Booming thunder awakened many residents before 4 a.m. Thursday as heavy rainfall pounded the Twin Cities metro, flooding roadways and prompting the issuance of flash flood warnings for several metro counties.

The National Weather Service warned of rainfall totals of an inch or two an hour, which could lead to flooding in ponds and streams, and affect roadways.

A flash flood warning for Hennepin County is in place until 1 p.m., while Ramsey and Dakota counties are under a flash flood warning until Friday morning.

Early this morning, standing water already was causing problems:

-Standing water blocked the right lane on Hwy. 280 at Hennepin Avenue in Minneapolis.

-Cedar Avenue was covered in water in both directions near the Mall of America.

-Traffic was slogging its way along westbound 494 at Pilot Knob Road and ahead at Portland Avenue.

Hwy. 169 in the Belle Plaine area was also under water.

By 6 a.m, the weather service based in La Crosse, Wis., was warning of 40-50 mph winds and torrential rainfall in Rochester, Minn., from 6:15 a.m. to 7 a.m.

Dakota Electric reported that 1,300 customers were without power as of 6 a.m. in the Lakeville area. "We don't [know] the cause yet, but personnel are working on it," the company's Twitter feed said.

Meanwhile, firefighters were battling a blaze at a Lakeville home near Foilage Avenue and Frazer Path, police confirmed.

The potential for flooding remains high in much of southern Minnesota through tonight.

"Much of the Minnesota River and the Mississippi River from St. Paul down toward Red Wing could reach flood stage by the weekend," said a statement issued by the weather service's Chanhassen office.

The weather service said Minnehaha Creek was rising quickly, threatening to overflow its banks in Edina, Minnetonka and south Minneapolis.

Elsewhere, flood advisories issued after 2 a.m. Thursday for Clay and Redwood counties remain active until 9 a.m.

In northeastern Minnesota, the Duluth Fire Department issued a red flag warning for Park Point beaches yesterday that continues until 10 a.m. Thursday. The warning means wind and wave conditions support deadly rip currents.

The heavy rainfall in the Upper Midwest this week has caused devastating losses and led to dramatic rescues.

On Wednesday, coaches and rowers from the University of Minnesota rescued an injured woman from the Mississippi River who'd become tangled in trees. In southeastern Wisconsin, firefighters rescued two men after their truck rolled into a flooded ditch.

Residents of Mankato were coping with flooded roads and basements on Wednesday, while bracing for more downpours on Thursday. And farmers in central Minnesota and elsewhere were counting their losses from flooded fields.

The rain is expected to continue off and on in the Twin Cities through the evening, with the possibility of damaging winds and hail. Friday promises to be mostly cloudy with the possibility of scattered showers.