FZUS53 KLOT 190901 NSHLOT Nearshore Marine Forecast National Weather Service Chicago/Romeoville IL 401 AM CDT Tue Aug 19 2025 For waters within five nautical miles of shore on Lake Michigan Waves are provided as a range of significant wave heights, which is the average of the highest 1/3 of the waves, along with the average height of the highest 10 percent of the waves which will occasionally be encountered. LMZ740>742-192130- Winthrop Harbor to Wilmette Harbor IL- Wilmette Harbor to Northerly Island IL- Northerly Island to Calumet Harbor IL- 401 AM CDT Tue Aug 19 2025 ...SMALL CRAFT ADVISORY IN EFFECT FROM LATE TONIGHT THROUGH LATE WEDNESDAY NIGHT... .EARLY THIS MORNING...Southwest winds around 10 kt becoming west. Chance of showers and thunderstorms. Waves around 1 ft. .TODAY...Northwest winds 10 to 20 kt becoming north around midday. Slight chance of showers in the morning. Waves around 1 ft building to 2 to 4 ft. .TONIGHT...North winds 15 to 20 kt. A chance of sprinkles, mainly after midnight. Waves 2 to 4 ft building to 3 to 6 ft occasionally to 8 ft. .WEDNESDAY...Northeast winds 15 to 25 kt. A chance of sprinkles in the morning. Waves 3 to 6 ft occasionally to 8 ft. .WEDNESDAY NIGHT...North winds 15 to 25 kt becoming northeast 10 to 20 kt overnight. Mostly clear. Waves 3 to 6 ft occasionally to 8 ft. $$ LMZ743>745-192130- Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN- Burns Harbor to Michigan City IN- 401 AM CDT Tue Aug 19 2025 ...SMALL CRAFT ADVISORY IN EFFECT FROM LATE TONIGHT THROUGH LATE WEDNESDAY NIGHT... .EARLY THIS MORNING...Southeast winds 10 to 15 kt becoming southwest. Showers and thunderstorms likely. Waves around 1 ft. .TODAY...Southwest winds 10 to 15 kt becoming north 15 to 20 kt in the afternoon. Chance of showers and thunderstorms in the morning. Waves 1 to 2 ft building to 2 to 4 ft. .TONIGHT...North winds 15 to 20 kt. A chance of sprinkles after midnight. Waves 3 to 5 ft building to 3 to 6 ft occasionally to 8 ft. .WEDNESDAY...North winds 15 to 25 kt. A chance of sprinkles in the morning. Waves 3 to 6 ft occasionally to 8 ft. .WEDNESDAY NIGHT...North winds 15 to 25 kt becoming northeast and diminishing to 10 to 15 kt overnight. Mostly clear. Waves 3 to 6 ft occasionally to 8 ft. $$ RC