Snow cover is often easy to identify on visible imagery due to the appearance of unfrozen rivers and topographical features such as mountain ranges (snow cover also remains stationary in an image animation, while cloud features tend to move and evolve). However, on each of the two days shown there were several patches of low cloud (stratiform cloud comprised of water droplets) over and near the areas of significant snow cover. These low clouds show up as darker (warmer) features on the shortwave IR imagery due to the enhanced reflectivity of the liquid cloud droplets (in addition to the IR channel 2 sensitivity to reflected solar radiation off the cloud tops). The snow cover appears slightly brighter (colder) than the surrounding snow-free terrain since snow (as well as ice cloud) is a poor reflector of the 3.9 micrometer wavelength radiation detected by IR channel 2.

27 October -- GOES-8 visible Animations: Java | QuickTime

27 October -- GOES-8 IR channel 2 Animations: Java | QuickTime

Interactive dual-image comparison (visible and shortwave IR)