When typhoon hits a country, most of the government departments and agencies including the school authorities and non-government organizations are on high alert because of the severe effects that it can cause.
The major effects of typhoon include the data on death toll, numbers of the injured victims, extent of damages on the properties caused by raging floods and communicable diseases.
Every year, the Philippine archipelago is being hit by 20 to 25 typhoons. So, it is very vital for every government and school authorities, non-government organizations and Filipino family to be prepared for these predictable but potentially destructive weather occurrences.
What is Typhoon?
The New International Webster's Pocket Thesaurus defined Typhoon as a violent tropical storm, occurring in the Western Pacific.
What is Storm?
Storm is a natural disturbance in the atmosphere. It may be violent with a strong wind that brings rain or snow and may be a gentle movement of a large mass of air that you hardly notice. Sudden changes in temperature over a local area cause some of our most violent storms.
What is the eye of the storm?
This is a circular area of very low pressure. It may vary from a few miles to about 25 miles in diameter which is calmed and with no rain. It is also roughly circular area of comparatively light winds and fair weather located at the center of a severe tropical cyclone. There is small or no depositing of moisture or ice from the atmosphere upon the surface of the earth. Sometimes, blue sky or stars can be observed in the heavenly realm. As the center of the hurricane approaches an area, the wind first blows violently in one direction. Then, there is a stillness and clear skies as the eye passes. A wind blowing in the opposite direction soon follows the calm as the other side of the low passes.
Hurricanes cause great destruction due to wind in which speed may reach more than 500 miles wide and more than a thousand miles in length. Considerable amounts of rain fall in this area. The storm itself moves very slowly at first, usually a few miles a day. Tropical storms most attain wind speeds of at least 75 miles per hour before they could mean hurricanes.
From the Holland (1993) textbook, "hurricane" and "typhoon" mean as regionally specific names for a strong "tropical cyclone".
What is Tropical Cyclone?
It is the standard term for a non-frontal synoptic scale low-pressure system over tropical or sub-tropical waters with organized convection and definite cyclonic surface wind circulation. Tropical cyclones are storms with winds which spinning round. A tropical cyclone has a diameter of hundreds of kilometers and is made of several to dozens of storms.
According to meteorologists, cyclones are "lows", and typically formed when a mass of warm moist air near the earth's surface rises. This upward movement of the warm air creates Low Pressure area filled through surrounding air moving in toward the center. This air rotates in a counterclockwise motion in the northern hemisphere. As the moist air continues to rise, it becomes cooler and finally loses its moisture as rain or snow.
A falling barometer reading usually indicates a cyclone (low) is approaching. We can generally expect cloudy weather with some precipitation, strong winds, warmer and unsettled weather conditions. "Highs" tend to follow "lows" across the United States in nearly easterly direction. A shift in the wind may indicate that a high has followed a low over a given region.
For the meteorologists, the word "cyclone" does not mean a violent storm, but just a low-pressure area. A destructive cyclone means a hurricane or typhoon.
For several years, typhoons named after women by Philippine Atmospheric Geophysical and Astronomical Services Administration (PAG-ASA), before they could enter the country's area of responsibilities. PAG-ASA based its course of action into the women's unpredicted behavior.
However, at present, typhoons are already named after a pre-determined list of both male and female names before they could reach the Philippine archipelago, following some women's organizations and lady solons prevailed on their battles against that unfair treatment towards the Filipinas.
How Tropical Cyclones are developed?
There are numerous factors to form a typhoon:
- Warmed ocean waters of at least fifty meters. Warm waters are essential to fuel the heat engine of the tropical cyclone.
- An atmosphere that quickly cools enough with height that is unstable to moist convection. It has a thunderstorm activity that allows the heat stored in the ocean waters to be discharge for the development of a tropical cyclone.
- Relatively moist layers near the mid-troposphere of 5 km. This permits the continuing development of widespread thunderstorm activity.
- It has a minimum distance of at least 500 km from the equator
- It has a pre-existing near-surface disturbance and does not developed suddenly. They need a weakly organized system with sizeable spin and low level of inflow to develop.
- Low values of vertical wind shear between the surface and the upper troposphere
