836  
FXUS63 KIWX 300727  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
327 AM EDT MON JUN 30 2025  
   
KEY MESSAGES
 
 
- TWO PERIODS OF SHOWERS/STORMS ARE EXPECTED, ONE INTO THE  
MORNING HOURS AND A SECOND, LOWER CONFIDENCE CHANCE LATE  
AFTERNOON INTO THIS EVENING. HEAVY RAIN IS THE MOST LIKELY  
THREAT, BUT STRONGER STORMS THIS AFTERNOON AND EVENING COULD  
PRODUCE ISOLATED WIND DAMAGE.  
 
- DRIER AND LESS HUMID TUESDAY THROUGH EARLY FRIDAY WITH  
SEASONABLE HIGHS IN THE 80S.  
 
- A RETURN TO HOT AND HUMID CONDITIONS AS WELL AS DIURNAL  
SHOWERS/STORMS SATURDAY TO MONDAY.  
 

 
   
DISCUSSION
 
 
ISSUED AT 312 AM EDT MON JUN 30 2025  
 
A SMALL AREA OF SHOWERS AND STORMS HAS BEEN TRYING TO EXPAND ACROSS  
SW PORTIONS OF THE CWA, BUT IS STRUGGLING GIVEN THE OVERALL LACK OF  
CONVERGENCE OR STRONG FORCING. AN AREA OF SHOWERS AND STORMS WAS  
HOLDING ITS OWN AND EVEN EXPANDING SOMEWHAT ACROSS CENTRAL IN  
WITH THIS AREA WORKING NE TO IMPACTS SE PARTS OF THE FORECAST  
AREA THROUGH 15Z OR SO. HAVE WENT WITH CHC POPS IN THESE AREA  
AND SLGT CHC ELSEWHERE TO HANDLE THE POP UP ACTIVITY EXPECTED. THE  
MAIN THREAT FROM ANY OF THESE WILL BE LOCALLY HEAVY RAIN GIVEN  
COPIOUS AMOUNTS OF MOISTURE (PWATS PUSHING 2" IN SOME AREAS) AND  
OVERALL SLOW MOVEMENT. THE AREA WILL LIKELY END UP IN A LULL  
FOR CONVECTION PRIOR TO THE ARRIVAL OF A COLD FRONT AND  
SOMEWHAT STRONGER TROUGH. HOWEVER, THE FINAL COVERAGE OF THE  
FIRST ROUND OF CONVECTION AS WELL AS ANY REMNANT OUTFLOWS WILL  
DETERMINE IF WE CAN INDEED REMAIN DRY OR IF RANDOM  
SHOWERS/STORMS POP IN AN UNSTABLE (MLCAPE 1000 TO 1500 J/KG) AND  
MOST LIKELY UNCAPPED ATMOSPHERE. ANY AREAS OF WEAK CONVERGENCE  
COULD EASILY POP A FEW STORMS WITH THE THE MOST LIKELY AREAS  
LATE AM INTO EARLY AFTERNOON POSSIBLY BEING NEAR LK MI WHERE  
LAKE CONVERGENCE MAY HUG THE SHORE AND ALLOW FOR SOME  
DEVELOPMENT. CAMS ARE STRUGGLING ON EXACTLY HOW CONVECTION MAY  
UNFOLD WITH REGARDS TO TIMING, COVERAGE AND INTENSITY ALONG AND  
AHEAD OF THE COLD FRONT LEADING TO LOW CONFIDENCE IN THE FINAL  
OUTCOME. ANY LIMITED SEVERE THREAT WILL COME FROM DEVELOPMENT  
THIS AFTERNOON AND EVENING, BUT EVEN SO THE BEST DYNAMICS AND  
SHEAR LAG BEHIND THE FRONT RESULTING IN MORE OF A PULSE OR  
LOOSELY ORGANIZED MULTICELL STORM SETUP WITH LOCALLY HEAVY RAIN  
AND GUSTY WINDS THE MAIN CONCERN. AFTER COORDINATION, HAVE  
CAPPED POPS AT HIGH CHC DURING THE MOST FAVORABLE WINDOW LATE  
AFTERNOON INTO EARLY EVENING AND OPTED FOR COVERAGE WORDING  
TODAY AND THIS EVENING EVERYWHERE. BASED ON SOME MODELS TRENDS  
ON A SLOWER ARRIVAL TO THE COLD FRONT, POPS WERE ALSO SLOWED  
DOWN WRT TO THE WEST TO EAST LOWERING TREND. EVERYTHING SHOULD  
GENERALLY BE CLEAR BY 6Z TUE.  
 
TUESDAY THROUGH FRI NIGHT WILL BE SOMEWHAT LESS HUMID AND  
SEASONABLE WARM WITH HIGHS IN THE 80S AS THE OVERALL UPPER LEVEL  
TROUGH REMAINS IN PLACE. MODEL BLEND STILL PLACING SOME SLGT  
CHC POPS IN FOR THURSDAY WITH A SUBTLE DISTURBANCE. NOT REALLY  
BUYING THE SLGT CHC POPS, BUT WILL LEAVE ALONE FOR NOW. UPPER  
LEVEL RIDGING BEGINS TO BUILD FOR THE WEEKEND WITH SIGNALS OF  
590 DM OR HIGHER WORKING BACK IN WHICH WOULD YIELD HIGHS IN THE  
UPPER 80S TO AROUND 90 AND AT LEAST SOMEWHAT INCREASED HUMIDITY  
AS WELL AS DIURNAL CHANCES FOR SHOWERS AND STORMS.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
 
 
ISSUED AT 1233 AM EDT MON JUN 30 2025  
 
SHOWERS AND THUNDERSTORMS ARE DEVELOPING NORTH OF KLAF, DRIFTING  
NORTHEAST WITHIN THE WARM SECTOR OF A LOW CENTERED NEAR THE UP  
OF MICHIGAN. SPC MESOANALYSIS DEPICTS AMPLE INSTABILITY THIS  
HOUR AND ACCEPTABLE UPPER-LEVEL SUPPORT FROM A VORT LOBE  
ROTATING THROUGH CENTRAL AND SOUTHERN INDIANA. THIS OUGHT TO  
KEEP THE PROB30 EARLY THIS MORNING IN PLAY THOUGH CONFIDENCE IS  
LOW OVERALL. GREATER CONFIDENCE IN SCATTERED STORMS PASSING  
THROUGH IN THE AFTERNOON AHEAD OF AN UPPER-LEVEL TROUGH AND  
SUBSEQUENT COLD FRONT. KSBN HAS A REASONABLE OPPORTUNITY TO SEE  
TWO ROUNDS OF STORMS. MEANWHILE, THE COLD FRONTAL STORMS APPEAR  
UNLIKELY TO ARRIVE TO KFWA GIVEN A DWINDLING TS ENVIRONMENT.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...NONE.  
OH...NONE.  
MI...NONE.  
MARINE...NONE.  
 

 
 

 
 
DISCUSSION...FISHER  
AVIATION...BROWN  
 
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