OMAHA, NEB.—Much of the Midwest braced Wednesday for powerful winds, heavy rain and a chance of tornadoes as temperatures felt like summertime despite the official start of winter being only days away. Forecasters across the Great Plains predicted unusually warm weather, including likely record-breaking high temperatures in the mid-70s for much of Nebraska, Kansas, Iowa and parts of Missouri. The warmth comes with dangerous winds and threats of violent storms, on the heels of devastating tornadoes last weekend that cut a path through states including Arkansas, Missouri, Tennessee, Illinois and Kentucky, killing at least 88 people. The National Weather Service issued a high wind warning for an area stretching from New Mexico to upper Michigan—including Wisconsin and Illinois—with sustained winds between 25 mph and 40 mph (40 kph to 64 kph) and widespread gusts of 60–75 mph (97–121 kph). The weather service’s Storm Prediction Center said embedded gusts of up …