441
FXUS63 KIWX 041831
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
231 PM EDT THU JUN 4 2026
KEY MESSAGES
- 40-60% CHANCES FOR SHOWERS AND THUNDERSTORMS FRIDAY AFTERNOON
AND EVENING. ISOLATED SEVERE WEATHER POSSIBLE WITH DAMAGING
WIND AND LARGE HAIL AS THE MAIN THREATS. LOW CONFIDENCE.
- KEEP AN EYE ON THE WEATHER IF YOU HAVE OUTDOOR PLANS ON
SATURDAY! INCREASINGLY HUMID WITH 60-80% CHANCES FOR SHOWERS
AND THUNDERSTORMS SATURDAY AFTERNOON AND EVENING. THERE IS A
SLIGHT RISK FOR SEVERE WEATHER (LEVEL 2 OF 5) WITH DAMAGING
WINDS AND LARGE HAIL AS THE MAIN THREATS. MEDIUM CONFIDENCE.
- DRY AND WARM EARLY NEXT WEEK WITH CONTINUED HIGHS IN THE MID
TO UPPER 80S.
DISCUSSION
ISSUED AT 230 PM EDT THU JUN 4 2026
QUIET, DRY WEATHER PERSISTS TODAY. WITH HIGH PRESSURE HAVING DRIFTED
FROM BEING OVERHEAD YESTERDAY TO NOW OVER THE MID ATLANTIC TODAY,
HIGH CLOUDS ARE DRIFTING IN FROM THE WEST AND WINDS HAVE TURNED
SOUTHERLY AHEAD OF A BIG PATTERN SHIFT IN THE COMING DAYS. SOUTHERLY
SURFACE FLOW IS AIDING IN INCREASED WAA, WITH HIGHS EXPECTED TO BE
IN THE MID TO UPPER 80S THIS AFTERNOON. A TIGHTENING PRESSURE
GRADIENT WILL ALLOW FOR GUSTS UP TO 20 MPH THIS AFTERNOON.
A MID LEVEL TROUGH WILL RIDE THE EDGE OF THE UPPER LEVEL RIDGE
CENTERED OVER THE CENTRAL CONUS ON FRIDAY, BRINGING OUR FIRST OF
SEVERAL OPPORTUNITIES FOR RAIN IN AT LEAST 7-10 DAYS. AS THIS TROUGH
MOVES THROUGH ON FRIDAY AFTERNOON AND EVENING, CHANCES FOR RAIN AND
STORMS INCREASE TO 40-60%. SOME MODELS HAVE STORMS CLIPPING THE
INDIANA-MICHIGAN STATE LINE AS EARLY AS 15-18Z TOMORROW, WHILE
OTHERS HOLD OFF IN FAVOR OF A 21-00Z START TIME. WITH BETTER
MOISTURE NOT ARRIVING INTO OUR AREA UNTIL LATER IN THE DAY
(DEWPOINTS 55-60), I LEAN MORE IN THE FAVOR OF THE LATER TIMEFRAME
BUT WE WILL ALSO HAVE TO MONITOR AND SEE WHAT DEVELOPS IN ILLINOIS
FRIDAY MORNING AND IF IT CLIPS OUR NORTHERN COUNTIES IN THE EARLY
AFTERNOON. SPC DOES HAVE A MARGINAL RISK FOR SEVERE WEATHER (LEVEL 1
OF 5) ALONG AND NORTH OF US 30 ON FRIDAY, ALTHOUGH CONFIDENCE IN
SEVERE WEATHER OCCURING IS LOW. GIVEN A FAIRLY UNIDIRECTIONAL
VERTICAL WIND PROFILE, 0-6KM SHEAR WILL ONLY BE ABOUT 20 KTS. WITH
WEAKER SHEAR, THE FAVORED STORM MODE WILL BE MULTICELL CLUSTERS OR
LINE SEGMENTS. MODERATE DCAPE OF AROUND 500-700 J/KG AND STEEP LOW
LEVEL LAPSE RATES OF 8-9 C/KM WILL SUPPORT ISOLATED INSTANCES OF
DAMAGING WINDS AND HAIL. WITH PWATS AROUND 1.5 TO 2", EVEN IF STORM
CLUSTERS ARE NOT SEVERE, THEY WILL LIKELY BE EFFICIENT RAINFALL
PRODUCERS WITH RAINFALL RATES IN EXCESS OF 1"/HR.
