Here’s the Monday PM satellite picture of Lake Michigan. Note the fog over Lake Michigan. There is also some fog over the northern part of Lake Winnebago in eastern Wisconsin. There are cumulus clouds over land areas of Lower Michigan and a line of cumulus clouds in NE Wisconsin where the west lake breeze off Green Bay meets and easterly lake breeze coming off Lake Michigan.
In West Michigan, the prevailing wind was NNE. Right at Lake Michigan, a NW lake breeze had benetrated about 8 miles inland and that 8 mile stretch was clear. However, the NW lake breeze allowed the fog over the lake to come onshore for a while.
This is the South Haven Channel at 5:33 pm on Monday (9/19/19). The visibility are pretty good at this time. Now look at a pic. from 1/2 hour later:
There was a considerable difference in visibility. Image you’re on a boat, you head onto the lake at 5:30 and start down the coast. All of a sudden you’re in the fog. Good thing we have radar, GPS and other navigation tools these days.
By the way, much cooler at Lake Michigan on Monday. The high temperature was 80° at both Grand Rapids and Muskegon Monday PM, while the high was just 68.2° at the Muskegon Channel. The South Haven beach had a high temperature of 71.4° at 10 am. The wind at 10 am was northeast – off the land. At 11 pm, the temperature had fallen to 67.8 and the wind was northwest coming off the water. At the Muskegon Beach, the lowest the relative humidity was on Monday was 86.3% and the highest (in the fog) was 99.9% at both 8 and 9 pm.