The power shortages now crippling California will be worse than state officials predicted and could spread to the Northeast, Texas and the Pacific Northwest this summer, energy industry experts are saying.

And President Bush's long-range energy plan, expected to be formally unveiled Thursday, is unlikely to offer immediate relief for those shortages or the skyrocketing gas prices that will hit Americans even harder once the summer travel season begins Monday.

Though the Energy Department said Tuesday that gasoline prices may ease around Memorial Day as production is revved up and refinery inventories rise, others cautioned that any relief will be tenuous.

John Cook, director of the Energy Information Administration's petroleum division, said any refinery disruption or pipeline problem could cause prices to soar again. "Today, little cushion exists," he said at a House hearing.

California's problems are only going to get worse. According to a report issued Tuesday by the North American Electric Reliability Council, an industry-sponsored watchdog organization, California can expect  260 hours of rolling blackouts — an average of 20 hours a week — because of a predicted power shortfall that could be as much as 5,000 megawatts during peak demand periods.

A megawatt is enough power to serve 1,000 homes.

While most of the country will have enough electricity, the council's report also warned of potential problems in the Northeast if there is a persistent heat wave, and in the Pacific Northwest and possibly in Texas. The New York City area could have blackouts if there are transmission problems on lines into the region, the report said.

In the Pacific Northwest, there is expected to be enough power to meet summer demand despite low hydroelectric generation as a result of a severe drought. But, the report said, if the region's drought continues, there could be rolling blackouts next winter.

While Texas has plenty of electricity, it "should be closely watched" because the state is shifting into a retail competitive market in June and consolidating some grid management activities, David Cook, the reliability council's general counsel, said.

"There is no magic bullet, no single thing to be done that will solve the challenges we face" in trying to assure electricity reliability, Cook said in testimony before the Senate Energy and Natural Resources Committee.

Bush's proposed energy package will recommend building more transmission lines and power plants to address future electricity needs. The president will also propose changes in air pollution rules to improve the production and distribution of gasoline.

But the White House plan will contain no strategies for increasing supply or lowering prices this summer, according to people familiar with the plan blueprints.

The Associated Press contributed to this report