(Updates with hurricane forecast in 11th paragraph.)
April 10 (Bloomberg) -- The chances are growing that a weather-altering El Nino will develop in the Pacific Ocean later this year, the U.S. Climate Prediction Center said.
The odds are now 65 percent, up from 52 percent, that the warming of the equatorial Pacific will form sometime after August, said Mike Halpert, deputy director of the center in College Park, Maryland. Earlier this week, the Australian Bureau of Meteorology gave El Nino development a 70 percent chance.
“We are becoming more bullish now,” Halpert said by telephone.
The last El Nino to form was in 2009 to 2010, and since then the Pacific has either been in its cooler state, called La Nina, or neutral.
A warmer ocean affects the atmosphere above it, changing weather patterns around the globe. El Nino can mean less rain in India, Australia and Central America in the summer; mild conditions across the northern U.S. in the winter and a cooler summer; and more rain across the South, according to the National Oceanic and Atmospheric Administration.
The stronger the El Nino, the more pronounced its impacts. Currently, the heat content in the Pacific is at its highest March value since records were first kept in 1979, the center said in its forecast analysis today.
While that may seem to indicate an El Nino is a sure thing and its impacts will be widespread, Halpert said it is too early to draw that conclusion.
The Pacific is now in a cool phase that has spanned the last few years, he said. As a result, forecasters have seen heat values close to present levels in years when El Ninos didn’t form.
Some computer forecast models are calling for that to happen again, he said.
“That’s not the likely solution but it’s something that could happen,” Halpert said.
The possibility of an El Nino figured into Colorado State University’s seasonal Atlantic Ocean hurricane forecast, released today. It predicts a below-average nine named storms. The Pacific phenomenon can create winds that tear apart tropical systems in the Atlantic.
Commodity Weather Group LLC is predicting this summer will be cooler than the past four, in part because of El Nino. The year may end up generating a population-weighted cooling degree day value of 880, compared with 910 in 2013 and 1,037 in 2011, which was the hottest summer of the current century, said Matt Rogers, Commodity Weather president.
Cooling degree days values are calculated by subtracting 65 degrees Fahrenheit (18 Celsius) from the average daily temperature. The higher the value, the more energy is likely to be used to cool homes and businesses.
While a hot summer isn’t likely this year, one where the temperatures are far below normal probably isn’t either, said David Gold, a senior scientist at Weather Decision Technologies in Norman, Oklahoma.
“If you are going for a cool summer, you really have to have a good reason,” Jon Davis, a meteorologist at San Diego- based EarthRisk Technologies, said at a seminar held by Commodity Weather in San Antonio last week.
Other events may override any El Nino affects this year, Davis said. Drought across the U.S. Southwest may persist and help generate heat that could then spread across the southern states.
It would also be premature to think an El Nino will be a boon for Midwestern agriculture, said David Streit, a co-founder of Commodity Weather. The phenomenon doesn’t guarantee plentiful rain.
“Everybody has decided it’s going to be bumper crops because we’re going into an El Nino,” Streit said in San Antonio. “The point is, El Nino is no guarantee of wetter, cooler conditions in the Midwest.”