With La Niña—often blamed for the worst drought in decades—now over, it’s time to look ahead at El Niño.
According to Klaus Wolter, research associate with the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder, El Niño has already begun. El Niño, which is La Niña’s opposite, occurs when the Pacific equatorial surface waters warm up.
Wolter expects the current El Niño to be a mild one, but that does not mean all of its impacts will necessarily be mild. "In 1997 when we had a very big El Niño, everyone was betting their future commodity money on Australia having a failed wheat crop," says Wolter. "That didn’t happen." The 1997-98 El Niño, one of the worst ever, was about three times the expected strength of the current El Niño.
During El Niño events, most of eastern Australia, where the bulk of the nation’s wheat is produced, is typically much drier than normal. Sections of eastern and northern Brazil, where some commercial crop enterprises are located, and India also tend to experience widespread drought conditions, whereas Argentina, Chile, and southern Brazil are more prone to flooding.
In the United States, the southern tier of the country as well as California tend to receive much heavier winter storms than usual in El Niño years, while the Upper Great Plains and Upper Midwest tend to be warmer than usual. A warmer-than-usual winter across the Corn Belt could help rebuild soil moistures if unfrozen soils can absorb precipitation.
"It’s not like we have an El Niño so everything will be fine," says Mike Timlin, regional climatologist with the Midwestern Regional Climate Center, Champaign, Illinois. "It isn’t a cure all for the drought." He says that the second year of a multi-year La Niña is associated with drought in the middle of the United States, but saying La Niña was the cause of the drought is pretty shaky. "I would be more concerned if we were going to into another year of La Niña. At least we are not saying, ‘Oh boy! We are having a bounce-back La Niña.’ For the drought to ease, though, the high pressure ridge that has set up over the United States needs to break down."
According to the National Weather Service, the drought far from over. Drought is expected to persist or worsen across much of the United States into November. Kansas, Nebraska, Missouri, Oklahoma, West Texas, Wyoming, Colorado, Nevada, Utah, southern Iowa, western Illinois, and eastern New Mexico will all see worsening conditions, while Indiana and much of eastern Illinois will see improvement.
Elsewhere in the world, the Middle East from Iran to Afghanistan tends to be wetter than usual in an El Niño year, while impacts in China are mixed, Wolter says.
Over the centuries, some experts have blamed El Niño events like the sinking of the Titanic in 1912 and the heavy snowfall that explorers Lewis and Clark encountered while crossing of Montana and Idaho’s Bitterroot Mountains in the winter of 1804-05.
The 1997-98 El Niño was blamed for the death of 24,000 and economic damage that reached $34 billion. That El Niño caused drought in Southeast Asia, severe winter storms along the West Coast of the United States, floods in East Africa, and a mix of floods and drought in China.