TYPHOON

A typhoon is a mature tropical cyclone that develops in the western part of the North Pacific Ocean between 180° and 100°E. This region is referred to as the Northwestern Pacific Basin, and is the most active tropical cyclone basin on Earth, accounting for almost one-third of the world's annual tropical cyclones. For organisational purposes, the northern Pacific Ocean is divided into three regions: the eastern (North America to 140°W), central (140°W to 180°), and western (180° to 100°E). The Regional Specialized.

Category Sustained winds
Typhoon 64–84 knots
118–156 km/h
Severe Tropical Storm 48–63 knots
89–117 km/h
Tropical Storm 34–47 knots
62–88 km/h
Tropical Depression ≤33 knots
≤61 km/h

HOW ARE TYPHOONS FORMED?

In tropical oceans, the water in the oceans' surface layer heated by the direct solar radiation. As a result, the air above the tropical oceans is characterized by high temperature and humidity, resulting in air inflation that easily leads to low density per unit volume of air. Weak wind near the equator causes the lighter air to soar and incur convection that further attracts inflow of surrounding cooler air. The intake air then warms up and soars again, creating a positive feedback cycle that eventually forms an air column with high temperature, light weight and low density. This is how the tropical depression forms.

The air flows from high pressure towards low pressure as if the water flows from high to low elevation. The surrounding air with higher pressure will flow towards where the pressure is lower, creating the "wind." As the area for direct solar radiation moves northward away from the equator in summer, the southeasterly trade wind in the Southern Hemisphere crosses the equator and penetrates into the Northern Hemisphere in the form of southwest monsoon, which has heads-on encounter with the northeasterly trade wind in the Northern Hemisphere and forces the air in this area to soar, creating more convection. Furthermore, the wind convergence resulting from the southwesterly and the northeasterly trade winds often cause air turbulence and whirlpool. These convergence effects, when continually enhanced by the convection activity.

HOW TO BE PREPARED

WHAT TO DO BEFORE A TYPHOON

• Inspect your house if necessary repair/fixing is needed. (eg. Roof, doors, windows, ceilings)
• Before typhoon strikes, you must clean up your house’s drainage system so it won’t get clogged up.
• Store an adequate supply of food and water that would last for a few days. Canned goods are ideal especially if cooking is not possible.
• Put everything in your house in an elevated position especially items that generate electricity so that water won’t penetrate into them in case floodwater rushes inside your house.
• Harvest crops that can be yielded immediately.

WHAT TO DO DURING A TYPHOON

• Stay inside the house and keep calm. Postpone any travel.
• Monitor to your local radio, television or visit Weather Philippines for storm advisories on the progress of the typhoon.
• In case of flooding, turn off the main sources of electricity to prevent electrical accidents.
• Avoid wading through flooded areas to avoid water-transmitted diseases.
• Do not operate any electrical equipment during a flood.

WHAT TO DO AFTER A TYPHOON

• Monitor to your radio, television or visit Weather Philippines for storm advisories on the progress of the typhoon.
• Check your house for damage and make necessary repairs at once. Avoid scattered debris especially tin and lumber as there may be rusty nails protruding
• Wear proper safety gear and equipment when working in hazardous areas.
• If your house was damaged, make sure that it is already safe and stable when you enter.
• Have a knowledgeable person inspect electrical connections before using electrical appliances.

Sources:
http://weather.com.ph/typhoon/preparedness, and other sites