(Adds possible tornado touching down in Arkansas, Minnesota details)
By Carey Gillam
KANSAS CITY, Mo., April 10 (Reuters) - High winds and heavy snow and rain whipped through parts of the central United States on Wednesday, knocking out power for thousands of people and closing schools and businesses.
There were reports of downed trees, flipped vehicles and structural damage from a potential tornado touching down in Arkansas, as storm watchers tracked a line of severe weather stretching from Arkansas through southeastern Missouri into Illinois, Indiana and Ohio.
"It will be a long night in Arkansas for sure," said Greg Carbin, meteorologist for the National Weather Service Storm Prediction Center for Arkansas and Missouri.
To the north, Minnesota Governor Mark Dayton signed an emergency order allowing the National Guard to call up people as needed to provide for recovery and shelter in southern Minnesota where there are power outages due to an ice storm.
The National Weather service has forecast up to a foot of snow (30 cm) in an area stretching across central Minnesota. Freezing rain and ice downed power lines and trees in southwest Minnesota, emergency management officials there said.
Heavy snow in South Dakota prompted state offices to close on Wednesday, as more than 2 feet (60 cm) of snow was falling. North Dakota also saw heavy snow and Kansas City was under a flash flood warning due to heavy rainfall.
The severe conditions set in on Tuesday, grounding nearly 500 flights out of Denver International Airport and dropping hail, some tennis ball-sized, through Texas and Oklahoma.
But conditions in the Plains were tamer on Wednesday. Denver International reported clear runways and a resumption of normal flight schedules.
The heavy rain and snow should benefit areas of the Plains that have been stricken by persistent drought. Soil moisture levels have been so depleted that farmers have been fearful they may not be able to produce a crop this year. But the bout of precipitation helps, said Carbin.
"We'll take everything we can get even if it comes with a little bit of hail and wind," he said. "There are aspects of this system that are actually quite beneficial." (Reporting by Carey Gillam in Kansas City; Additional reporting by Steve Olafson in Oklahoma City; David Bailey in Minneapolis; and Suzi Parker in Little Rock, Arkansas.; Editing by Scott Malone, Richard Chang and Peter Cooney)