670
FXUS63 KIWX 070558
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
158 AM EDT SUN JUN 7 2026
KEY MESSAGES
- DAILY PERIODIC CHANCES FOR SHOWERS AND STORMS POSSIBLE THROUGH NEXT
WEEKEND, ESPECIALLY MONDAY INTO TUESDAY NIGHT WITH 60-80%
CHANCES.
- HOT AND HUMID, ESPECIALLY FROM WEDNESDAY INTO NEXT WEEKEND.
FIRST 90+ DEGREE DAY OF THE YEAR LIKELY BY LATE NEXT WEEK.
UPDATE
ISSUED AT 620 PM EDT SAT JUN 6 2026
WEAK SURFACE FRONTAL BOUNDARY SLOWLY PUSHING SOUTH THIS EVENING
AND SERVING AS IMPETUS FOR SCT STORMS. WHILE SURGING LOW LEVEL
MOISTURE IS GENERATING MLCAPE'S IN EXCESS OF 2K J/KG, OVERALL
SYNOPTIC SUPPORT FOR ASCENT IS QUICKLY DWINDLING AS MIDLEVEL
TROUGH AND EMBEDDED SHORTWAVE TO OUR NE SHIFT FURTHER EAST.
SHEAR IS MARGINAL, PARTICULARLY IN THE LOWER LEVELS AND MIDLEVEL
LAPSE RATES ARE LESS THAN 6 C/KM. UPDRAFTS WILL LIKELY CONTINUE
TO STRUGGLE IN AN ALMOST SUBSIDENT BACKGROUND ENVIRONMENT BUT
DEGREE OF INSTABILITY STILL LEADS TO CONCERNS FOR SOME ISOLATED
SEVERE STORMS CAPABLE OF HAIL AND DAMAGING WINDS THIS EVENING.
HI-RES CAM'S ALSO SHOW THIS ACTIVITY CONTINUING TO EXPAND AND
STRENGTHEN OVER THE NEXT 2-3 HOURS WITH SOME BETTER ORGANIZATION
POSSIBLE AS UPDRAFTS GROW IN SCALE. GIVEN A NEW WATCH ISSUED
FOR PORTIONS OF NORTHERN OHIO AND THE FACT THAT THE BEST
FORCING/SHEAR RESIDES THERE, WENT AHEAD AND EXPANDED THE WATCH
TO INCLUDE FOUR MORE OF OUR OHIO COUNTIES.
DISCUSSION
ISSUED AT 1226 PM EDT SAT JUN 6 2026
VISIBLE SATELLITE IMAGERY ILLUSTRATES THAT CLEARING IS ONGOING FOR
OUR FORECAST AREA AS OF MIDDAY. A COLD FRONT CURRENTLY EXTENDS FROM
ROCKFORD, IL OVER LAKE MICHIGAN TO GRAND HAVEN, MI. OUT AHEAD OF IT,
AN OUTFLOW BOUNDARY IS NOTED IN THE WPC SURFACE ANALYSIS OVER
LA PORTE AND BERRIEN COUNTIES. LARGE SCALE ASCENT AMIDST AN
UNSTABLE ENVIRONMENT WILL ALLOW FOR SCATTERED DISCRETE STORMS TO
DEVELOP ALONG THAT REMNANT OUTFLOW BOUNDARY AS THE COLD FRONT
PUSHES SOUTHWARD. SEVERE WEATHER IS MOST LIKELY TODAY DURING
PEAK HEATING HOURS (3 PM EDT AND ONWARDS). CONCERNS YESTERDAY
AND OVERNIGHT WERE THAT COVERAGE AND INTENSITY OF STORMS WOULD
DEPEND ON HOW THE MORNING EVOLVED. THE ENVIRONMENT HAS RECOVERED
FAVORABLY BEHIND MORNING CONVECTION WITH 2500 J/KG OF SBCAPE
NOTED IN NORTHWEST INDIANA WITH AN UNCAPPED ENVIRONMENT. 0- 6KM
SHEAR HAS INCREASED AS WELL TO AROUND 35-40 KTS. HOWEVER, IT IS
IMPORTANT TO NOTE THAT LAPSE RATES ARE MEAGER IN BOTH THE LOW
AND MID LEVELS AT ONLY AROUND 6-6.5 C/KM. RECENT SURFACE OBSERVATIONS
SHOW THAT INCREASED MOISTURE HAS WORKED INTO THE AREA WITH
DEWPOINTS AROUND 70 AND INCREASED WAA DUE TO SOUTHWESTERLY WINDS.
