There was a dramatic change in the temperature along the Lake Michigan shoreline from Manistee south Tuesday into Wednesday.
Temperatures on the beaches of Lake Michigan from Ludington south crashed over a 24 hour period as gusty north winds Tuesday created what is know as upwelling, allowing colder water from the deeper parts of Lake Michigan to make it to the surface.
Basically, strong north winds Tuesday followed the passage of a cold front. Those winds raced down the length of Lake Michigan pushing warmer water near the shallower shoreline out into the lake where it mixed with colder water. This displacement of warmer water near the Lake Michigan shoreline allowed for much colder water at greater depths to "upwell" to the surface leading to a massive and quick drop in water temperatures near the lakeshore.
For instance, the buoy offshore of Ludington had a water temperature of 71F at 4:00 p.m. Tuesday evening. By 8:00 a.m. Wednesday morning, the water temperature had plunged to 42F! That's a 29F degree drop in a 16 hour period, almost two degrees/hour.
Even at the beaches a dramatic drop in temperature was noted. At Ludington State Park, the water temperature was 72F Tuesday morning and had dipped to 58F by Wednesday morning. Temperature changes this dramatic in the Great Lakes typically take weeks if not longer to occur.
In the meantime, on land it looks chilly as well. High temperatures this upcoming weekend will struggle to get into the mid-60's on cold north winds setting up one of the coldest weekends that we ever see in the month of July.