What caused the huge bank of fog on Lake Michigan Wednesday
Here is the neat video of the fog bank rolling in.
The fog is called advection fog because warmer, more moist air advects, or blows, over the cold water of Lake Michigan. As the warm, moist air moves over the cold water, the air cools down rapidly. The cooler air can't hold the moisture it could at the former warm temperature, so condensation forms. The invisible water vapor condenses and forms a fog bank.
So any of the Great Lakes now, with their cold water, are good places for advection fog to form. Water temperatures are still in the 30s and 40s while air temperatures are warming up into the 70s and 80s and containing more moisture. The east side of Lake Michigan is especially a good place for advection fog due to the more common westerly winds.
Here is a satellite image animation of a similar fog bank.
Watch for the chance of this type of fog to form today, Sunday, or Memorial Day. The wind will turn southwesterly at some point today, and start to slowly blow warmer air across Lake Michigan. The gentle flow of wind is also a feature that helps slowly form and push the fog bank eastward in one piece.
The advection fog will be possible until the difference in temperature between the water surface and the air lessens. The water will probably have to warm up into the 60s before the chance for advection fog ends. This year, with the cold water temperatures, it could be mid-June before water temperatures warm into the 60s.
If you are at the beach and see a neat fog bank like this, please post the picture below in the comments for all to enjoy.
MLive Meteorologist Mark Torregrossa has been forecasting Michigan weather for more than 20 years. He's been chief meteorologist at three television news stations in Michigan, and he's an avid gardener and hunter. Email him at email@example.com and find him on Facebook at facebook.com/mark.torregrossa and Twitter @weathermanmark