266
FLUS43 KLOT 180904
HWOLOT
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
404 AM CDT FRI SEP 18 2026
ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-190915-
WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-DUPAGE-
LA SALLE-KENDALL-GRUNDY-KANKAKEE-LIVINGSTON-IROQUOIS-FORD-
NORTHERN COOK-CENTRAL COOK-SOUTHERN COOK-NORTHERN WILL-
SOUTHERN WILL-EASTERN WILL-LAKE IN-PORTER-NEWTON-JASPER-BENTON-
404 AM CDT FRI SEP 18 2026 /504 AM EDT FRI SEP 18 2026/
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
ILLINOIS...NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
DAY ONE
TODAY AND TONIGHT.
WEATHER HAZARDS EXPECTED...
ELEVATED THUNDERSTORM RISK.
ELEVATED FLOODING RISK.
HIGH SWIM RISK LAKE MICHIGAN BEACHES.
DISCUSSION...
PERIODS OF HEAVY RAIN AND SCATTERED THUNDERSTORMS ARE EXPECTED
LATE TONIGHT. LOCALIZED FLASH FLOODING WILL BE POSSIBLE WHERE
HEAVY RAINS PERSIST OVER THE SAME AREAS.
HIGH WAVES WILL CREATE DANGEROUS SWIMMING CONDITIONS AT LAKE
MICHIGAN BEACHES IN NORTHEAST ILLINOIS.
DAYS TWO THROUGH SEVEN
SATURDAY THROUGH THURSDAY.
SATURDAY...
ELEVATED FLOODING RISK.
ELEVATED THUNDERSTORM RISK...WITH AN ASSOCIATED:
LEVEL 1 OF 5 SEVERE THUNDERSTORM RISK.
HIGH SWIM RISK LAKE MICHIGAN BEACHES.
SUNDAY...
ELEVATED FLOODING RISK.
LIMITED THUNDERSTORM RISK.
HIGH SWIM RISK LAKE MICHIGAN BEACHES.
MONDAY...
LIMITED FLOODING RISK.
LIMITED THUNDERSTORM RISK.
HIGH SWIM RISK LAKE MICHIGAN BEACHES.
TUESDAY...
HIGH SWIM RISK LAKE MICHIGAN BEACHES.
DISCUSSION...
PERIODS OF HEAVY RAIN AND SCATTERED THUNDERSTORMS ARE EXPECTED
THROUGH SUNDAY NIGHT. LOCALIZED FLASH FLOODING AND LOCAL RIVER
RISES ARE POSSIBLE.
PERSISTENT NORTHEAST WINDS WILL MAINTAIN HIGH WAVES AND
DANGEROUS SWIMMING CONDITIONS AT LAKE MICHIGAN BEACHES IN
NORTHEAST ILLINOIS AND NORTHWEST INDIANA THROUGH EARLY NEXT
WEEK.
SPOTTER INFORMATION STATEMENT
SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.
GENERAL STORM MOTION OF THE DAY:
MOVING TOWARD THE SOUTHEAST AT 25 TO 35 MPH.
LMZ740>745-190915-
WINTHROP HARBOR TO WILMETTE HARBOR IL-
WILMETTE HARBOR TO NORTHERLY ISLAND IL-
NORTHERLY ISLAND TO CALUMET HARBOR IL-
CALUMET HARBOR IL TO GARY IN-GARY TO BURNS HARBOR IN-
BURNS HARBOR TO MICHIGAN CITY IN-
404 AM CDT FRI SEP 18 2026
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE ILLINOIS
NEARSHORE WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE
WATERS OF LAKE MICHIGAN.
DAY ONE
TODAY AND TONIGHT.
WEATHER HAZARDS EXPECTED...
HAZARDOUS CONDITIONS FOR SMALL CRAFT.
ELEVATED THUNDERSTORM RISK.
DAYS TWO THROUGH SEVEN
SATURDAY THROUGH THURSDAY.
SATURDAY...
HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY.
ELEVATED THUNDERSTORM RISK.
SUNDAY AND MONDAY...
HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY.
LIMITED THUNDERSTORM RISK.
TUESDAY AND WEDNESDAY...
HAZARDOUS CONDITIONS FOR SMALL CRAFT ARE LIKELY.
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