010
FXUS63 KIWX 221718
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
118 PM EDT TUE JUL 22 2025
KEY MESSAGES
- HOT AND HUMID CONDITIONS EXPECTED WEDNESDAY AND THURSDAY WITH
HEAT INDICES 95 TO 102 WEDNESDAY (HIGHEST WEST) AND 100 TO 105
THURSDAY ACROSS THE ENTIRE AREA.
- SHOWER AND THUNDERSTORM CHANCES RETURN FRIDAY INTO SATURDAY,
LIKELY LIMITING HEAT IMPACTS. HEAVY RAIN AND LOCALLY GUSTY
WINDS WOULD BE THE MAIN THREATS.
DISCUSSION
ISSUED AT 352 AM EDT TUE JUL 22 2025
CONFIDENCE IS HIGH IN UPPER 80S TO LOW 90S ARRIVING WED/THU.
CONFIDENCE LOWERS WRT HOW FAST HIGHER DEWPOINTS BEGIN TO ADVECT INTO
THE AREA. LOW TO MID 70 DEWPOINTS COULD STRUGGLE TO ARRIVE IN FAR
WESTERN AREAS TILL CLOSER TO THE 18-21Z WINDOW AND PROGRESS EAST
OVERNIGHT. SOME MODELS STILL SHOWING MID TO UPPER 70 DEWPOINTS BY
THURSDAY, BUT WORRIED THAT MAY BE A TOUCH TOO HIGH EVEN WITH
EVAPOTRANSPIRATION WELL UNDERWAY. MUCH DISCUSSION TOOK PLACE WITH
SURROUNDING OFFICES ON HEAT HEADLINES WITH THE EASTERN EXTENT OF
"AROUND 100 DEGREES" FOR HEAT INDICES IN QUESTION WEDNESDAY. HAVE
HOISTED A HEAT ADVISORY FOR THE WESTERN 2 TIERS OF COUNTIES FROM 18Z
WED TO 00Z THU. THURSDAY STILL APPEARS TO BE THE DAY WITH THE
GREATEST CONCERN AS DEWPOINTS SHOULD BE IN THE LOW 70S AND HIGHS
NEAR/ABOVE 90. CONFIDENCE IS HIGH ON ADVISORY CRITERIA BEING MET,
NOT AS HIGH FOR WARNING LEVEL. CONSENSUS WAS TO JUST HANDLE WED
FOR NOW.
PRIOR TO THURSDAY EVENING, UPPER LEVEL RIDGING WILL KEEP ANY SHOWERS
AND STORMS WELL NORTH OF THE AREA. HOWEVER, MODEL CONSENSUS
BEGINNING TO HONE IN ON FRONTAL BOUNDARY DIVING SOUTH INTO N/NW
PARTS OF THE AREA LATE THU EVENING INTO THE OVERNIGHT HOURS BEFORE
STALLING OUT SOMEWHERE IN THE AREA FOR FRI/FRI NIGHT. MODEL BLEND
HAS INTRODUCED LIKELY POPS 06Z-12Z FRI, WHICH MAY BE OVERDONE BUT
WITH INCREASING SIGNALS WILL LEAVE THOSE ALONE. MOST ACTIVE PERIOD
STILL APPEARS TO BE FRI AFTERNOON/EVENING WITH PROXIMITY OF THE
BOUNDARY AND SEVERAL WEAK DISTURBANCES AIDING IN DEVELOPMENT. THE
MIXTURE OF CLOUDS AND PRECIP WILL LIKELY KEEP TEMPS IN CHECK,
LIMITING ANY CONCERNS FOR HEAT ADVISORIES. ADDITIONAL SHOWERS
AND STORMS ARE POSSIBLE SAT/SAT NIGHT WITH CHC POPS HANDLING
THINGS AT THIS POINT. MAIN THREATS WITH THE STORMS IN THE FRI-
SAT PERIOD WILL BE HEAVY RAIN AND MAYBE SOME LOCALLY GUSTY WINDS
WITH THE OVERALL CONCERN FOR SEVERE WEATHER LOOKING LOW AT THIS
POINT.
THE UPPER LEVEL RIDGE BEGINS TO BUILD AGAIN, BUT THIS TIME THE MAIN
RIDGE AXIS WILL EXIST TO OUR WEST WITH THE REGION ON THE NE
PERIPHERY OF THE RIDGE WITH WEAK DISTURBANCES MOVING THROUGH THE
FLOW THAT COULD BRING SOME SHOWER/STORMS CHANCES BY MON NIGHT INTO
TUESDAY.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 113 PM EDT TUE JUL 22 2025
BREEZY TODAY THROUGH 00Z WED FOR KSBN WITH SOUTHEASTERLY GUSTS
UP TO 18 KTS. OTHERWISE...VFR CONDITIONS FOR BOTH TAF SITES
THROUGH THIS TAF PERIOD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...HEAT ADVISORY FROM 2 PM EDT /1 PM CDT/ TO 8 PM EDT /7 PM CDT/
WEDNESDAY FOR INZ012>015-020-022-103-104-203-204.
OH...NONE.
MI...HEAT ADVISORY FROM 2 PM TO 8 PM EDT WEDNESDAY FOR MIZ078-177-
277.
MARINE...NONE.
DISCUSSION...FISHER
AVIATION...ANDERSEN
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