What is El Niño and why could it mean record temperatures?

14 hours agoShareSaveAdd as preferred on Google Mark Poynting and Esme StallardBBC News Climate & Science Indonesia was hit 2015-16 El Niño A developing natural weather pattern called El Niño could begin within weeks, according to UN scientists, bringing more extreme weather to many parts of the world. Some forecasts suggest this El Niño could end up as one of the strongest on record, which is likely to boost temperatures on a planet already made much hotter . What happens during an El Niño and why could this one be strong? Whether we get an El Niño depends on what is happening in the Pacific Ocean and the atmosphere above it. An El Niño develops when winds that typically blow east-to-west weaken or reverse. This allows warmer water to spread across the central and eastern tropical Pacific. Over the past few months, scientists have observed rising sea surface temperatures in these regions. They have also noticed a drop in atmospheric pressure over the central Pacific compared with the western Pacific. Both are classic signs that El Niño could be on its way. The UN's World Meteorological Organization (WMO) has said it is 80% certain that El Niño will begin between June and August. Once it begins, El Niño usually lasts about a year. Some scientists have warned that this El Niño could be especially strong, partly because the water beneath the surface of the Pacific is unusually warm at the moment - 6C above average in places. Deep-sea heat is often followed . When these warm 0.5C from the baseline over an extended period, conditions for El Niño are present. Warming above 2C indicates a "very strong" or so-called "super" El Niño. These events have only happened a few times since 1950. Some forecasts suggest the forthcoming El Niño could equal past peaks - or even surpass them - although this is still uncertain. The El Niño phenomenon was first observed 1600s, who nicknamed it El Niño de Navidad - Christ Child in Spanish. Prepare for El Niño, UN warns UN issues new climate warning as El Niño looms How could a strong El Niño affect the weather? A strong El Niño event would "exacerbate drought and heavy rainfall and increase the risk of heatwaves both on land and in the ocean", said WMO secretary general Celeste Saulo.