Wind is another factor that influences the formation of fog. Table 1-8 shows the various
wind conditions and whether or not they are favorable for the formation of fog:
Wind
Fog Formation Potential
Calm
Fog will form but is generally very shallow.
Light
With dust-laden air, is ideal for fog formation. Produces deep layers
of fog.
Moderately
Tends to keep fog from forming as it circulates the air too rapidly for
strong
fog producing conditions to exist.
Strong
Will dissipate fog that has already formed.
Table 1-8 -- Wind conditions
Air Mass Fog
Fog is divided into two classes: air mass fog and frontal fog. We will discuss each class
separately since there are different requirements that govern the formation of each.
Air mass fog occurs within a given air mass and is formed when the layer of air closest
to the earth's surface is cooled by contact with a colder surface below.
There are four types of air mass fog (see Table 1-9). Each type gets its name from the
particular manner in which air is cooled to the dew point. The four types are radiation
fog, advection fog, upslope fog, and steam fog.
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