Two vital components are needed to create a Hurricane, warm air and warm water usually around 80 degrees, which is why hurricanes are frequent in tropical areas. A hurricane, which usually starts as a thunder storm, gathers its power and speed travelling across the ocean, taking in the warm air and moisture from the surface of the sea and releasing cooler air which creates the increasingly powerful spiralling wind.
Generally the hurricane season peaks in late summer. The Atlantic hurricane season begins in June and ends in November, while the Eastern Pacific hurricane season begins in May and ends November.
The National hurricane centre monitors the progress of storms and escalates thunderstorms to a hurricane based on 3 stages of the wind speed.
Tropical Depression – Wind speeds of less than 38 miles per hour
Tropical Storm – Wind speeds between 39 mph – 73mph
Hurricane – Winds speeds 74mph or more
Once a storm is officially considered a hurricane, the hurricanes sustained wind force is then rated on a scale of 1 -5 to estimate its severity and expected destruction to property and life.
The Saffir-Simpson Hurricane wind scale taken from the National Hurricane Center is structured as follows -
Hurricane Category 1 – Wind speeds of 74mph-95mph
Dangerous winds and will cause some damage – Minor damage to roofs, trees and power lines.
Hurricane Category 2 – Wind speeds of 96mph-110mph
Extremely dangerous winds and will cause extensive damage – Major roof damage, trees and power lines.
Hurricane Category 3 – Wind speeds of 111mph-129mph
Major hurricane, devastating damage will take place – Major damage to house, removal of roof decking, coastal flooding and inland flooding, trees uprooted and electricity and water may be unavailable for days to weeks.
Hurricane Category 4 – Wind speeds of 130mph-156mph
Major Hurricane, Horrific damage will take place – House may lose roofs and exterior walls, uprooted trees. Power outages may last weeks or months and most areas inhabitable for weeks or months.
Hurricane Category 5 – Wind speeds of 157mph +
Major Hurricane, catastrophic damage – Homes and buildings destroyed with irreparable damage, trees uprooted, coastal and inland flooding, most areas uninhabitable for weeks or months.
A number of recorded hurricanes have exceeded sustained winds of 180mph, suggesting that a Category 6 should be introduced. However, according to meteorologist and co-developer of the Saffir-Simpson Hurricane Scale, Robert Simpson, the scale is used to measure the destruction to man-made structures and any winds of 155mph or more, will cause serious damage to buildings no matter how well engineered they are.