Using Channel 2 (3.9 µm) Imagery at Night (Part II) to Identify Fog & Stratus

  Channel 2 is also useful in detecting fog or low lying stratus clouds at night .   A simple example of the use of this channel as a fog locator is shown in the following image.   There is a stratus/fog deck that lies along the West Coast of the U.S.   Using this low cloud as a reference, one may observe several inland areas that appear to show similar conditions.

  Notice, however, that in this image several features in the cloud-free regions of NV, OR and CA also seem fairly bright.   This is another case wherein a combined-channel-image product can be used to eliminate some possible ambiguities that may be present in imagery from a single GOES channel (wavelength).   See the Fog Product discussion and compare that image with this one.