KEEP AN EYE ON THE WEATHER IF YOU HAVE OUTDOOR PLANS ON SATURDAY!
AHEAD OF AN APPROACHING COLD FRONT, STRONG TO SEVERE STORMS WILL BE
POSSIBLE SATURDAY AFTERNOON AND EVENING. OUR AREA WILL BE WELL INTO
THE WARM SECTOR SATURDAY WITH BREEZY SOUTHWESTERLY WINDS; DEWPOINTS
WILL INCREASE TO THE UPPER 60S AND MAYBE EVEN LOW 70S IN RESPONSE TO
A STRONG SOUTHWEST LLJ RAMPING UP FRIDAY EVENING AND INTO SATURDAY.
INCREASED MOISTURE COMBINES WITH DAYTIME HEATING (HIGHS IN THE LOW
TO MID 80S) TO SUPPORT SBCAPE OF UP TO 2500 J/KG. HOW MUCH
INSTABILITY WE GET WILL BE HIGHLY CONDITIONAL ON THE AMOUNT OF
CLEARING THAT OCCURS SATURDAY MORNING AND EARLY AFTERNOON. SOME
MODELS KEEP LINGERING RAIN/STORMS/CLOUDS ACROSS OUR AREA SATURDAY
MORNING, WHICH WOULD LIMIT HOW UNSTABLE THE ENVIRONMENT CAN BECOME.
NEVERTHELESS, SOME AMOUNT OF DESTABILIZATION SHOULD OCCUR SATURDAY
AFTERNOON AFTERNOON AFTER 18Z, WITH CHANCES FOR STRONG TO SEVERE
STORMS HIGHEST BETWEEN 18Z-03Z. A SLIGHT RISK (LEVEL 2 OF 5) FOR
SEVERE WEATHER IS IN PLACE ACROSS NORTHWEST OHIO, WITH A MARGINAL
RISK (LEVEL 1 OF 5) FOR THE REST OF THE FORECAST AREA. SEVERE
POTENTIAL IS GREATEST IN NW OHIO BECAUSE THIS AREA WILL HAVE THE
LONGEST TIME TO HEAT UP AND DESTABILIZE SATURDAY AS THE COLD FRONT
TAKES ITS TIME MOVING IN FROM NORTHWEST TO SOUTHEAST. CONFIDENCE IS
MEDIUM IN SEVERE WEATHER OCCURING (GIVEN MORNING UNCERTAINTY) BUT
THE ENVIRONMENT WILL BE MORE FAVORABLE THAN FRIDAY. STEEP LOW LEVEL
LAPSE RATES OF 9C/KM AND 0-6KM SHEAR OF 35-40 KTS WILL SUPPORT
DAMAGING WINDS AND LARGE HAIL AS THE MAIN THREATS.
IT WILL BE DRY AGAIN AS HIGH PRESSURE BUILDS IN ON SUNDAY AND MONDAY
ACROSS THE GREAT LAKES. SUMMER-LIKE TEMPERATURES IN THE MID TO UPPER
80S PERSIST THROUGHOUT ALL OF NEXT WEEK WITH ADDITIONAL DAILY
PERIODIC CHANCES FOR RAIN/STORMS BY MIDWEEK.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 130 PM EDT THU JUN 4 2026
HIGH PRESSURE GIVES WAY TO AN INCOMING FRONT LATE IN THE
PERIOD. A FEW GUSTS THIS AFTERNOON NEAR 20 KNOTS FROM MODEST
LOW-LEVEL MIXING. WIND LESS THAN 10 KNOTS TONIGHT INCREASES
AFTER 16Z WITH A TIGHTENING PRESSURE GRADIENT AND CHANCE FOR
-TSRA AT KSBN.
IWX WATCHES/WARNINGS/ADVISORIES
IN...AIR QUALITY ALERT UNTIL MIDNIGHT EDT /11 PM CDT/ TONIGHT FOR
INZ005>009-012>015-017-018-020-022>027-032>034-103-104-
116-203-204-216.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...JOHNSON
AVIATION...BROWN
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