028  
FXUS63 KIWX 180734  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
334 AM EDT SAT APR 18 2026  
   
KEY MESSAGES  
 
- TONIGHT, THE RISK FOR SEVERE WEATHER HAS ENDED FOR TONIGHT.  
 
- PERIODS OF RAIN OVERNIGHT INTO SATURDAY MORNING, BUT THEN NO  
ADDITIONAL SIGNIFICANT RAIN CHANCES ARE EXPECTED UNTIL  
THURSDAY NIGHT INTO FRIDAY.  
 
- MUCH COOLER TEMPERATURES ARRIVE AND PERSIST INTO EARLY NEXT  
WEEK WITH CHANCES FOR NEAR OR BELOW FREEZING TEMPS SUNDAY AND  
MONDAY MORNING.  
 
 
   
DISCUSSION  
 
ISSUED AT 252 AM EDT SAT APR 18 2026  
 
TONIGHT AND SATURDAY:  
THE RISK FOR SEVERE WEATHER HAS ENDED FOR TONIGHT. STORMS HAVE  
LOST THE INSTABILITY AS EVIDENT BY THE LATEST LIGHTNING TRENDS,  
AND ARE NOW REDUCED TO MAINLY RAIN SHOWERS. THESE RAIN SHOWERS  
WILL PERSIST OVERNIGHT INTO SATURDAY MORNING AS AN UPPER LEVEL  
TROUGH TO THE WEST WILL STILL PROVIDE WIDESPREAD FORCING FOR  
ASCENT, BUT PRECIPITATION CHANCES END FROM WEST TO EAST ON  
SATURDAY AS COOLER AND DRIER AIR MOVE ACROSS THE REGION IN THE  
WAKE OF A COLD FRONT.  
 
ONE CHANGE TO THE FORECAST WAS TO ADD SOME SPRINKLES TO THE  
FORECAST FOR AREAS ALONG AND INLAND FROM THE LAKESHORE. FORECAST  
SOUDNINGS SHOW STRATUS WITH A NARROW AREA OF INSTABILITY, SO  
COULD HAVE SOME OF THE CLOUDS PRODUCE LIGHT PRECIPITATION.  
 
SUNDAY THROUGH FRIDAY:  
SEASONABLY COOL TEMPERATURES WILL LAST THROUGH THE WEEKEND, WITH  
HIGHS ON SUNDAY STRUGGLING TO REACH 50. A WEAK SHORTWAVE WILL  
MOVE ACROSS THE REGION, AND BRING SMALL CHANCES (20 PERCENT) FOR  
A FEW RAIN SHOWERS. ON SUNDAY NIGHT HIGH PRESSURE WILL BUILD IN,  
LEADING TO CLEAR SKIES AND LIGHT WINDS, WITH OVERNIGHT LOWS  
FALLING BELOW FREEZING BY MONDAY MORNING. MONDAYS HIGHS WILL  
REBOUND TO NEAR 50S.  
 
LOOKING AHEAD, HIGH PRESSURE WILL MOVE EASTWARD, AND RETURN FLOW  
WILL BRING SPRING-LIKE TEMPERATURES BACK ACROSS THE AREA. HIGHS  
ON TUESDAY WILL BE IN THE LOW 70S, MID 70S WEDNESDAY, AND NEAR  
80 BY THURSDAY.  
 
AS FOR PRECIPITATION CHANCES, THERE IS A SMALL CHANCE (15 TO 20  
PERCENT) A BOUNDARY COULD SPARK A FEW SHOWERS AND THUNDERSTORMS  
TUESDAY INTO WEDNESDAY. MORE WIDESPREAD RAIN CHANCES (50 TO 60  
PERCENT) RETURN LATE THURSDAY INTO FRIDAY AND A LARGER STORM  
SYSTEM APPROACHES FROM THE WEST. THE LONG RANGE MACHINE LEARNING  
GUIDANCE DOES INDICATE THIS SYSTEM COULD PRODUCE SEVERE WEATHER  
ACROSS THE CENTRAL CONUS, BUT THAT IS TOO FAR OUT IN THE FUTURE  
TO HAVE MUCH CONFIDENCE IN WHEN OR WHERE.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/  
 
ISSUED AT 149 AM EDT SAT APR 18 2026  
 
MAIN CHANGE TO THE TAFS WAS TO NARROW DOWN THE TIMING OF  
THUNDER BASED ON THE CURRENT TRENDS. ONCE THE LINE OF STORMS  
MOVES THROUGH, THE CHANCE FOR THUNDER DECREASES, SO TRIED TO  
TIME THIS LINE, AND THEN HAVE A PROLONGED PERIOD OF SHOWERS  
AFTER THAT. OTHERWISE EXPECT MVFR CEILINGS WITH WEST WINDS  
BECOMING NORTHWEST SATURDAY MORNING, WITH CEILINGS STARTING TO  
LIFT TO VFR LEVELS SATURDAY AFTERNOON. ONE OTHER CHANGE WAS TO  
ADD A PROB30 FOR SOME LIGHT RAIN SHOWERS SATURDAY EVENING.  
 
 
   
IWX WATCHES/WARNINGS/ADVISORIES  
 
IN...NONE.  
OH...NONE.  
MI...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR LMZ043-046.  
 
 
 
 
 
DISCUSSION...NWS  
AVIATION...NWS  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab IN Page
The Nexlab OH Page
The Nexlab MI Page
Main Text Page