Gasoline prices seen jumping at least another 10 percent
Gasoline prices, already up about 12 cents in two weeks, are expected to bubble up at least another 10 percent before peaking in the spring.
"I do suspect that March will probably deliver the largest increases," said Tom Kloza, chief oil analyst at GasBuddy. "I think they top out, and then I think they drop back."
Gasoline is averaging nearly $3.41 per gallon nationally, up 6 cents from last week, according to AAA. Kloza expects to see regular unleaded gasoline rise to $3.70 a gallon by Easter Sunday, April 20.
"The worry I have for the summer is hurricane season. We have not had a hurricane strike the U.S. since we have been an export country. We export 1.3 million barrels of diesel and probably looking at exports of gasoline that are 700,000 barrels a day," he said, adding that U.S. export refineries tend to be along the Gulf Coast.
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GasBuddy.com has been forecasting more expensive gasoline because of the start of annual refinery maintenance for the shift to summer fuels.
Other factors include higher oil prices and lower output from European refineries.
"I'm expecting that gasoline prices over the next couple of weeks are going to rise and approach $3.50 a gallon nationwide," said Andrew Lipow of Lipow Oil Associates. "The main reason is actually that crude oil prices have been rising, as well as prices of gasoline futures."
WTI crude futures are now trading above $103 a barrel, after trading under $100 for several months.
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"We're in the midst of the refinery maintenance season, as we go through March," Lipow said. "Some supplies through the East Coast are going to be impacted by local refinery outages. Some are out and combing back at the end of February."
Even with a quick jump in retail gasoline prices, the increase is likely to be below average for the annual winter-to-spring changeover.
The average increase in futures prices in the past 30 years has been 57 percent, which would be $1.40 a gallon, according to GasBuddy, though it expects a much smaller rise. Regular gas averaged $3.30 a gallon for the first six weeks of 2014, the cheapest since 2010.
Lipow predicts that prices will peak at about $3.70, and then head lower around Memorial Day, the start of the summer driving season. That's below last year's price, which was averaging $3.77 a gallon a year ago.
Kloza said the areas affected by the highest prices last year—including the Upper Midwest and Minnesota—will be well-supplied this summer. But the Northeast, California and, for a briefer time, the Southeast could be hit by higher tabs at the pump.
The refinery maintenance schedule is also affecting oil prices, and traders expect petroleum products to stay tight.
"Distillate fuels are so tight, it's supportive," said John Kilduff of Again Capital.
Supplies of those fuels, which including heating oil, are at their lowest levels in nearly two years and could be driven lower by the maintenance work.
—By CNBC's Patti Domm. Follow her on Twitter