLY EARLY. AFTER THAT, WE ENTER A LESS ACTIVE PERIOD INTO  
AT LEAST THE MIDDLE OF NEXT WEEK WITH THE ONLY CONCERN BEING THE  
MONITORING OF COLDER TEMPERATURES AND FROST/FREEZE POTENTIAL  
SUNDAY AND MONDAY MORNING. WILL SORT THAT OUT AFTER WE GET THIS  
SYSTEM OUT OF HERE.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
 
 
ISSUED AT 804 PM EDT FRI APR 17 2026  
 
VFR CONDITIONS SHOULD PREVAIL THROUGH MID-TO-LATE EVENING WITH  
BKN TO OVC CEILINGS AROUND 10K FEET AGL AT BOTH KSBN AND KFWA. A  
LINE OF SHOWERS AND THUNDERSTORMS WILL TRACK EASTWARD ACROSS THE  
AREA OVERNIGHT, MAINLY BETWEEN 04Z AND 11Z SATURDAY. OCCASIONAL  
MVFR CONDITIONS WILL LIKELY ACCOMPANY THE HEAVIEST PRECIPITATION  
CORES, ALONG WITH GUSTY AND ERRATIC SURFACE WINDS. SHOWERS WILL  
LIKELY LINGER IN THE WAKE OF THIS CONVECTION W/ MVFR CEILINGS AT  
OR BELOW 2500 FEET AGL.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...NONE.  
OH...NONE.  
MI...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR LMZ043-046.  
 

 
 

 
 
DISCUSSION...FISHER  
AVIATION...HAMMER  
 
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