Geography in the News: Rare ‘triple dip’ La Niña declared

The Australian Bureau of Meteorology (BOM) has announced that the weather phenomenon La Niña has formed for the third consecutive year in the Pacific. This is only the third time since records began that there have been three consecutive La Niña events.

What is La Niña?

La Niña is a naturally occurring event, which results in the large scale cooling of ocean surface temperature. It brings with it changing global weather patterns, particularly above average rainfall to parts of Australia, increasing the risk of widespread flooding.

The La Niña weather pattern is one of the three phases of the El Niño Southern Oscillation (ENSO) - the sea surface temperature and direction of wind in the Pacific, which switches between the warm phase called El Niño, the cooler La Niña and a neutral phase. Cycling through these phases generally takes around three to seven years but this is now the third year in a row where Australia has stayed in the cooler La Niña phase - known as a 'triple dip' (previously experienced in 1973-75 and 1998-2001).

How will it affect weather around the globe?

La Niña may bring an increase in tropical cyclone activity in the Atlantic and drier conditions in East Africa - East Africa is already suffering its fourth season of failed rainfall, causing one of the worst droughts in decades, with people across Ethiopia, Kenya and Somalia at risk of sever hunger.

How will it affect weather in the UK?

The Met Office suggests that La Niña encourages high pressure to develop in the Atlantic in late autumn and early winter, which stops mild prevailing wind from the south-west, leading to colder winters, and later on in the winter we could experience an increase in storms and heavy rainfall as it drives the jet stream further north

Read the full article here and watch the excellent video that explains simply what La Niña is - a great clip for GCSE students! https://www.bbc.co.uk/weather/...