Watch: What is 'Bomb cyclone'?

A powerful winter storm in which a weather system experiences a sharp drop in atmospheric pressure and intensifies rapidly, unleashing hurricane-force winds called 'Bomb cyclone'. Photograph:( WION )

Reuters New York, NY, United States Jan 05, 2018, 10.05 AM (IST)

Several bomb cyclones have made headlines in recent years and the latest one which hit northeast United States has thrown normal life out of gear.

Bombogenesis or 'Bomb cyclone' is a popular term that describes a mid-latitude cyclone that intensifies rapidly. It is a powerful winter storm in which a weather system experiences a sharp drop in atmospheric pressure and intensifies rapidly, unleashing hurricane-force winds.

The technical term is 'Explosive cyclogenesis' or 'Bombogenesis'. Bomb cyclone is a shorter way of saying it which comes from combining "bomb" with "cyclogenesis".

According to the US-based National Oceanic and Atmospheric Administration (NOAA) 'Bomb cyclone' occurs when a mid-latitude cyclone rapidly intensifies, dropping at least 24 millibars over 24 hours.

A millibar is a unit of pressure that measures the weight of the atmosphere overhead. Sea-level pressure is about 1,010 millibars.

This can happen when a cold air mass collides with a warm air mass, such as air over warm ocean waters. The formation of this rapidly strengthening weather system is a process called bombogenesis, which creates what is known as a bomb cyclone.