133
FXUS63 KIWX 130515
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
115 AM EDT WED AUG 13 2025
KEY MESSAGES
- SCATTERED TO NUMEROUS SHOWERS AND STORMS LATE THIS AFTERNOON
INTO THIS EVENING. THE STRONGEST STORMS WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAINFALL AND ISOLATED WIND GUSTS IN
EXCESS OF 50 MPH.
- A FEW SHOWERS AND STORMS MAY REDEVELOP ALONG A COLD FRONT WEDNESDAY
AFTERNOON, BEST CHANCES (20-40%) ALONG AND SOUTH OF US 24.
- HEAT AND HUMIDITY RETURNS THIS WEEKEND WITH PEAK AFTERNOON HEAT
INDICES WELL INTO THE 90S.
DISCUSSION
ISSUED AT 135 PM EDT TUE AUG 12 2025
A MOIST AND DIURNALLY DESTABILIZING THERMODYNAMIC ENVIRONMENT
CONTINUES TO APPEAR SUPPORTIVE OF SCATTERED TO NUMEROUS SHOWERS AND
STORMS AS WEAK HEIGHT FALLS/TROUGHING OVERSPREAD. AREAS OF
CONVERGENCE AND INSTABILITY GRADIENTS WILL BE THE LOCATIONS WHERE
CONVECTION LIKELY FIRES. LATEST REGIONAL MOSAIC RADAR AND HRRR
TRENDS HINT AT WIDELY SCATTERED CONVECTION FOR MOST THIS AFTERNOON
INTO THIS EVENING NEAR BOUNDARIES AND WITH SUBTLE MID LEVEL
IMPULSES, WITH A MORE ORGANIZED CLUSTER OF STORMS LIKELY TRACKING
EAST INTO AREAS MAINLY WEST OF INTERSTATE 69 LATE THIS
AFTERNOON INTO THIS EVENING IN ADVANCE OF A COLD FRONT. LOCALLY
HEAVY RAINFALL APPEARS TO BE THE PRIMARY THREAT GIVEN THE DEEP
MOIST CLOUD LAYER, THOUGH MORE ROBUST, PRECIPITATION LOADED
CORES COULD ALSO PRODUCE ISOLATED WIND GUSTS IN EXCESS OF 50
MPH GIVEN A FAVORABLE DCAPE PROFILE.
AN UPPER TROUGH TRACKING EAST THROUGH THE GREAT LAKES WILL FORCE THE
PRIMARY COLD FRONT SOUTHEAST INTO THE AREA OVERNIGHT INTO WEDNESDAY
MORNING, WITH THIS BOUNDARY POTENTIALLY GETTING HUNG UP NEAR OR JUST
OF THE US 24 CORRIDOR BY PEAK HEATING TOMORROW. LINGERING HUMIDITY
AND LOW CHANCES FOR A FEW SHOWERS/STORMS POSSIBLE IF THE BOUNDARY
LAYER SUFFICIENTLY RECOVERS. REGARDLESS, LOSS OF DEEPER MOISTURE AND
FORCING PRECLUDES ANYTHING MORE THAN A 20-30% POP, WITH DRIER AIR
FINALLY FILTERING WITH PLEASANT WEATHER THURSDAY INTO FRIDAY.
THE HEAT AND HUMIDITY THAT HAS BEEN A COMMON THEME THIS SUMMER
RETURNS THIS WEEKEND AS THE PERSISTENT SUBTROPICAL RIDGE FLEXES
NORTHEASTWARD TOWARD THE LOWER GREAT LAKES. MODELS DIFFER ON HOW
QUICKLY THIS FEATURE RETROGRADES BACK WEST AS A SERIES OF RING OF
FIRE CONVECTIVE COMPLEXES ROLL THROUGH ITS NORTHERN FRINGES. THESE
MCS'S WILL NEED MONITORING, PARTICULARLY SUNDAY INTO EARLY NEXT WEEK.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 110 AM EDT WED AUG 13 2025
THE SHOWERS AND STORMS YESTERDAY EVENING AND A DRY OVERNIGHT IS
IN STORE. CURRENTLY, WINDS ARE OUT OF THE SOUTHWEST AND WILL
GRADUALLY SHIFT TO BECOME MORE WESTERLY IN THE NEXT FEW HOURS.
WITH LEFTOVER GROUND MOISTURE FROM RAIN AND LIGHT WINDS, DENSE
FOG MAY DEVELOP THIS MORNING BETWEEN 09-13Z WITH MVFR CEILINGS
AND POTENTIAL FOR IFR CEILINGS AS LOW AS 1000 FT. WILL CONTINUE
TO MONITOR FOR FOG DEVELOPMENT BUT THE NBM DOES HAVE 40-50%
PROBABILITIES OF MVFR VISIBILITIES AROUND DAYBREAK. WINDS THEN
SHIFT AGAIN DURING THE DAYTIME FROM WEST TO NORTHWEST BY THE
LATE MORNING/EARLY AFTERNOON. A FEW SHOWERS AND STORMS ARE
POSSIBLE IN THE VICINITY OF KFWA TOMORROW (MOST OF THE ACTIVITY
WILL BE ALONG AND SOUTH OF US 24 AS THE COLD FRONT COMES
THROUGH) BUT HAVE OPTED TO MAINTAIN A DRY TAF FOR KFWA FOR NOW
UNTIL CONFIDENCE INCREASES. KSBN WILL REMAIN DRY.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...STEINWEDEL
AVIATION...JOHNSON
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