What is an ocean storm?

Ocean storm: also called a marine storm, refers to any storm that takes place upon or near the ocean. Such storms can involve strong winds and heavy precipitation. Depending upon the strength, they may be called hurricanes, tropical storms, storm depressions or extratropical cyclones.

There are numerous types of ocean storms. Some happen within the tropics and others outside the tropics. Some last for a few hours, while others last for several weeks or even months. Some happen very frequently, while others are very rare. Some form over the open ocean, while others start over land and gradually move over the ocean.

* In the North Atlantic Ocean, the storm-producing season lasts throughout the year, but most storms form between May and November, with the peak period in August and September.

* The most common Atlantic tropical cyclones are tropical depressions and tropical storms.

* The most powerful and devastating Atlantic tropical cyclones are hurricanes.

These classifications are based on wind speeds:

* Tropical depression: a low pressure system with a closed circulation and maximum sustained surface wind speeds of up to 63 km/h (39 miles per hour).

* Tropical storm: a low pressure system with a closed circulation and maximum sustained surface wind speeds between 64 and 118 km/h (39 and 73 miles).

* Hurricane: a low pressure system with a closed circulation and maximum sustained surface wind speeds of more than 118 km/h (73 miles per hour).

When these storms affect continental areas the results can be devastating, as they often occur with little warning and cause massive damage to human infrastructure.