* Storms started in mountains, spread to plains
* Strong winds, hail, tornadoes added to damage toll
* More severe weather could slow power recovery efforts
By Eric M. Johnson
June 22 (Reuters) - One woman is dead and more than 200,000 homes and businesses are without power in the upper Midwest on Saturday after severe thunderstorms struck parts of the Dakotas, Minnesota, and Wisconsin with damaging winds, lightning and baseball-sized hail.
The storms developed in the Dakotas on Friday and powered through Minnesota into Wisconsin, producing wind gusts up to 85 mph (137 kph) and large hailstones, some in excess of 4 inches (10 cm) in diameter, as well as short-lived tornadoes, said Brynn Kerr, a meteorologist with the National Weather Service's Storm Prediction Center in Norman, Oklahoma.
A 63-year-old woman sheltering in a bathtub died when powerful winds tossed around her trailer in South Dakota on Friday afternoon, said Hamlin County Sheriff Chad Schlotterbeck.
Some 200,000 customers were still without power in Minnesota on Saturday, mainly in the Minneapolis area, and another 1,000 were without power across the border in Wisconsin, said Tom Hoen, a spokesman for Xcel Energy Inc, which serves the area.
"It was very intense ... we saw a lot of damage throughout the metro area," Hoen said, adding that branches propelled by wind gusts tore down power lines and easily uprooted trees from the water-logged earth.
"Unfortunately, because of the massive scale of the damage, we will have customers without service going into Tuesday," Hoen said, adding that a chance of weaker storms returning to the area overnight could scuttle repair efforts.
The outages affected 492,000 customers since the storm formed, Hoen said. Other utilities reported scattered outages in Minnesota and Wisconsin.
The National Weather Service expects storms building in the mountains of Wyoming and northern Colorado to push into the adjacent high plains of those states and western portions of the Dakotas and Nebraska during the late afternoon, Kerr said.
The strongest pockets are likely to hit the north-central high plains in Nebraska late Saturday afternoon and evening with driving rain and hail the size of baseballs, Kerr said.