Hurricanes

Hurricanes are an important and interesting natural hazard for children to learn. The devastation and severity of hurricanes such as Hurricane Katrina and Irene that have been reported in the news and media often fail to report how the storm is evolved, normally it's just the effects and impacts after the storm occurs.

Tropical storms are intensive, low pressure weather systems known in different parts of the world as hurricanes, cyclones, typhoons and willy- willies. They are summer storms and found in low latitudes.

Hurricanes are occur most in the Pacific Ocean and are most active in the West of the Pacific. The term applied to most storms depends on their location. Only one Hurricane has ever occurred in the South Atlantic, Hurricane Catarina (2004).

Tropical storms have three major effects: very strong winds; torrential rain; storm surges. Together these can cause loss of life, considerable damage and severe economic impacts. 

A map of where hurricanes location.

Hurricanes formation is not fully understood, but it involves the transfer of energy on a huge scale. Very moist, warm air rises rapidly form the surface of the sea. On meeting colder air high in the atmosphere it condenses to form clouds. If the surface of the sea is warm enough, the upward movement sucks in more warm air that evaporates more water and the storm builds. This more this happens the larger the source of energy and the longer the life of the storm. Strong winds are released by the process. These spiral violently upwards, driven by the rotation of the Earth. They are thrown outwards from the centre of the storm. In the centre develops an area of calm- higher temperatures and no cloud- know as the eye. 

When hurricanes travel over land however, they die due to the loss of moisture. 

A map showing where each tropical cyclone has tracked between 1851 and 2007. 

ATLANTIC: Hurricane season in the Atlantic runs from June 1 to November 30. Storms outside of these dates are not unheard of. As you can see from the graph, based on the average of 150 years of storms, activity ramps up in August, and peaks once in early September, then again in October. More statistics are available here. Persons traveling to areas near the Atlantic Basin should exercise caution during the entire Hurricane Season.

EASTERN PACIFIC: The Eastern Pacific basin's hurricane season is from May 15th to November 30th, peaking in late August or early September.

WESTERN PACIFIC: The Western Pacific basin's hurricane season is mostly from July 1 to November 30, peaking in late August or early September, though storms can occur year-round.

SOUTH PACIFIC: The South Pacific basin's hurricane season is from October 15 to May 15, reaching a peak in late February or early March.

INDIAN OCEAN: The Indian basin's hurricane season is from April 1 to December 31 for the northern Indian Ocean, and from October 15 to May 31 in the southern region.

Students would be asked to copy the diagram of the hurricane formation and label it. For higher Year groups I would ask pupils to place on their diagram the relatively high and low wind speeds, a place of calm and the point of most rapid drop of pressure.  

http://www.youtube.com/watch?v=zP4rgvu4xDE

Links: http://www.accuweather.com/en/weather-blogs/hurricanefacts/when-and-where-do-hurricanes-o/31028