California doesn’t have much chance for rain in the next five months, and its best opportunity to break the drought there may hinge on the emergence of an El Niño in the Pacific Ocean this year, U.S. forecasters said.
The entire state is suffering some form of drought, as are 38.1 percent of the contiguous 48 states, according to the U.S. Drought Monitor. As California’s traditional rainy season has just ended, there won’t be many chances for relief until October or November, said Mike Halpert, acting director of the U.S. Climate Prediction Center in College Park, Maryland.
“Given that they are pretty much entering their dry season, it’s a minuscule chance they will see any rains,” Halpert said last week during a conference call with reporters. “Looking ahead to next winter, it will be somewhat dependent on the strength of this El Niño.”
The drought in California, the largest U.S. agricultural producer, has exacerbated wild fires burning in the southern part of the state and might force some farmers to abandoned fields as lack of water makes it impossible to grow crops.
Through the first four months of 2014, California and Arizona have experienced the hottest start to any year in records going back to 1895, according to the National Climatic Data Center in Asheville, North Carolina.
While the western U.S. was warm from January through April, the East was colder, with an overall temperature in the contiguous U.S. of 0.4 degree Fahrenheit (0.7 Celsius) below normal, the coldest start since 1993.
The chance of an El Niño forming by the end of the year is about 80 percent, Halpert said while discussing the year’s start and summer outlook. However, predicting the intensity of the event is difficult.
In March, subsurface temperatures in the equatorial Pacific were the highest on record, surpassing 1997 when an intense El Niño formed. Since then, the readings have failed to keep up with the 1997 pace and researchers aren’t sure this year will match that one in power.
An El Niño can make the southern half of the U.S. wetter, while bringing dry, warmer conditions to the northern states throughout the winter.
An El Niño is defined by sea surface temperatures at least 0.5 Celsius above normal and a corresponding change in the atmosphere above the ocean. While the temperature reached that threshold last week, it hasn’t been long enough to declare an event under way, Halpert said.
If those readings hold through May or get warmer, it’s possible the U.S. will declare next month that an El Niño is taking place, he said.
In addition to the El Niño and drought outlooks, forecasters also predicted the U.S. East, West and Gulf coasts will probably have above-normal temperatures from June to August. The eastern Rocky Mountain states also may get above-average rainfall.