Michigan gas prices are expected to pass $4 a gallon by this time next week.

Officials from AAA have said that Tropical Storm Issac, which is currently ripping across the Gulf of Mexico, will shut down offshore oil rigs.

The National Hurricane Center has predicted that the tropical storm will become a hurricane on Tuesday with 74 to 95 mph winds. It is expected to hit from an area southwest of New Orleans to the edge of Florida's panhandle.

The cheapest unleaded gas available in Macomb Township as of Monday afternoon is $3.89 per gallon, at 7-Eleven on N. Gratiot Avenue and Hall Road, which means gas will likely pass $4 during the Labor Day weekend.

Tropical Storm Isaac targeted a broad swath of the Gulf Coast on Monday, bearing down just ahead of the seventh anniversary of Hurricane Katrina.

The potential for a landfall as a Category 1 hurricane as soon as Tuesday prompted evacuations along a wide area of the Gulf Coast and sent people out to stock up on staples.