What are the primary types of fog that pilots should recognize?

The primary types of fog that pilots should recognize include radiation, advection, upslope, evaporation, ice, and frontal fog. Each type of fog has unique formation processes and characteristics relevant to aviation safety.

Radiation fog forms when the ground loses heat rapidly overnight, cooling the air directly above it to the dew point. This type commonly occurs in clear, calm nights and can create low visibility conditions.

Advection fog develops when warm, moist air moves over a cooler surface, leading to cooling and condensation. This type is prevalent in coastal areas where warm air from the ocean meets cooler land.

Upslope fog occurs when air is forced to ascend along a slope or hill, which cools the air adiabatically, helping it reach saturation and form fog. This is critical for pilots to recognize when flying in mountainous regions.

Evaporation fog, also known as steam fog, forms when cold air moves over warm water, causing the water to evaporate and subsequently condense in the cold air above. This can create sudden visibility issues.

Ice fog is a specific form found in very cold temperatures, where supercooled water vapor freezes into tiny ice crystals, which also leads to reduced visibility and hazardous flying conditions.

Frontal fog typically forms along weather fronts