Here’s What to Know About El Nino and the Weather

Here’s what can happen when the surface of the equatorial Pacific gets just a little warmer: Thousands of people die as the weather changes from India to Florida. Some economies lose billions of dollars; others enjoy respite from weather-related losses. Prices of commodities such as coffee and cocoa jolt skyward. Then when the waters cool, patterns shift, with areas previously spared often experiencing calamitous hurricanes, floods or drought, and others getting a break from such buffeting forces. The whole cycle is known as El Niño-Southern Oscillation. It is made up of El Niño, the Pacific’s warm phase; La Niña, the cold side; and a neutral phase in between. The whole thing kicked off again in June and is expected to peak some time around December or January.

An El Niño usually means heavy rain along the Pacific coast of the Americas, from California to Chile and across to Argentina. That could be good news for Argentina, where a record drought has worsened the country’s economic troubles. On the other hand, the last big El Niño in 2015-16 brought deadly floods to the US Midwest. The phenomenon can unleash wind shear across the Caribbean and Gulf of Mexico that can tear apart hurricanes and tropical storms, though there are few other effects to North America expected over the summer months. El Niño typically produces dry weather in Australia, Indonesia, the Philippines and northern Brazil. The last time, it reduced rainfall in the Indian monsoon, parching farmlands, and curbed production of cocoa in Ivory Coast, rice in Thailand and coffee in Indonesia. There were wildfires in Australia and South Africa.