MARQUETTE, Mich. — Winter is not letting go across the Upper Midwest and Great Lakes as not only snow but ice accretions are threatening to create significant headaches.Of greatest concern is a multi-day freezing rain event across parts of northern Wisconsin and Michigan over the weekend, eventually spreading into the interior Northeast.Warm air is overrunning freezing temperatures trapped at the surface, combined with a long-duration precipitation event is a classic setup for a prolonged ice event.WHAT TO KNOW ABOUT ICE STORMSAn Ice Storm Warning has been issued into Sunday for the Upper Peninsula of Michigan and northern Wisconsin, where up to a half-inch of ice accretion is expected. That includes the cities of Marquette and Sault Ste. Marie in Michigan.A half inch of ice can lead to widespread power outages, falling trees and dangerous travel. And even a quarter inch can trigger scattered power outages.”A half an inch of ice over a power line can add hundreds of pounds to that power line,” said FOX Weather Meteorologist Michael Estime. “Upwards of, you know, 200 to 300-plus pounds of weight to a power line that can bring down not just power lines, but tree limbs, and tree branches that fall onto power poles… You could be talking about widespread power outages in this region.”HOW MUCH ICE IS NEEDED TO KNOCK OUT POWER, DAMAGE TREES?Already over 25,000 people have lost power in Michigan, according to FindEnergy.US.Freezing rain will push into the inland Northeast areas later Saturday and increase on Sunday.  Ice accretions of 0.10-0.25” are likely in spots, with accretions reaching a half inch in areas such as Middlebury, Vermont and Concord, New Hampshire.Heavy snows are likely in northern Wisconsin north of the ice zone and in northern Minnesota, where colder air will keep the precipitation white.  Some areas in far northern Wisconsin and Michigan’s Upper Peninsula could see 6-10 inches of snow.Up to a few inches of snow is likely in far northern New England over the weekend.