When water vapour is carried by warm air that rises. As it gets higher, the air cools and the water vapour condenses to form a cloud. As water molecule collide and become heavier, the water will fall to Earth as precipitation
1. The sun's heats large areas of ocean in the summer and autumn
2. Once the temperature is 27⁰, the rising warm moist air leads to a low pressure. This eventually turns into a thunderstorm. This causes air to be sucked in from the trade winds
3. With trade winds blowing in the opposite direction and the rotation of earth involved (Coriolis effect), the thunderstorm will eventually start to spin
4. When the storm begins to spin faster than 74mph, a tropical storm (such as a hurricane) is officially born
5. With the tropical storm growing in power, more cool air sinks in the centre of the storm, creating calm, clear condition called the eye of the storm
6. When the tropical storm hit land, it loses its energy source (the warm ocean) and it begins to lose strength. Eventually it will 'blow itself out'
Normally, warm ocean currents off the coast of Australia cause moist warm air to rise and condense causing storms and rain over Australia. In an El Niño year (every 2-7 years) the cycle reverses. Cooler water off the coast of Australia reverses the wind direction leading to dry, sinking air over Australia causing hot weather and a lack of rainfall
An anticyclone (areas of high pressure) that stayed in the area in July. This blocked any low pressure systems that normally brings cooler and rainier conditions
Unusually cold sea surface temperatures (3-5oC colder) found in the eastern tropical Pacific. Impacts are the opposite of El Niño, where Australia would experience droughts during El Niño, there could be an increased risk of flooding during La Niña. Likewise, Peru could experience droughts during La Niña