Lansing, Mich. (WLNS) – Upwelling is not a common word one would hear when watching the local weather report. In Michigan, the word becomes slightly more common because it affects the Great Lakes along with other bodies of water.
Upwelling is when warm, less dense water is pushed away from the shoreline. Water has to replace the warm water at the top that has been transported away. Cold, more dense water from lower in the body of water rises, and takes the place of the warm water that was pushed away. Winds from the north, northeast and east can lead to an upwelling event on the eastern side of Lake Michigan.
The first weekend in August, some beaches in west Michigan were seeing water temperatures crash from the mid 70s to the 50s and 60s. Water temperatures that cold can become dangerous for swimming, as the body can go into cold shock within one minute, incapacitation in 10 minutes and hypothermia in one hour.
The waters along the shoreline of Lake Michigan are expected to warm back up, but it will take a few days. Whether an upwelling event has occurred or not, be sure to check water temperatures before jumping.