A bomb cyclone will hit parts of the US - what is it?
A bomb cyclone is expected to hit the US East Coast this weekend, bringing heavy snow, strong winds and the risk of coastal flooding. Also known as bombogenesis, this type of storm forms when a cold air mass collides with a warm air mass, rapidly intensifying the system.
The most intense cyclonic storm to impact the United States was the 1993 "Storm of the Century."
BBC meteorologist Simon King looks at what a bomb cyclone is and its possible impact.




