INCREASED MOISTURE COMBINES WITH DAYTIME HEATING (HIGHS IN THE
LOW TO MID 80S TODAY) TO SUPPORT EXPLOSIVE SBCAPE OF UP TO 3000
J/KG. NO TOWERING CUMULUS CAN BE SEEN ON SATELLITE YET, BUT
CONVECTIVE INITIATION SHOULD OCCUR IN THE NEXT FEW HOURS MAINLY
ALONG AND SOUTH OF I-80/I-90. A SLIGHT RISK (LEVEL 2 OF 5) FOR
SEVERE WEATHER IS IN PLACE ACROSS NORTHWEST OHIO AND NORTHERN
INDIANA, MAINLY ALONG AND SOUTH OF US 30 WHERE THE GREATEST
COVERAGE OF STORMS IS EXPECTED. DESPITE LAPSE RATES NOT BEING AS
STEEP AS PREVIOUSLY FORECAST, SCATTERED INSTANCES OF DAMAGING
WIND AND HAIL ARE STILL EXPECTED TODAY ALONG AND SOUTH OF US 30
GIVEN AFOREMENTIONED FAVORABLE SHEAR AND INSTABILITY. WITH PWATS
AROUND 1.5", EVEN SUB-SEVERE STORMS WILL LIKELY BE EFFICIENT
RAINFALL PRODUCERS TODAY WITH RAINFALL RATES IN EXCESS OF 1"/HR.
THE AFOREMENTIONED COLD FRONT WILL STALL OVER OUR FORECAST AREA
(MOST LIKELY THE US 24 CORRIDOR) OVERNIGHT INTO SUNDAY MORNING,
RESULTING IN LINGERING SHOWERS AND STORMS. AS INSTABILITY BUILDS
DURING THE DAYTIME, CHANCES FOR PRECIPITATION CREEP BACK UP IN THE
VICINITY OF THE STALLED FRONT, MAINLY ALONG AND SOUTH OF US 30. HIGH
PRESSURE CENTERED OVER ONTARIO WILL KEEP LOWER MICHIGAN MAINLY DRY
TOMORROW. HIGHS WILL BE IN THE LOW TO MID 80S.
THE STATIONARY FRONT THEN IS PULLED NORTHWARD AS A DEVELOPING LOW
PRESSURE SYSTEM LIFTS INTO THE UPPER MIDWEST INTO WISCONSIN ON
MONDAY. THIS FRONTAL SYSTEM WILL BRING RENEWED CHANCES FOR RAIN AND
STORMS AS HIGH AS 60-80% AREA-WIDE, MAINLY MONDAY AFTERNOON THROUGH
TUESDAY.
IT WILL THEN BECOME HOT AND HUMID, ESPECIALLY FROM WEDNESDAY ONWARDS
INTO NEXT WEEKEND. AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE CENTRAL
CONUS, SUMMER-LIKE TEMPERATURES IN THE UPPER 80S TO LOW 90S ARE
ANTICIPATED. THE FIRST 90+ DEGREE DAY IS LIKELY FOR MANY LOCATIONS
BY THE END OF THE WEEK. HEAT INDICES MAY APPROACH 100 DEGREES DURING
PEAK HEATING HOURS. DEPENDING ON THE AMPLITUDE AND CENTER OF
THE UPPER LEVEL RIDGE, THERE COULD BE DAILY PERIODIC CHANCES FOR
RAIN/STORMS BY MID TO LATE IN THE WEEK. FOR NOW, HAVE KEPT NBM
LOW CHANCES (20-40% EACH DAY) FOR WEDNESDAY AND BEYOND IN THE
FORECAST DUE TO LOW CONFIDENCE.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 149 AM EDT SUN JUN 7 2026
PREDOMINANTLY VFR CONDITIONS AT THE TERMINALS THIS PERIOD, WITH
MOST CONVECTION ALONG A FRONTAL BOUNDARY TO THE SOUTH OF THE
TERMINALS. MVFR/IFR SEEMS MORE LIKELY AT KFWA WITH LINGERING LOW
LEVEL MOISTURE AND NEARLY CALM WINDS, ESPECIALLY IF THE CLOUD
COVER IS LIMITED TO SCATTERED WHERE WE CAN RADIATE A LITTLE BIT.
JUST NORTH KGWB IS REPORTING 1SM VISIBILITY, AND KSMD HAD A
BRIEF DIP TO 1/4SM BEFORE RETURNING TO 10SM. SOME OF THE
GUIDANCE DOES TANK KFWA TO 1/4-1/2SM VIS, BUT DIDN'T FEEL
CONFIDENT ENOUGH TO GO THAT LOW YET. WILL MONITOR AND AMEND AS
NEEDED IN THE COMING HOURS IF TRENDS SEEM TO BE DIPPING BELOW
IFR.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
UPDATE...AGD
DISCUSSION...JOHNSON
AVIATION...MCD
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