FZUS53 KLOT 181503
NSHLOT

Nearshore Marine Forecast
National Weather Service Chicago/Romeoville IL
1003 AM CDT Mon May 18 2026

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>742-182115-
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
1003 AM CDT Mon May 18 2026

...SEVERE THUNDERSTORM WATCH 220 IN EFFECT UNTIL 5 PM CDT THIS
AFTERNOON...

.REST OF TODAY...Southwest winds 20 to 25 kt becoming south.
Showers thunderstorms likely until early afternoon. Waves 2 to 4 
ft. 
.TONIGHT...South winds 15 to 25 kt. Slight chance of showers and 
thunderstorms in the evening, then chance of showers and 
thunderstorms overnight. Waves 2 to 4 ft. 
.TUESDAY...Southwest winds 20 to 25 kt becoming west 15 to 25 kt
in the afternoon. Chance of showers and thunderstorms. Waves 3 to
5 ft subsiding to 2 to 4 ft. A small craft advisory may be needed.
.TUESDAY NIGHT...Northwest winds 15 to 20 kt becoming north
overnight. Slight chance of showers in the evening. Waves 2 to 4 
ft. 

$$

LMZ743>745-182115-
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
1003 AM CDT Mon May 18 2026

...SEVERE THUNDERSTORM WATCH 220 IN EFFECT UNTIL 5 PM CDT THIS
AFTERNOON...

.REST OF TODAY...Southwest winds 20 to 25 kt. Showers and
thunderstorms ending early in the afternoon. Waves 2 to 4 ft.
.TONIGHT...South winds 15 to 25 kt. Slight chance of showers and 
thunderstorms in the evening, then chance of showers and 
thunderstorms overnight. Waves 2 to 4 ft. 
.TUESDAY...Southwest winds 20 to 25 kt becoming west in the
afternoon. Chance of showers and thunderstorms in the morning,
then showers likely and a chance of thunderstorms in the
afternoon. Waves 2 to 4 ft. A small craft advisory may be needed.  
.TUESDAY NIGHT...Northwest winds 15 to 20 kt becoming north
overnight. Chance of showers and slight chance of thunderstorms
in the evening. Waves 2 to 4 ft.  

$$

- Izzi