WASHINGTON — Sizing up gasoline prices, AAA Mid-Atlantic estimates that prices at the pump this summer could rise 40 cents or more per gallon.

Crude oil prices inched above $50 a barrel last month and gasoline refineries are beginning the annual switchover to more expensive summer gas blends.

“We may be looking at $2.60, $2.65, $2.70 by Memorial Day,” said AAA Mid-Atlantic spokesman John Townsend.

Currently, the average price for regular unleaded in the D.C. area is $2.31 a gallon, up 3 cents from a week ago, and up 25 cents from this time last year.

Townsend said that after rising at the start of the summer driving season, prices could jump again around the Fourth of July.

“We may be looking at $2.80, but we don’t think gasoline prices will increase above the dreaded $3 benchmark this summer,” Townsend said.

Also likely to affect gas prices is OPEC’s April meeting of oil-producing-exporting nations. If OPEC further restricts oil supply, it could further boost prices at the pump.