These storms are often mistaken for hurricanes because they share many common characteristics and can spawn hurricane force winds. A bomb cyclone is an extratropical area of low pressure in which the central barometric pressure drops at least 24 millibars in 24 hours. Some storms have intensified as rapidly as 60 millibars in a 24 hour period.
Some bomb cyclones are hybrid storms, which share some other characteristics with hurricanes.
Even though bomb cyclones sometimes share characteristics with hurricanes, it is important to note that they are not hurricanes as the two storms also have several differences. Bomb cyclones have cold air and fronts. Cold air rapidly weakens hurricanes while it is an essential ingredient for bomb cyclones. Bomb cyclones form under strong upper-level winds. Strong high altitude winds associated with intense upper-level disturbances would destroy a hurricane, but are a necessity for bomb cyclone development, also known as bombagenesis.