Hurricane Sandy was 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. Sandy was the 10th hurricane of the 2012 Atlantic hurricane season.
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
Our YouTube video explains what are hurricanes and how they are formed.
Hurricane Sandy initially impacted upon Jamaica, Cuba, Haiti and the Bahamas bringing flooding and claiming more than 70 lives in the Caribbean. Having crossed the open waters of the Atlantic for a couple of days it turned left and made landfall near Atlantic City, New Jersey at about 00 UTC 30 October 2012. A storm surge of near 14 feet brought extensive flooding and winds of up to 90 mph produced much structural damage across several US states. Over 110 people are thought to have lost their lives in the USA.
This is the second time in two years that New Jersey and New York has been impacted by a tropical system. in 2011 Hurricane Irene travelled up the east coast of the US and made landfall with winds of 65 mph in Brooklyn, New York. However, Sandy had a much larger impact than Irene due to it's larger size, stronger winds and greater storm surge. Prior to 2011 other hurricanes which have impacted this part of the US east coast were Hurricane Bob in 1991, Hurricane Gloria in 1985 and the notorious hurricane of 1938 which claimed near to 800 lives in the USA.
The National Hurricane Center (NHC) and the US Federal Emergency Management Agency (FEMA) provide warnings and advice to those who are potentially at risk from hurricanes affecting the USA. The Met Office routinely supplies predictions of hurricane tracks from its global forecast model to NHC which it uses along with guidance from other models in the production of its forecasts and guidance.
StormTracker provides a mapped picture of tropical cyclones (tropical storms, hurricanes, typhoons) around the globe with access to track history and six-day forecast tracks for current tropical cyclones from the Met Office Unified Model and latest observed cloud cover (infra-red and visible satellite) and sea surface temperature.Further information on Met Office StormTracker
The Met Office maintains a Twitter feed on storms which includes regular updates on latest tropical cyclones worldwide.
Last updated: 7 November 2013