689  
FXUS63 KIWX 020436  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
1236 AM EDT SUN AUG 2 2026  
   
KEY MESSAGES  
 
- DANGEROUS SWIMMING CONDITIONS ARE EXPECTED AT LAKE MICHIGAN  
BEACHES ALONG THE LA PORTE COUNTY, IN AND BERRIEN COUNTY, MI  
SHORELINE. LIFE-THREATENING WAVES AND CURRENTS ARE EXPECTED.  
A BEACH HAZARDS STATEMENT IS IN EFFECT. FOR DETAILS, VISIT  
WWW.WEATHER.GOV/GREATLAKES/BEACHHAZARDS  
 
- CONDITIONS DRY OUT FROM NORTHWEST TO SOUTHEAST LATER SUNDAY  
INTO SUNDAY NIGHT.  
 
 
   
DISCUSSION  
 
ISSUED AT 321 PM EDT SAT AUG 1 2026  
 
AFTER AN INITIAL BAND OF RAIN THAT SWEPT FROM WEST TO EAST ACROSS  
THE AREA THIS MORNING, MOST OF THE LOCAL AREA HAS REMAINED DRY  
THROUGH MID AFTERNOON DUE TO THE INFLUENCE OF A MID LEVEL DRY SLOT.  
VORTICITY ADVECTION ASSOCIATED WITH MID/UPPER LEVEL LOW ACROSS  
CENTRAL IL IS BEGINNING TO PUSH EASTWARD. AN INSTABILITY AXIS OF  
1000-1500 J/KG SBCAPE IS CONTINUING TO NUDGE NORTHWARD IN MODEST  
SOUTHERLY FLOW REGIME DOWNSTREAM IF THIS IL DISTURBANCE AND SHOULD  
ALLOW FOR CONTINUED SHOWER AND STORM DEVELOPMENT ACROSS NORTHERN  
INDIANA OVER THE NEXT SEVERAL HOURS. A POCKET OF STRONGER EFFECTIVE  
SHEAR ON THE ORDER OF 30-35 KNOTS MAY END UP JUST SKIRTING FAR  
SOUTH/SOUTHEAST PORTIONS OF THE FORECAST AREA ACROSS FAR NE IN/NW OH  
EARLY THIS EVENING WHICH IS ALSO COINCIDENT WITH POCKET OF 100-150 0-  
1KM SRH. SOME ISOLATED WIND THREAT IS POSSIBLE IN A BRIEF WINDOW  
LATE THIS AFTERNOON/EARLY EVENING FAR SOUTH/SOUTHEAST, BUT CURRENTLY  
EXPECTING GREATER POTENTIAL OF ISOLATED-SCATTERED SEVERE STORMS TO  
REMAIN ACROSS CENTRAL IN.  
 
THE POTENTIAL OF HEAVY RAINFALL WILL LIKELY BE THE PRIMARY IMPACT  
LOCALLY. AN IMPRESSIVE LOW LEVEL THETA-E RIDGE THAT SHIFTED INTO THE  
AREA THIS MORNING IS ACQUIRING MORE OF A WEST-NORTHWEST TO  
EAST-SOUTHEAST ORIENTATION IN RESPONSE TO INDUCED CYCLONIC FLOW  
FROM UPSTREAM IL MID/UPPER LEVEL LOW. THIS SHOULD CREATE  
FAVORABLE DEEP MOISTURE PROFILES AND EFFICIENT WARM RAIN  
PROCESSES TONIGHT INTO EARLY SUNDAY. SHOWERS AND EMBEDDED  
STORMS SHOULD FILL IN ACROSS NORTHERN IN THROUGH EARLY EVENING  
ESPECIALLY ALONG AND SOUTH OF US 24, WITH AN EVENTUAL PIVOT IN  
ORIENTATION OF MOST FAVORED RAIN SHOWER AXIS TO SW-NE ORIENTED  
FROM WEST CENTRAL IN TO AS POSSIBLY AS FAR EAST AS NW OHIO LATE  
EVENING/EARLY OVERNIGHT AS DEFORMATION FORCING BEGINS TO SHARPEN  
UP. THIS SETUP SHOULD PROVIDE FAVORABLE LOW LEVEL MOISTURE  
CONVERGENCE FOR A RELATIVELY EXTENDED DURATION TONIGHT INTO  
EARLY SUNDAY MORNING.  
 
