National Weather Service Chicago/Romeoville IL
9:00 PM Monday July 24.
waves are provided as a range of significant wave heights, which is the average of the highest 1/3 of the wave, along with the average height of the highest 10% of the waves which will occasionally be encountered. synopsis, high pressure of 30.1 inches over lake michigan will slowly move east reaching the eastern great lakes by tuesday night. low pressure of 29.5 inches will move east to james bay on wednesday, with a trailing trough moving over the lake wednesday night. low pressure around 29.7 inches is expected to develop on this trough by late wednesday night, shifting a cold front south across the lake by thursday morning. high pressure of 30.1 inches will follow, building over the lake for the weekend.