FARGO, N.D. — Forecasters have posted a blizzard warning for the eastern Dakotas and western Minnesota as snow, strong winds and plunging temperatures move in.

The storm is creating difficult travel conditions early Wednesday with a large number of schools canceling classes, including North Dakota State University and Minnesota State University Moorhead.

The blizzard proved too much for researchers tracking the storm in the Red River Valley between North Dakota and Minnesota. Vince Goden, a meteorologist with the National Weather Service in Grand Forks, North Dakota, told KFGO-AM the NOAA/National Weather Service Severe Storm Laboratory in Norman, Oklahoma, sent a mobile, storm-chasing Doppler radar unit to the area to help study the blizzard. But Goden said the storm moved in "a little sooner" than expected, and the radar truck got stranded in a ditch west of Grand Forks early Wednesday.

The North Dakota Department of Transportation says Interstate 29 has reopened in both directions from the Canadian border to the state line of South Dakota. That stretch of interstate, a distance of more than 250 miles (402 kilometers), had been closed because of blowing and drifting snow and areas of near zero visibility.

Meteorologists expected wind gusts to 50 mph and whiteout conditions, especially in open, rural areas.

Snow accumulations will be low, at 1 inch (2.5 centimeters) to 2 inches (5 centimeters).