What Is a Bomb Cyclone? — In Plain Words

General information only.

The short answer

Bombogenesis is a term used by meteorologists.

It occurs when a midlatitude cyclone rapidly intensifies, or strengthens, over a 24 hour period.

Midlatitude means the latitudes between the tropics and the polar regions.

It is popularly referred to as a bomb cyclone.

So a bomb cyclone is the popular name for a storm that undergoes bombogenesis.

The strengthening is represented by a drop in millibars.

A millibar is a measurement of pressure used in meteorology.

A note about the source

NOAA's fact page on this topic is brief. This guide prints only what that page states, adding nothing from outside it. This page stays short for that reason.

How big the pressure drop must be

The intensification required to classify as bombogenesis varies by latitude.

At 60 degrees latitude, it is a drop of at least 24 millibars (24 hectopascals) over 24 hours.

At the latitude of New York City, the required pressure drop is about 17.8 millibars (17.8 hectopascals) over 24 hours.

In plain words: the closer to the poles, the bigger the drop needed.

How it can happen

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

NOAA gives this example: air over warm ocean waters.

An example from NOAA's page

The caption on NOAA's page gives this example.

Fourteen of 20 hurricane-force wind events underwent bombogenesis in the North Atlantic during the first two months of 2014.

That is the example the page itself prints.

This guide does not add other examples.

General information only.