NWS Marine Forecast



 Hazardous marine condition(s):
 Special Marine Warning
 Marine Weather Statement
 Hazardous Weather Outlook
   LMZ740>742-190915-  Winthrop Harbor to Wilmette Harbor IL-  Wilmette Harbor to Northerly Island IL-  Northerly Island to Calumet Harbor IL-  911 PM CDT Tue Aug 18 2026    REST OF TONIGHT  Southwest winds 10 to 20 kt becoming northwest  around 10 kt late. Showers with thunderstorms likely late in the  evening, then slight chance of showers after midnight. Waves 1 to  2 ft. Higher winds and waves in and near thunderstorms, including  a brief gusty northwest wind shift up to 30 kt.  WEDNESDAY  North winds around 10 kt becoming northeast in the  afternoon. Mostly cloudy. Waves 1 to 2 ft.  WEDNESDAY NIGHT  East winds around 10 kt becoming northeast.  Mostly cloudy in the evening then clearing. Waves 1 to 2 ft.  THURSDAY  East winds around 5 kt becoming southeast in the  afternoon. Sunny. Waves around 1 ft.    $$