From Glossary of Meteorology
Fog associated with frontal zones and frontal passages.
It is usually divided into three types: warm-front prefrontal fog; cold-front post-frontal fog; and frontal-passage fog. The first two types are a result of rain falling into cold stable air and raising the dewpoint temperature. Frontal-passage fog can result from the "mixing of warm and cold air masses in the frontal zone" or by "sudden cooling of air over moist ground."
Byers, H. R. 1944. General Meteorology. 518–519.
George, J. J. 1951. Compendium of Meteorology. 1183–1184, 1187.