Fog This Morning

With the clouds finally clearing out toward sunset yesterday across the I-29 corridor, conditions for near perfect radiational cooling were setting in. Radiational cooling is just the atmosphere cooling down once the sun sets. Well, with clear skies and calm winds last night AND a lot of left over moisture from the several hours of mist we saw yesterday, areas of dense fog developed. This morning many areas are experiencing visibilities at or below 1/4 mile. Most of the areas effected are right down the I-29 corridor as seen in the picture below. The fog this morning was very shallow, only extending to a couple hundred feet off the ground, but very very thick in spots. This fog reminds me a lot of the type of fog that occurs in San Francisco. Here is a picture of fog they usually get in San Fran.

Notice that the fog is thick enough that you can see through it, but the high of the cloud appears to be quite small, 100-200 feet or so. I'm sure some of the areas that have some higher rolling hills in South Dakota may have experienced something very similar.

~KDLT Meteorologist Cody Matz