Undated (AP) _ Much of sopping-wet Michigan was under a flash-flood watch today, the victim of another round of storms that carried torrential rains and tornadoes across the Midwest.

Friday's violent weather packed winds up to 81 mph as it injured one person and damaged school buses in Indiana, left up to 3 feet of water on streets in Wisconsin and delayed flights in Chicago.

In Montana, the rain-gorged Milk River continued to overflow its banks after forcing more than 100 people from their homes Friday. Water stood up to 5 feet deep in Harlem, where one woman drowned. The rising river also threatened to overwhelm a levee at Malta, a town of 2,400 people downstream from Harlem.

The storms rolled over southern Michigan about sunset Friday, swelling rivers as they continued a 17-day assault. Flooding this month has caused $323 million damage in 22 central Michigan counties, officials have said.

Saginaw County, hit by nearly two weeks of rain beginning Sept. 10, and the Flint area were expected to bear the brunt of the new storms expected to last through Sunday, said National Weather Service hydrologist Gary Charson.

''It's going to cause flooding problems,'' Charson said. ''The ground is still saturated from the repetitive heavy rainfall events that have befallen the state the past couple of weeks.

''The mitt of Michigan is mildewed.''

Flash-flood watches were in effect for the southern two-thirds of Michigan's Lower Peninsula, with up to 4 inches of additional rain forecast for the region.

A state of emergency was declared in Van Buren County, where more than $200,000 damage was sustained by 50 to 70 homes, officials said. More than 7 inches of rain fell in two days in the area.

The storms that began early Thursday have killed one person and injured five in South Haven Township, police said. Eight people have died in this month's Michigan floods, and one person presumed drowned is still missing.

In Elkhart, Ind., a tornado that touched down Friday afternoon overturned a school bus but injured neither of the two people aboard. One person was slightly injured when the storm felled a tree.

The weather service reported a narrow path of damage and flooding about 2 miles long in the city, and about 12,000 homes lost electricity.

Had the storms hit 10 minutes later, every child in Elkhart Central High School would have been aboard buses on their way home, said Assistant Principal Robert Minichillo. ''We were blessed,'' he said.

Most area schoolchildren were kept at school until the storms passed.

Five parked semis overturned at Elkhart's Whitehall Laboratories, where 81 mph winds peeled the roof off a warehouse.

Officials in La Crosse, Wis., declared a flood emergency because of a threat to roads along low-lying areas.

The Mississippi River at the western Wisconsin city rose to 13.5 feet, half a foot above flood stage and the highest recorded September level. The river was forecast to crest at about 13.7 feet Sunday.

The storms knocked down trees in Sheboygan in eastern Wisconsin, blocking roads and damaging buildings. The city reported 2.36 inches of rain in less than a half hour.

Streets in Cedarburg, Wis., were under as much as 3 feet of water, said Ozaukee County emergency director B.J. Wagner-Adam. High winds flipped and demolished a mobile home south of Montello, in Marquette County, said deputy sheriff Kevin Koeshall.

Northeastern Illinois got 2 inches to 3 inches of rain in three to four hours, said weather service spokesman James Hall.

Power was out to parts of Chicago and its suburbs, and some streets were flooded in the city, officials said.

At O'Hare International Airport, the weather delayed flights for about 1 1/ 2 hours, said O'Hare Police Officer Chester Anderson.

And in Naperville, Ill., lightning triggered all the burglar alarms that connect local businesses to police headquarters, said Lt. George Pradel.

''It was a little scary at first, but we've determined that there were no (burglary) incidents,'' he said.

In Ohio, thunderstorms carrying wind gusts of 40 to 50 mph brought golf ball-sized hail to Muskingum County and uprooted trees in Oberlin. A half-inch of hail fell at the Akron-Canton airport.

Strong winds tore 50 square feet of fabric from a four-story metal scaffolding set up at Cleveland's Public Square for a balloon festival today. The scaffolding was expected to be repaired in time to hold an estimated 2 million balloons, festival spokesman George Fraser said.

To the east, a line of severe thunderstorms hit central and southern New Jersey with heavy rain, high winds and lightning Friday night, knocking down trees and power lines.

Utility officials said electrical service was interrupted for about 20,000 residential customers, mainly in Monmouth and Ocean counties.