Hurricane

A Hurricane is a Type of Cyclone that, like all others, develop from a tropical wave or low.

A hurricane first starts its life as either a Tropical or Subtropical Depression, with winds as high as less than 39 mph.



Depressions when they form require a water temperature of at least 75+°F and and wind-sheer less than 35 knots. And they need little or no dry entrainment. At this point, the cyclone only gets a number, its storm organization is moderate to heavy. Depressions have a minimum low pressure of 1015 milibars and a maximum of 995 milibars. They have a weak outflow at this point as well.

Depressions have formed off of Africa, Mexico, the US coast, even in the bay of campeche and the gulf of Mexico.

Depressions normally cause little or no damage, but can cause some flooding. Subtropical Depressions are storms with cold core temperatures or little convection.



As the depression strengthens, with more favorable conditions, it becomes a Tropical Storm or a Subtropical Storm with winds ranging between 39 and 73 mph. At this stage, The Cyclone revives a Name, Letters ranging from A to Z except for Q, U, X and Y. And at this stage, the storm has increased in organization.

And in order for a cyclone to strengthen to a Storm, it requires Wind-Sheer of less than 25-30 knots, waters equal to or warmer than 75-80°F and little or no Dry air.

The outflow of a Tropical Storm is strong then that of a Depression, Not necessarily enough to shear other storms. Tropical Storms also have pressures between 1010 milibars and 975 milibars.

Tropical Storms can at times form an Eye even if winds are less than 74 mph.

Storms can also produce little or no damage but at times have been known to cause major damage and major flooding. For example- Tropical Storm Allison of 2001 caused up-to $4 to 6 billion in damage from flooding.

A Subtropical Storm is a cold core storm that can from in favorable and unfavorable conditions, but these storms can at times not only generate storm force winds but Hurricane winds as well, they either don't have much convection or have wider wind-fields than Purely Tropical Storms.



As organization and Strengthening continues, the storm gets upgraded to a Hurricane with winds of 74+ mph. At this point, it would only take 37+ mph before it becomes a Major Hurricane

Hurricanes require a water temperature of more than 80°F, wind-sheer of less than 20-25 knots and little or no dry air.

Hurricanes between Category-1 and Category-2 tend to have large or small eyes, or even dis-organised eyes, and cloud covered.

Hurricanes have pressures between 1000 milibars and 950 milibars. They can produce surge up-to 10-15 feet.

Hurricanes tend to produce serious damage and flooding.



As the storm organizes and intensifies still, its becomes a Major Hurricane with winds greater than 111 mph.

Major Hurricanes also require a water temperature of greater 80°F, wind shear of less than 15-20 knots and little or no dry air.

Major Hurricanes range from Category-3 to Category-5. At this point, a hurricane's outflow is so strong, it can shear other on coming storms.

A major hurricane has a pressure between 995 and 870 milibars. And a Major hurricane`s eye can range between a mile and 150 miles wide. A major hurricane can cause serious damage and flooding, and can had surge over 15 feet.

Major hurricanes be as wide as the island of Puerto Rico or as large as the U.S.

The strongest, largest and deepest storm known was Typhoon Tip of 1979. With winds of 195 mph and a pressure of 870 milibars.