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UNDERSTANDING TYPHOONSUnit 2MODULE 2

Overview:

Every year the Philippines is hit by typhoons. No part of the country is spared. All provinces have been visited by a typhoon at one time or another. In recent years, the Philippines had been overwhelmed by powerful tropical cyclonesWho could forget the terrible flood brought by Tropical Storm Ondoy in 2009? Or the people swept out to sea during Tropical Storm Sendong in 2011? Or the poor community of New Bataan buried in mud spawned by Typhoon Pablo in 2012?According to the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA), about 20 tropical cyclones enter the Philippine Area of Responsibility each year. We have to be knowledgeable about tropical cyclones if we want to prevent the loss of more lives.WHAT IS PAGASA?

is a Philippine national institution dedicated to provide flood and typhoon warnings, public weather forecasts and advisories, meteorological, astronomical, climatological, and other specialized information and services primarily for the protection of life and property and in support of economic, productivity and sustainable development. The Philippine Atmospheric, Geophysical and Astronomical Services Administration (Filipino: Pangasiwaan ng Palingkurang Atmosperiko, Heopisikal at Astronomiko ng Pilipinas, abbreviated as PAGASA, which means "hope" in the Tagalog word pag-asa) What is a Typhoon?We all know what a typhoon is. Or more accurately, we know what to expect when a typhoon comes. We get a lot of rain and strong winds. Now, you may not have noticed it but the winds in a typhoon move in a certain direction. They go around a central area.The English word typhoon could have originated from Persian tfn (storm), (which is pronounced "tufoon" in the Bandari dialect of Persian, spoken on the shores of the Persian Gulf from the verb tfdan (Persian: / means "to roar", "to blow furiously" .A typhoon is a mature tropical cyclone that develops in the northwestern part of the Pacific Ocean between 180 and 100E. This region is referred to as the northwest Pacific basin.

It is a violent tropical cyclone, in meteorological term, which is a low pressure system occurring in tropical oceans. The winds above the ground circulate around the center counterclockwise for a typhoon occurring in the northern hemisphere and clockwise for that occurring in the southern hemisphere.

Tropical depression, tropical storm, typhoon, and supertyphoon are categories of tropical cyclones (Table 1). In simple terms, a tropical cyclone is a system of thunderstorms that are moving around a center. As the winds intensify or weaken, the category is upgraded or downgraded accordingly. As the winds intensify or weaken, the category is upgraded or downgraded accordingly. CategoryMaximum Wind Speedkilometers per hour (kph)Tropical Depression64Tropical Storm118Typhoon200Supertyphoongreater than 200Table 1. Tropical Cyclone CategoriesThe term typhoon is used only in the northwestern part of the Pacific Ocean. In the northeastern part of the Pacific Ocean and in the northern part of the Atlantic Ocean, the equivalent term is hurricane. Thus, a hurricane on one side of the Pacific Ocean will be called a typhoon if it crosses into the other side.

In the Philippines, we use the same word for all categories of tropical cyclones. We call it bagyo whether it is a tropical depression, a tropical storm or a typhoon.ANSWER THE QUESTIONWhy is the Philippines prone to typhoons?What conditions favor the formation of typhoons?

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