166
FZUS53 KLOT 180900
NSHLOT

Nearshore Marine Forecast
National Weather Service Chicago/Romeoville IL
400 AM CDT Mon Aug 18 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>742-181515-
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
400 AM CDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 10 AM CDT THIS MORNING...

.TODAY...Southeast winds 15 to 25 kt diminishing to 10 to 15 kt
this afternoon. Slight chance of showers and thunderstorms in the
morning, then scattered showers and thunderstorms in the
afternoon. Waves 3 to 6 ft occasionally to 8 ft subsiding to 1 to
3 ft.
.TONIGHT...Southeast winds around 10 kt becoming south overnight.
Numerous showers and thunderstorms in the evening, then chance of
showers and thunderstorms overnight. Waves 1 to 2 ft.
.TUESDAY...Southwest winds around 10 kt becoming northeast in the
afternoon. Chance of showers and thunderstorms in the morning,
then chance of showers and slight chance of thunderstorms in the
afternoon. Waves 1 to 2 ft.
.TUESDAY NIGHT...Northeast winds around 10 kt becoming north 15
to 20 kt. Mostly cloudy. Waves 1 to 2 ft building to 3 to 5 ft.

$$

LMZ743>745-181515-
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
400 AM CDT Mon Aug 18 2025

.TODAY...Southeast winds 15 to 20 kt diminishing to 5 to 10 kt.
Slight chance of showers and thunderstorms in the morning, then
scattered showers and thunderstorms in the afternoon. Waves 2 to
4 ft subsiding to around 1 ft.
.TONIGHT...Southeast winds 5 to 10 kt becoming south 10 to 15 kt.
Numerous showers and thunderstorms in the evening, then chance of
showers and thunderstorms overnight. Waves around 1 ft.
.TUESDAY...Southwest winds 10 to 15 kt becoming north in the
afternoon. Chance of showers and thunderstorms in the morning,
then slight chance of showers and thunderstorms in the afternoon.
Waves around 1 ft.
.TUESDAY NIGHT...North winds around 10 kt increasing to 15 to 20
kt late. Partly cloudy in the evening, then becoming mostly
cloudy. Waves 1 to 2 ft building to 2 to 4 ft.

$$

RC