Heavy rain and thunderstorms are forecast to sweep across the Twin Cities and southern Minnesota on the Fourth of July, potentially affecting holiday events and bringing more rain to areas with recent flooding.

The National Weather Service has issued a hazardous weather outlook for the region, warning residents to be careful when driving during the holiday. National Weather Service meteorologist Joe Calderone urged residents to check the status of Fourth of July events before heading out Thursday.

"Certainly with rainfall that could impact outdoor shows, fireworks shows and things of that nature," Calderone said.

Due to the inclement weather forecast, the Lake Minnetonka fireworks display will be moved to Wednesday night instead of Thursday night, the Excelsior-Lake Minnetonka Chamber of Commerce said in a Facebook post. The fireworks will begin at 9:50 p.m. Wednesday at Excelsior Commons park. Other Independence Day events in Excelsior will still be held Thursday.

Chances of widespread rain will begin early Thursday morning, but the majority of the storms are forecast to start in the afternoon and continue through Thursday night, with scattered thunderstorms anticipated south of Interstate 94, Calderone said. Totals will vary but several inches of rain are possible. Boating and camping in particular could be affected since electrical storms are possible, Calderone said.

Many areas of southern Minnesota have already been grappling with damage and closures caused by the wet summer. Because the flooding levels have already crested in rivers across southern Minnesota, Thursday's rainstorms are not expected to raise water levels more. But rain would probably slow the retreat of the rivers or maintain the current levels, Calderone said.

A flood warning was issued Tuesday morning for areas along the Mississippi River in southeast Minnesota and along the Minnesota River southwest of the Twin Cities. The warning remains in effect until late Sunday morning.

The rainy weather is expected to stretch into Friday morning and afternoon, and there will still be a chance of rain during the weekend. Calderone's main advice was to not disobey hazard signs if roads are closed due to rain, and to follow suggested detour routes.