798
FXUS63 KIWX 180556
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
156 AM EDT SAT APR 18 2026
KEY MESSAGES
- 2AM EDT UPDATE - SEVERE WEATHER THREAT DECREASING.
- 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 /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...FISHER
AVIATION...NWS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page