WASHINGTON - Relief is forecast to be on the way for a weather-weary United States with the warming of the central Pacific Ocean this year that is predicted to change weather worldwide. But it won’t be for the better everywhere.
The warming, called an El Nino, is expected to lead to fewer Atlantic hurricanes and more rain next winter for drought-stricken California and Southern states, and even a milder winter for the nation’s frigid northern tier next year, meteorologists said.
While it could be good news to lessen the southwestern U.S. drought and shrink heating bills next winter in the far north, “worldwide, it can be quite a different story,” said North Carolina State University atmospheric sciences professor Ken Kunkel. “Some areas benefit. Some don’t.”
Globally, it can mean an even hotter year ahead and billions of dollars in losses forfood crops.
Arkansas meteorologists expect the appearance of an El Nino will mean a less-than-average chance for any late summer tropical-storm moisture that can break up droughts. But it also can create a wetter winter, said National Weather Service meteorologist John Lewis of North Little Rock.
The state last experienced the effects of an El Nino in 2009-10. Since then, in the summers of 2010, 2011 and 2012, Arkansas has seen three of the state’s 15 hottest summers on record. Last year, temperatures cooled and, after a moist spring, the summer was only the 90th-hottest on record, Lewis said.
“This summer will probably be in between those two extremes,” he said. “I think we were spoiled last year bythe cooler temperatures. This summer will be hotter, but nowhere near the previous three years.”
The El Nino pattern alters wind currents in the tropics, creating more shear over the Atlantic Ocean basin and resulting in fewer chances for hurricanes to form. In 2012, remnants from Hurricane Isaac, a Category 1 storm that hit the coast of Louisiana on Aug. 27, churned through Arkansas and broke a drought in most of the southern half of the state.
“There’s less of a chance for that,” Lewis said.
There’s a likely chance the state will see more moisture near the end of the year, but it may not experience the continuous rounds of snowfall the state did this winter, he said. Arctic air kept temperatures much lower this winter, making precipitation freeze more often. Lewis said temperatures in November and December should be higher.
Mike Halpert, acting director of the National Oceanic and Atmospheric Administration’s Climate Prediction Center, said the El Nino warming should develop by this summer, but that there are no guarantees. Although early signs are appearing already a few hundred feet below the ocean surface, meteorologists said an El Nino started to brew in 2012 and then shut down suddenly and unexpectedly.
The flip side of El Nino is called a La Nina, which has a general cooling effect. It has been much more frequent than El Ninos lately, with five La Ninas and two small-to-moderate El Ninos in the past nine years. The last big El Nino was 1997-1998. Neither has appeared since mid-2012. El Ninos are usually strongest from December to April.
Halpert said it is too early to say how strong this El Nino will be. The past four have been weak or moderate and those have fewer effects on weather.
Scientific studies have tied El Ninos to farming and fishing problems and to upticks in insect-born disease, such as malaria.
Commodity traders even track El Nino cycles. A study by Texas A&M University economics professor Bruce Mc-Carl determined the last big El Nino of 1997-1998 cost about $3 billion in agricultural damage.
Kevin Trenberth, a seniorscientist at the National Center for Atmospheric Research, agreed that an El Nino is brewing. Trenberth said this El Nino may even push the globe out of a decade-long slowdown in temperature increase, “so suddenly global warming kicks into a whole new level.”
Kunkel said if this El Nino is a strong one, global temperatures, probably in 2015, could “be in near record-breaking territory.”
Halpert, however, said El Ninos can be beneficial, and the one being forecast is “aperfect case.”
After years of dryness and low reservoirs, an El Nino’s wet weather would be welcome in places like California, Halpert said.
“If they get too much rain, I think they’d rather have that situation rather than another year of drought,” Halpert said. “Sometimes you have to pick your poison.” Information for this article was contributed by Seth Borenstein of The Associated Press and by Kenneth Heard of the Arkansas Democrat-Gazette.
Front Section, Pages 5 on 03/07/2014