This animation of GOES-12 3.9 micrometer IR (channel 02) images shows the motion of a bank of fog/stratus along the East Coast on 03 April 2007. Note how the portion of the fog/stratus that moves southward over the colder offshore waters (darker blue to violet enhancement) stays intact, and appears to be "channeled" between the coastline and the boundary of the warmer Gulf Stream waters. The brightness temperature of the fog/stratus apears to warm dramatically after sunrise (11-12 UTC), due to the fact that the 3.9 micrometer IR channel is also sensitive to solar reflection off of supercooled water droplet cloud features.