The Northeast United States and its gas-hungry population centers can expect more 90-degree days this summer than in 2014, while the drought that has plagued California for four years may expand its footprint, according to forecasters at

"I'm not expecting extreme heat, but periods of warmer-than-normal temperatures will come and go during the course of the summer," Paul Pastelok, long-range expert forecaster at, said of the Northeast's upcoming summer.

After a cooler-than-normal summer in 2014, expects temperatures in the Northeast to average above normal, with more 90-plus degree days -- as many as 10 more than last year in Philadelphia and New York City. The southern Plains and lower- to mid-Mississippi Valley, on the other hand, will see fewer extremely hot days than in recent years, the forecaster said.

"It's not as dry going into this summer season across the entire southern Plains, and I think that will have an impact on how high and how consistently we'll hit above 90 this year," Pastelok said.

The drought in California will continue to worsen this summer, even expanding "at full force into the Pacific Northwest, especially east of the Cascades," the forecaster said.

Weather Services International also expects the drought in the West to continue, but it has said the Northeast will average cooler than normal through July (see Daily GPI, April 20).

A long-awaited El Nino event -- warmer-than-average sea surface temperatures in the central Pacific Ocean near the equator -- arrived earlier this year, but unlike some of its predecessors, it is likely to remain weak and exert little influence on global weather and climate, according to the National Oceanic and Atmospheric Administration (NOAA) (see Daily GPI, March 6). The El Nino, which is expected to continue into the summer, adds to growing concerns about snowpack and water supplies for hydropower in the western United States, NOAA said.

But at least one forecaster believes it may be time for weather observers to reconsider some long-held assumptions about temperature forecasting, including the impact of El Nino events (see Daily GPI, March 25). The El Nino events of the 1990s were different than those of the past several years, according to Michael Schlacter, chief meteorologist at Weather 2000. Past El Nino's were misforecast, and the most recent El Nino has been slow to have an impact on North American weather patterns, he said.