Weather hazards are extreme weather conditions that cause death and damage to property and the environment.

Examples of weather hazards include typhoons, floods, heat waves, droughts and blizzards.

It is essential to learn about these weather hazards so that precautions can be taken to minimise the damaging effects of them.

Tropical Storms

Coastal areas in the tropics experience violent tropical storms every year.

There are different names for tropical storms in different areas. They are called typhoons in Japan, China and the Philippines, tropical cyclones in Bangladesh and Australia and hurricanes in the Atlantic.

Tropical storms bring about heavy rains and strong winds reaching a speed of 200 km per hour, sometimes accompanied by thunder and lightning.

Formation of tropical storms

Tropical storms are formed over warm oceans when the temperatures of the surface is more than 27ºC. As the air over the ocean gets heated up, it expands and rises quickly, creating a low pressure region.

As the warm moist air rise to great heights, it condenses to form clouds and then fall as rain. Meanwhile, air from the surrounding high pressure regions rushes in as spirals to replace the warm air.

The speed of this spinning air can reach 200 km per hour. Large amounts of moisture are absorbed into the spirals to form cumulonimbus clouds, which then fall as heavy rain.

The denser cold air then sinks. The eye, which is the centre of the storm, is a region of calm weather with clear skies.
As the storm moves inland, it dies off because there is a lack of warm moist air.

Effects of tropical storms

There can be serious consequences when a tropical storm hits, especially so if the area is densely populated. Lives and property are lost as the storms uproot trees, destroy crops and houses, overturn cars and damage ships.

Another effect of tropical storms is the formation of a storm surge. A storm surge refers to raising of the ocean surface into a giant wave. It can destroy coastal settlements and create floods.