Tuesday, June 19, 2007

how storms are named?


in 2001 it was named in alphabetical oreder like this :Allison,Barry, Chanthal , Dean, Erin etc.

The World Meteorological Organization uses six lists in rotation.

Tropical Cyclone Formation ?

Theyare formed in 4 major phases.

The first step occurs when a collection of small thuerstorms forms over the tropics. The hurricanes that threaten the East and Gulf coasts of the United States, for example, are the product of storms that first form over the coast of western Africa and head west across the Atlantic Ocean. The cyclones that strike East Asia and Australia, on the other hand, form over the central Pacific. Tropical cyclones emerge in these regions, between 8° and 20° latitude, because of the high humidity, light winds, and warm sea surface temperatures present in these locations. Cyclones and hurricanes can only form when the ocean water is around 80°F (26.5°C) or higher, and these conditions are only common during certain months of the year.

June to October is often referred to as "Hurricane Season" in the northern hemisphere. The opposite situation occurs in the southern hemisphere since the tropical waters off Australia.


THE second stage of development IS called a tropical depression once the sustained wind speed within the storm reaches 23 mph (37 km/h). The air inside the depression becomes less dense and rises tens of thousands of feet above the ocean surface. As its altitude increases, the air cools causing more water vapor to condense and release its heat, which draws in yet more air to rise upward. This process repeats itself again and again causing the temperature at the center of the storm to continually increase and driving the surface pressure even lower.This process becomes a chain reaction that pulls hot, humid air from the surface of the ocean up to high altitude where the air becomes cold and water vapor condenses into thick clouds.

If the sustained wind speed increases to 39 mph (63 km/h), the tropical depression enters the third stage of development called a tropical storm.

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