A nor'easter is formed in a strong extratropical cyclone, usually experiencing bombogenesis.

A low-pressure system experiencing extremely rapid intensification of the kind called "bombogenesis" brought 77 inches of snow in one day, Maine.

Explosive Cyclogenesis (also referred to as a weather bomb, meteorological bomb, explosive development, or bombogenesis) refers in a strict sense to a rapidly deepening extratropical cyclonic low-pressure area.

Bombogenesis events require a storm's central pressure to drop more than 24 millibars in 24 hours; the Great Blizzard deepened by a remarkable 40 millibars in that span of time.

An extratropical cyclone which undergoes a rapid drop in atmospheric pressure (24 millibars or more) in 24 hour period is referred to as bombogenesis, and is usually present during the formation of a nor'easter.