Typhoon Information PDF

# Typhoon A lot of people did not know what about the term tropical cyclone. This is the reason why we are using the common word "typhoon" but remember that typhoon is just one category of tropical cyclones. ## Location of Typhoons The Philippine archipelago is strategically *located within the...

# Typhoon A lot of people did not know what about the term tropical cyclone. This is the reason why we are using the common word "typhoon" but remember that typhoon is just one category of tropical cyclones. ## Location of Typhoons The Philippine archipelago is strategically *located within the typhoon belt* of the Pacific, lying within the proximity of the Intertropical Convergence Zone (ITCZ) where trade winds converge, and storms commonly form within the Pacific. Other countries that lie within the ITCZ are also prone to typhoons. ## What is a Typhoon? According to the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA), about 20 tropical cyclones enter the Philippine Area of Responsibility each year. Every year the Philippines is hit by typhoons. - A typhoon or commonly named as "bagyo" is a *giant, rotating storm* that brings wind, rain, and destruction. Hurricanes and typhoons are both kinds of tropical cyclones. ## Effects of a Typhoon - The moment a *typhoon struck a certain area*, you can directly know and expect its possible damages. - During *typhoon there is a lot of rain and strong winds*. - You may have noticed also that the *winds during typhoon move in a certain direction*. They go around a central area. ## The Formation of a Typhoon - Typhoons are made over the ocean and typhoons are not made over land. - To make a Typhoon you need a lot of *warm, moist air evaporating off the ocean surface and rising rapidly*, creating the area of relatively low pressure - a weather system. ## The Characteristics of a Tropical Cyclone - The Philippines is located near the equator and is surrounded by bodies of water. This combination means the heat from the equator enables it to warm up the waters of the ocean and produce a lot of water vapor. The rising warm air will soon turn into a low-pressure area that may intensify into a tropical cyclone. - Tropical cyclone is a storm system characterized by *counter clockwise rotating air mass around a central part called eye* that has a low pressure. - The word "cyclone" comes from the Greek word, "Cyclops" - a giant with only one eye. - The center of the cyclone is called the 'eye'. - Cyclone eyes can be as small as 3km to 320km across. The average diameter of a cyclone eye is 50 kilometres (km) across. - Winds around the eye's wall are the strongest but the winds inside the eye are the weakest or lightest. It is characterized by strong winds and heavy rains. *The winds go around a central area clockwise direction*. - Thus, tropical cyclones require warm ocean waters to be able to develop. - According to scientists, the temperature of ocean water must be 26.5°C or greater. Winds collect moisture and rise, while colder air moves in below. This creates pressure, which causes the winds to move very quickly and rotates, or spins, around a center called an eye. The warmer air and moisture there is, the more intense the winds. - A typhoon forms when winds blow into areas of the ocean where the water is warm. - These winds collect moisture and rise, while *colder air moves in below.* This creates pressure, which causes the winds to move very quickly. The winds rotate, or spin, around a center called an eye as shown in the picture above with the one being encircled with black ink. The more warm air and moisture there is, the more intense the winds. While typhoons can occur any time of year, the conditions are most likely to be right for them to happen between June and November. ## Tropical Cyclone Categories - In order for a storm to be a typhoon, wind speeds have to reach at least 74 miles per hour. - Once a storm becomes a typhoon, wind speed also determines the category of the storm. - Tropical cyclone is classified into categories depending on its wind speed. - Super typhoon when the wind speed is greater than 220 kilometers per hour (kph). - Typhoon when the wind speed is less than 118 to 200 kph. - Severe tropical storm when the wind speed is 89-117 kph. - Tropical Storm when the wind speed is between 62 and 88 kph. - Tropical Depression when the wind speed is between 33 to 61 kph. ## Table Describing Wind Speed Categories To have a clear view of the different categories of typhoon the table below is being presented to you; | Categories of the Tropical Cyclone Category | Maximum Wind Speed kilometers per hour(kph) | |:---|:---| | Tropical Depression | 33-61 | | Severe Tropical Storm | 62-88 | | Typhoon | 89-117 | | Supertyphoon | Greater than 220 | ## Definition of Terms - The 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. ## Simplified Typhoon Formation A simple illustration on how typhoon is developed. 1. Typhoons start off as tropical thunderstorms. The strong winds pull in moisture from the oceans. 2. The thunderstorms convert the moisture into heat. The heat causes more air to flow to the center of the storm causing evaporation. 3. All the heat and air flow toward the eye creating the typhoon.