246
FXUS63 KIWX 300550
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
150 AM EDT SUN AUG 30 2026
KEY MESSAGES
- MOST LOCATIONS WILL BE DRY INTO THE MIDDLE OF NEXT WEEK. A FEW
SHOWERS ARE POSSIBLE ACROSS FAR NORTHERN INDIANA AND SOUTHERN
LOWER MICHIGAN TONIGHT INTO SUNDAY.
- HEAT AND HUMIDITY INCREASES INTO NEXT WEEK WITH AFTERNOON HEAT INDICES
EXPECTED TO REACH WELL INTO THE 90S FOR MANY. HEAT INDICES
MAY APPROACH 100 DEGREES FOR PORTIONS OF THE AREA TUESDAY AND
WEDNESDAY AFTERNOONS.
- SLIGHTLY BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS ARRIVE
FOR THE SECOND HALF OF THE UPCOMING WEEK.
DISCUSSION
ISSUED AT 145 PM EDT SAT AUG 29 2026
INITIAL AREA OF SHOWERS AND THUNDERSTORMS IN EASTERN IA MOVED
EAST AND HAS BEEN FALLING APART AS IT BECOMES ORPHANED FROM THE
BETTER LOW LEVEL FLOW (850 MB WINDS UP TO 50 KTS AT TIMES).
ADDITIONAL CONVECTION HAS BEEN FORMING BEHIND IT, GENERALLY
DRIFTING IN A SE DIRECTION. OVER TIME CAMS SHOW THIS AREA
WEAKENING AS THE LLJ RELAXES SOME AND WAVE DEPARTS. THE SAME
CAMS SEEM TO SUGGEST NEW DEVELOP NOT IN IA BUT CLOSER TO THE
AREA (EASTERN IL/SW MI/NW IN) LATER TONIGHT AS THE LLJ BEGINS TO
SHIFT SOMEWHAT AND WEAK ISENTROPIC LIFT OCCURS AHEAD OF A
SLIGHTLY BETTER MOISTURE FLUX. WILL CONTINUE WITH SLGT CHC TO
CHC POPS INTO SUNDAY MORNING, BUT THE VAST MAJORITY OF LOCATIONS
WILL LIKELY REMAIN DRY.
THEREAFTER OUR RAIN CHANCES WILL BE DICTATED BY THE POSITION OF
THE EDGE OF A BUILDING UPPER LEVEL RIDGE FROM THE SOUTH. SADLY,
MUCH LIKE PAST WEEKS WE WILL BE ON THE NORTHERN FRINGE OF THE
RIDGE WHICH COULD BRING SOME CHANCES FOR SHOWERS AND STORMS MID
TO LATE WEEK AS AN UPPER LEVEL LOW TRIES TO EDGE IN BUT IS
LIKELY DEFLECTED NE. ONE DIFFERENCE THIS TIME AROUND MAY BE THE
AXIS OF BEST PRECIP ENDS UP NORTH AND WE END UP ON THE WARMER
AND MORE HUMID SIDE, ESPECIALLY TUESDAY AND WEDNESDAY. SIGNALS
POINT TOWARDS HIGHS QUITE LIKELY AT OR ABOVE 90 DEGREES WITH
AFTERNOON HEAT INDICES IN THE UPPER 90S TO AROUND 100. SOMETHING
TO KEEP IN THE BACK OF YOUR MIND AND MONITOR FOR NOW.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 150 AM EDT SUN AUG 30 2026
STRONG LOW/MID LEVEL MOISTURE ADVECTION WILL CONTINUE ACROSS THE
MID MS RIVER VALLEY INTO PORTIONS OF THE SOUTHERN GREAT LAKES
FOR THE REMAINDER OF THE NIGHT INTO SUNDAY AFTERNOON. A SUBTLE
SHORT WAVE TOPPING THE UPPER LEVEL RIDGE IS EXPECTED TO RAPIDLY
SHIFT EAST FROM SOUTHERN MN/IA THROUGH THIS MORNING WHICH COULD
AUGMENT ADVECTIVE FORCING ASSOCIATED WITH A SOUTHWESTERLY LOW
LEVEL JET. ELEVATED INSTABILITY RESULTING FROM THIS ELEVATED
MOISTURE ADVECTION SHOULD RESULT IN ADDITIONAL
ISOLATED/SCATTERED SHOWER DEVELOPMENT THROUGH 18Z WITH BEST
CHANCES OF SHOWERS AT KSBN. WHILE SOME LOW PROBABILITY OF
THUNDER WILL EXIST THROUGH EARLY THIS AFTERNOON AT KSBN,
CONFIDENCE IN OCCURRENCE IS TOO LOW FOR INCLUSION WITH THE 06Z
TAFS GIVEN LIMITED MAGNITUDE OF THE ELEVATED INSTABILITY.
STRONGER ADVECTIVE FORCING SHOULD WANE LATER THIS AFTERNOON AND
EVENING, WITH ADDITIONAL SLIGHT CHANCES OF SHOWERS PERSISTING
ACROSS FAR NORTHERN INDIANA. OTHERWISE TODAY, PRIMARILY VFR
CONDITIONS EXPECTED OUTSIDE OF ANY HEAVIER BRIEF SHOWER ACROSS
NW IN, WITH SOUTHWEST WINDS GUSTING AS HIGH AS 15 TO 20 KNOTS AT
KSBN WHERE SFC GRADIENT IS EXPECTED TO BE A BIT STRONGER.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...FISHER
AVIATION...MARSILI
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