503  
FXUS63 KIWX 010556  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
156 AM EDT WED JUL 1 2026  
   
KEY MESSAGES  
 
- EXTREME HEAT WARNING REMAINS IN EFFECT AREA-WIDE THROUGH  
THURSDAY EVENING. DAILY HIGHS IN THE 90S AND HEAT INDICES  
BETWEEN 100 TO 110 DEGREES ARE EXPECTED.  
 
- NEAR RECORD WARM OVERNIGHT LOWS IN THE MID 70S WILL OFFER LITTLE  
TO NO RELIEF FROM THE HEAT AT NIGHT.  
 
- HIGHS IN THE UPPER 80S TO LOW 90S FOR THE 4TH OF JULY WITH  
20-50% CHANCES FOR RAIN AND STORMS.  
 
- REMAINING WARM THROUGH EARLY NEXT WEEK WITH HIGHS IN THE 80S  
AND PERIODIC CHANCES FOR RAIN AND STORMS.  
 
 
   
DISCUSSION  
 
ISSUED AT 155 PM EDT TUE JUN 30 2026  
 
AN AMPLIFIED, DOMINANT UPPER LEVEL RIDGE WILL BRING VERY HOT AND  
HUMID CONDITIONS THROUGH AT LEAST THURSDAY, JULY 2ND. AS SURFACE  
HIGH PRESSURE BUILDS OVER THE SOUTHEAST US, SOUTHWEST FLOW INTO OUR  
AREA CONTINUES TO USHER IN VERY HUMID AIR (DEWPOINTS IN THE MID 70S)  
DUE TO A DEVELOPING CONNECTION WITH THE GULF. WITH SUCH A HUMID  
AIRMASS, IT CAN BE DIFFICULT TO ACHIEVE TEMPERATURES ABOVE THE MID  
TO UPPER 90S IN OUR FORECAST AREA. WHILE REACHING 100 DEGREES IS NOT  
OUT OF THE QUESTION ON WEDNESDAY AND/OR THURSDAY (PARTICULARLY IN NW  
OHIO), NBM PROBABILITIES ARE VERY LOW AT 15% OR LESS. AN EXTREME  
HEAT WARNING REMAINS IN EFFECT FOR THE ENTIRE FORECAST AREA THROUGH  
THURSDAY. DAYTIME HIGHS WILL BE IN THE LOW TO MID 90S EACH DAY  
THROUGH THURSDAY WITH PEAK AFTERNOON HEAT INDICES BETWEEN 100 TO 110  
DEGREES. NEAR RECORD WARM LOWS IN THE MID 70S OVER THE NEXT FEW  
NIGHTS WILL OFFER VERY LITTLE TO NO REPRIEVE FROM THE HEAT. DUE TO  
THE DURATION AND INTENSITY OF THE LATE JUNE/EARLY JULY HEATWAVE,  
HEATRISK WILL BE MAXED OUT AT MAJOR TO EXTREME ACROSS THE AREA TODAY  
THROUGH THURSDAY. DESPITE IT BEING SUMMER, WHICH IS TYPICALLY THE  
HOTTEST TIME OF YEAR FOR OUR AREA, TAKE PRECAUTIONS IN THE HEAT TO  
ENSURE YOU ARE STAYING COOL AND REDUCING RISKS FOR HEAT RELATED  
ILLNESSES!  
 
AS THE UPPER LEVEL RIDGE FLATTENS AND BEGINS TO BREAK DOWN INTO  
EARLY JULY, MODEL GUIDANCE REINTRODUCES RAIN/STORM CHANCES TO OUR  
AREA JUST IN TIME FOR THE 4TH OF JULY WEEKEND. EXACT DETAILS ARE  
MURKY AND CONFIDENCE IS VERY LOW IN EXACT TIMING/PLACEMENT OF  
RAIN/STORMS, BUT WE WILL HAVE TO MONITOR FOR COMPLEXES OF STORMS  
(MCSS) THAT RIDE THE PERIPHERY OF THE FLATTENING RIDGE. OUR 4TH OF  
JULY FORECAST CURRENTLY HAS HIGHS IN THE UPPER 80S TO LOW 90S WITH  
20-50% CHANCES FOR RAIN AND STORMS. WHILE IT MAY BE SLIGHTLY  
'COOLER' INTO EARLY NEXT WEEK WITH HIGHS IN THE 80S, THE LONG TERM  
PATTERN CONTINUES TO FAVOR ABOVE NORMAL TEMPERATURES THROUGH MID  
JULY.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/  
 
ISSUED AT 147 AM EDT WED JUL 1 2026  
 
A STRONG MID/UPPER LEVEL RIDGE PERSISTS ACROSS THE OH/TN VALLEYS  
EARLY THIS MORNING, AND THIS RIDGE AXIS WILL MOVE ONLY SLIGHTLY  
EASTWARD OVER THE NEXT 24 HOURS. WEAK SUBSIDENCE UNDER THE  
INFLUENCE OF THIS RIDGING WILL RESULT IN CONTINUED LIMITED  
AVIATION WEATHER CONCERNS THIS FORECAST CYCLE. WILL STILL BE  
MONITORING FOR POTENTIAL OF SOME LIGHT MVFR FOG/PATCHY STRATUS  
GIVEN VERY MOIST LOW LEVELS, BUT CURRENTLY EXPECTING THESE  
CONDITIONS TO BE OF LESS COVERAGE COMPARED TO YESTERDAY MORNING.  
SOUTH-SOUTHWEST WINDS WILL CONTINUE THIS FORECAST CYCLE AND  
WILL INCREASE TO 10 TO 15 KNOTS AFTER DAYBREAK. BY MID-LATE  
AFTERNOON SHORT TERM FORECAST SOUNDINGS DO INDICATE MIXING  
PROFILES TAPPING INTO SOME 15 TO 20 KNOT TOP OF BOUNDARY LAYER  
FLOW AND WILL MAINTAIN GUSTS TO AROUND 20 KNOTS IN A LIMITED  
TEMPORAL WINDOW LATE THIS AFTERNOON. DRY CONDITIONS ARE EXPECTED  
TO PERSIST WITH WEAK CIN/WEAK MID/UPPER LEVEL FORCING  
PERSISTING THROUGH THE PERIOD.  
 
 
   
IWX WATCHES/WARNINGS/ADVISORIES  
 
IN...EXTREME HEAT WARNING UNTIL 8 PM EDT /7 PM CDT/ THURSDAY FOR  
INZ005>009-012>015-017-018-020-022>027-032>034-103-104-  
116-203-204-216.  
OH...EXTREME HEAT WARNING UNTIL 8 PM EDT THURSDAY FOR OHZ001-002-  
004-005-015-016-024-025.  
MI...EXTREME HEAT WARNING UNTIL 8 PM EDT THURSDAY FOR MIZ078>081-  
177-277.  
MARINE...NONE.  
 
 
 
 
 
DISCUSSION...JOHNSON  
AVIATION...MARSILI  
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