February 15, 2000
Satellite loop over a 1.5 hour period of time. 

 

The best way to determine cloud cover from ice cover is to run a loop or animation of a number of images.  As you can see here, the clouds move, the ice does not.  It is easy to pick out the ice cover over Lake Erie, but over Lake Ontario it is a bit more elusive.  Notice, however the northeast corner of the lake where there is significant ice cover.