What is a bomb cyclone?

Freezing temperatures and wild weather combine to create a bomb storm.

Heavy storms, wind and precipitation define a bomb cyclone.

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What is a bomb cyclone?

Meteorologists define a bomb cyclone as a winter storm transformed by explosive cyclogenesis.

A bomb storm occurs when the central barometric pressure of a mid-latitude storm falls at a rate of one millibar per hour for at least 24 hours.

The process by which central air pressure falls is called explosive cyclogenesis.

Cyclogenesis is considered explosive because air pressure drops to one millibar from normal air pressure, which is 1,010 millibars.

Where does the name come from?

The term “bomb cyclone” was first coined in the 1940s.

The Weather Channel’s Mike Bettes told CBS News, “It’s called a bomb cyclone because a negative pressure (or cyclone) undergoes ‘bomb arcing,’ which refers to the rapid rate at which the negative pressure develops.

“In winter you can experience both intense snowfall and extreme winds.

“It usually leads to very dangerous driving conditions with blowing and drifting snow and poor visibility.

“Airlines often cancel flights because conditions are too risky to fly.”

He added, “High winds can often cause widespread power outages.”

What happens during a cyclone?

It occurs when a mid-latitude cyclone rapidly intensifies and drops by at least 24 millibars — one millibar is a measure of atmospheric pressure — in 24 hours.

This can happen when a cold air mass collides with a warm air mass.

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When drastically different air masses collide, it’s a recipe for a bomb storm.

An example is when cool air moves over warm ocean water.

The formation of this rapidly strengthening weather system is a process called bombbogenesis, which creates what is known as a bomb cyclone.

Where do bomb storms occur?

Bomb hurricanes are most common on warm-water coasts.

The warm water creates a strong temperature gradient from its surface to the atmosphere directly above.