CHICAGO (CBS) — Chicago drivers should expect to see some sticker shock at the gas pump very soon, as prices are expected to jump by as much as 35 cents.

As CBS 2’s Kris Habermehl reports, the gas prices in Chicago are already the second highest in the nation. At the Shell station at Route 53 and I-55 in Bolingbrook Thursday morning, the price was $3.99, which matches up to most of the area.

Gas prices have been edging up slowly lately, but a major spike is coming. The price is expected to jump 10 to 35 cents by Friday night.

“I expect a majority of gas stations to have increased prices at least 10 to 35 cents per gallon by Friday evening with most stations starting to raise prices as early as Thursday morning when compared to today’s prices. Some areas in Michigan and Indiana may flirt with $4 a gallon,” said Patrick DeHaan, Senior Petroleum Analyst.

The spot price for gasoline – the price gas stations pay before taxes – rose 21 cents just Wednesday morning.

DeHaan said a series of events led to the spike, beginning with problems at three regional refineries over the weekend, including a fire in the BP Whiting, Ind., facility. He said it was further fueled Tuesday when leakage in Wisconsin forced the pipeline firm Enbridge to shut a pipeline that delivers crude from Canada to Chicago, putting further dampers on a tight market.

“While this situation will be temporary in nature, prices will remain high as long as these problems continue,” DeHaan said.

DeHaan said at $4.01 a gallon, prices are actually 7 cents a gallon less than they were at this time a year ago, but he said that difference could be wiped out overnight.