DETROIT - Wind gusting more than 60 m.p.h. knocked out power to about 370,000 Michigan homes and businesses yesterday as temperatures dipped back into the 20s and 30s.

Meanwhile, flood warnings were posted throughout the Midwest as temperatures rose after a week of heavy snowfall. Forecasters said flooding was possible in areas of Wisconsin, Ohio, Iowa, Michigan and Indiana.

In Michigan, winds felled tree limbs and power lines. Parts of the state also got about 4 inches of snow.

"We've had an intensifying storm system track northeast through the state," said Mark Sekelsky, a meteorologist with the National Weather Service in Grand Rapids. "As that storm intensified, it brought the winds."

Detroit-based DTE Energy Co. said that about 230,000 customers lost power yesterday, mostly in Wayne and Oakland Counties. Crews were working, but spokesman Len Singer said it could be days before power is fully restored.

"We're still assessing," Singer said.

CMS Energy Corp. subsidiary Consumers Energy said about 140,000 of its customers lost power because of the winds. Consumers said it couldn't predict when power might be restored because the winds continued.

Strong winds also gusted across Upstate New York, reaching 75 m.p.h. in the Buffalo area and toppling power poles and trees. Nearly 16,000 customers were without power in five western and northern counties. In New York City, residents relaxed as temperatures reached the mid-60s yesterday.

Melting snow and ice caused problems in the Midwest. In southeastern Wisconsin, the National Weather Service predicted the Fox River would crest about a foot over flood stage tomorrow in the town of Wheatland.

Flooding along U.S. 31 in Holland, Mich., forced Amtrak to cancel a train from Chicago to Grand Rapids on Saturday night, and at least 300 passengers were taken to buses to complete their trips, WZZM-TV reported.

Amtrak canceled one train last night and one this morning between Chicago and Grand Rapids because of the weather, Amtrak spokeswoman Tracy Connell said.

On Saturday, a line of thunderstorms swept across a swath of the Midwest, packing gusts of 60 to 70 m.p.h. in Illinois, said weather service meteorologist Patrick Bak. The storms also produced hail, and funnel clouds were reported in Missouri.

In Springfield, Ill., winds blew away part of the roof of a school district building.