EARLIER TODAY, SOME HIGHLY EFFICIENT RAINFALL ACCUMULATION WAS NOTED  
ACROSS NW INDIANA WITH THE LEADING BAND OF SHOWERS, WITH SOME  
LOCATIONS PICKING UP A QUICK 1 TO 2 INCHES. EARLIER TODAY, DID GO  
AHEAD AND ISSUE A FLOOD WATCH FOR POTENTIAL OF FLASH FLOODING/AREAL  
FLOODING FOR ALL OF IN COUNTIES FROM 21Z THIS AFTERNOON TO 21Z  
FRIDAY, ALTHOUGH GREATEST POTENTIAL OF HEAVY RAIN IS ROUGHLY  
FROM EARLY THIS EVENING THROUGH MID MORNING SUNDAY. GIVEN THE  
ABOVE EVOLUTION, THE FAR NORTH/NORTHWEST PORTIONS OF THE FLOOD  
WATCH MAY BE AT A BIT LOWER CONFIDENCE LEVEL FOR FLOODING RAINS  
GIVEN INCREASING SIGNALS THAT THE FAVORED DEFORMATION FORCING  
AXIS MAY RESIDE FROM SOUTHWEST PORTIONS OF THE FORECAST AREA  
THROUGH FAR NE IN. DID EXCLUDE NW OH COUNTIES AS PART OF THE  
INITIAL FLOOD WATCH ISSUANCE, BUT AN EASTWARD EXTENSION OF THE  
WATCH MAY BE NEEDED AT SOME POINT. ONE MITIGATING FACTOR TO  
FLOOD POTENTIAL TONIGHT COULD BE RELATIVELY DRY ANTECEDENT  
CONDITIONS, BUT IF HIGHER RAINFALL RATES ARE ABLE TO ANCHOR IN  
DEFORMATION REGION TONIGHT, THIS WILL STILL LIKELY LEAD TO SOME  
FLOODING ISSUES FOR A PORTION OF THE AREA.  
 
STRENGTH OF DEFORMATION SHOULD TEND TO WEAKEN SUNDAY  
AFTERNOON/EVENING AS RESPONSIBLE MID/UPPER LEVEL TROUGH BEGINS TO  
BECOME ATTENUATED AND MORE SHEARED. CONDITIONS SHOULD DRY OUT FROM  
NE TO SE LATER SUNDAY AFTERNOON INTO SUNDAY EVENING WITH A QUIETER  
WEATHER PATTERN THROUGH TUESDAY AS A LONGWAVE MID/UPPER LEVEL RIDGE  
SHIFTS ACROSS ONTARIO AND THE WESTERN GREAT LAKES. AN ACTIVE SERIES  
OF PACIFIC WAVES ACROSS SOUTH CENTRAL CANADA/DAKOTAS WILL DAMPEN  
THIS RIDGE MIDDLE OF THE WEEK WITH LOCAL AREA POSSIBLY IN A FAVORED  
THETA-E GRADIENT REGION FOR PERIODIC WAVES IN WEST-NORTHWEST UPPER  
FLOW FOR ADDITIONAL SHOWER/STORM CHANCES THROUGH MUCH OF THE LONG  
TERM PERIOD.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z MONDAY/  
 
ISSUED AT 1235 AM EDT SUN AUG 2 2026  
 
BETTER LOW LEVEL MOISTURE CONTINUES TO SLOWLY PIVOT NORTHWARD AS  
POTENT MID/UPPER LEVEL LOW BEGINS TO OPEN UP AND DRIFT FURTHER  
EAST. STILL EXPECT A PERIOD OF IFR CEILINGS AT KFWA, BUT THE  
RISK OF THUNDERSTORMS CONTINUES TO DROP. AT KSBN, EXPECT JUST  
SOME TRANSIENT MVFR CEILINGS WITH POTENTIAL FOR VFR TO HOLD  
THROUGH MUCH OF THE MORNING. BOTH TERMINALS WILL SEE A RETURN TO  
VFR BY SUNDAY AFTERNOON (EARLIEST AT KSBN) WITH TRANQUIL WEATHER  
TO END THE PERIOD.  
 
 
   
IWX WATCHES/WARNINGS/ADVISORIES  
 
IN...FLOOD WATCH THROUGH THIS AFTERNOON FOR INZ007>009-017-018-020-  
022>027-032>034.  
BEACH HAZARDS STATEMENT THROUGH MONDAY MORNING FOR INZ103.  
OH...NONE.  
MI...BEACH HAZARDS STATEMENT THROUGH MONDAY MORNING FOR MIZ277.  
BEACH HAZARDS STATEMENT FROM THIS AFTERNOON THROUGH MONDAY  
MORNING FOR MIZ177.  
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT MONDAY FOR LMZ043-046.  
 
 
 
 
 
DISCUSSION...MARSILI  
AVIATION...AGD  
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