Types of Rainfall and Formation of Typhoon

​In Brunei Darussalam

​1. Convectional Rainfall

​2. Relief or Orographic Rainfall

​1) Hot sun heats any water on the ground.

2) Water from the ground is evaporated.

3) Water vapor rises, cools, and condenses at the dew point.

4) Clouds form and rain fall.

​1) Evaporation causes warm, moist air over the sea.

2) As the air meets a hill, it is forced to rise.

3) As it rises, the air cools and condenses at the dew point.

4) Clouds form and rainfalls.

5) The air sinks over the other side of the hill. No rain falls here in the rainshadow

Typhoon​

​There are three types of tropical storms:

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​1) Atlantic ocean – Hurricanes

2) Indian ocean – Cyclones

3) Pacific ocean - Typhoons

• ​As air rises over warm ___________ ocean, huge quantity of water evaporated quickly.

• ​This evaporated air cools as it rises and condenses to form a towering thunderstorm cloud.

• ​As the cloud condenses and releases heat, which serves to power the tropical storm and draws up more and more water from the ocean.

• ​Several smaller thunderstorms may join together to form one giant spinning storm (due to the rotation of the Earth).

• ​The storm now develops an eye at its center where air descends rapidly. The outer edge of the eye is the eyewall where the most intense weather conditions (strong winds and heavy rain) are felt.

• ​When the surface winds reach an average of 125kph (75mph) the storm officially becomes a typhoon

​1) Frequency

​Temperature over the sea rises........ increase frequency of tropical storms

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​2) Intensity

​Temperature over the sea rises will give more energy fuel for evaporation ......................... storms become more intense and powerful

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​3) Distribution

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​Sea surface temperatures in the Tropics have increased by about 0.5 degrees celsius............................tropical storms affect areas outside the current hazard zone