Met Office

Hurricane Isaac

Hurricane Isaac is one of 80 to 100 tropical cyclones which develop globally each year. Although many of these form and dissipate over the ocean, a number make landfall and can cause considerable damage to property and loss of life. Isaac is the ninth storm of the 2012 Atlantic season. It is only the fourth time in over 70 years that the ninth storm of the Atlantic season has formed as early as August.

Hurricane Isabel 2003What is a tropical cyclone?

A tropical cyclone is the generic term for a low pressure system over tropical or sub-tropical waters, with organised convection (i.e. thunderstorm activity) and winds at low levels circulating either anti-clockwise (in the northern hemisphere) or clockwise (in the southern hemisphere). The whole storm system may be five to six miles high and 300 to 400 miles wide, although sometimes can be even bigger. It typically moves forward at speeds of 10-15 mph, but can travel as fast as 40 mph. At its very early and weak stages it is called a 'tropical depression'. When the winds reach 39 mph it is called a 'tropical storm'. If the wind should reach 74 mph or more the tropical storm is called a 'hurricane' in the Atlantic and the north-east Pacific or a 'typhoon' in the north-west Pacific. In other parts of the world, such as the Indian Ocean and South Pacific the term 'cyclone' or 'tropical cyclone' is used.

Further information on tropical cyclones worldwide

tropical stormWhere can I see current warnings?

Regional Specialized Meteorological Centres have responsibility for the issues of tropical cyclone warnings in their area and should be used as a first source of information.

Latest warnings for current tropical cyclones

60x60_stormtrackerStormTracker

StormTracker provides a complete mapped picture of tropical storms around the globe to aid decision making, help evaluate risk and enable the comparison of past and present storms.

Further information on Met Office StormTracker

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The Met Office maintains a Twitter feed on storms which includes regular updates on latest tropical cyclones worldwide.

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Last Updated: 29 August 2012

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