TYPHOON HINNAMNOR

Typhoon

A typhoon is a mature tropical cyclone. These are called hurricanes when they develop over the North Atlantic, Central north Pacific, and eastern North Pacific, these rotating storms are known as cyclones when they form over the south Pacific and the Indian Ocean, and typhoons when they develop in the Northwest Pacific.

Rated on the five-point Saffir –Simpson scale based on wind speed, hurricanes are considered major when they reach category 3. A category 5 storm can deliver wind speeds of more than 253 kilometres an hour.

The Atlantic Ocean's hurricane season peaks from mid–August to late October and averages five to six hurricanes per year. While cyclones on the northern Indian Ocean typically form between April and December with peak storm activity around May and November.

HOW ARE TYPHOONS FORMED?

• They begin as tropical disturbances in warm ocean waters with surface temperatures of at least 26.5 degrees Celsius. These low-pressure systems are fed by energy from warm seas.
• A storm with wind speeds of 61 kilometres an hour or less is classified as a tropical depression. It becomes a tropical storm and is given a name, according to conventions determined by the World Meteorological Organization when its sustained wind speeds top 63 kilometres an hour.
• They are enormous heat engines that deliver energy on a staggering scale .they draw heat from the warm, moist ocean air and release it through condensation of water vapour in thunderstorms.
• They spin around a low-pressure centre known as the eye. Sinking air makes this 32 to 64-kilometer wide area notoriously calm. But the eye is surrounded by a circular” eye wall “that contains the storm’s strongest winds and rain.
• While several factors determine a hurricane’s strength and impact, warmer temperatures in certain locations play an important role.
• A warmer atmosphere can also furnish more water vapour for making rain, as evaporation increases and warm air holds more vapour than cold.
• Warming temperatures also slow tropical cyclones, which can be a problem if their progression over land is extended, potentially increasing storm surges, rainfall, and exposure to high winds.

• Super typhoon Hinnamnor, currently several hundred kilometres to the east of Okinawa, is expected to skirt the Japanese islands this weekend, The storm is packing sustained winds of about 150 miles (241 kilometres) per hour and has gusts around 184 mph
• Forecasts show the typhoon moving south of Okinawa by Sept. 2, then moving northward to approach the island over the weekend. After that the path is uncertain, but projections indicate the storm will continue north toward the Korean peninsula next week, suggesting it will bypass Taiwan and the coast of mainland China.

DANGERS OF TYPHOON

• It can bring destruction ashore in many different ways. When a typhoon makes landfall, it often produces a devastating storm surge –ocean water pushed ashore by wind –that can reach six meters high and move several kilometres inland.
• Storm surges and flooding are the two most dangerous aspects of typhoons
• Torrential rains cause further damage via flooding and landslides, which may occur many kilometres inland.