The extended cold weather we've been experiencing has caused the ice on Lake Michigan to expand in coverage. Below is a loop of MODIS satellite imagery (3 images) showing the state of the ice coverage from December 28th, 2013 (no ice), Jan 23rd, 2014 (first clear image with ice apparent) and Jan 28th showing the maximum ice coverage so far this season. This imagery was captured by the Terra & Aqua Polar Orbiter Satellites. Check out SSECs MODIS browser here. Here is an interesting CIMSS Satellite Blog about the ice.
A frequent question we get is, "When was the last time Lake Michigan froze over completely?" It appears we've only been tracking ice coverage for about the last 40 years. In that time, the mid to late 1970s were very cold and there was a lot of ice. But, more recently, 1994 was a very cold winter and we saw Lake Michigan nearly freeze over completely. Check out this site for historical ice coverage maps.
Here is a comparison of ice coverage since 1980 for Jan 28th each year from Environment Canada (essentially the National Weather Service of Canada)
So our current Great Lakes ice coverage continues to be more than double the median value since 1980.
The image below (from Environment Canada) shows the current year weekly ice coverage for all of the Great Lakes versus the median value (green line) since 1980. You'll notice that we are more than double the median value for the week around Jan 28th, and that the current value is actually about 20% higher than the typical peak of ice coverage that occurs around March 12th each year.
The following is a chart (from Environment Canada) shows the departure from normal ice cover.