By Brendan O'Brien
March 31 (Reuters) - A spring blizzard swept through the northern U.S. Plains and upper Midwest on Monday causing treacherous driving conditions under heavy snow and strong winds that forced schools and some state offices to close.
The storm was expected to dump a foot (30 cm) of snow as winds reach 60 mph (97 kph) in parts of North Dakota, South Dakota and northwest Minnesota by the time it ends Tuesday morning, according to the National Weather Service.
"It's not a typical storm. Snow amounts are on the high end of a big storm," said Jim Kaiser, a National Weather Service meteorologist in Grand Forks, North Dakota.
Near-zero visibility and hazardous driving conditions closed Interstate 29 from Grand Forks to the Canadian border as roadway conditions deteriorated in Minnesota and South Dakota on Monday afternoon, transportation officials said.
"Blizzard conditions will make travel extremely difficult, if not impossible, throughout much of South Dakota," state Transportation Secretary Darin Bergquist said in a statement.
The storm closed public schools in Bismarck, North Dakota, and delayed or cut short the school day for several districts throughout the region, according to district websites.
Kaiser said the storm is not expected to cause flooding because much of the area has been relatively dry the last month.
"Even through much of the winter, the snow we had was dry in nature because we were so cold," Kaiser said.
Forecasters expect the same system to dump freezing rain and heavy snow in southern Minnesota and Nebraska and cause wind gusts up to 35 mph (56 kph) in the southern Plains, the weather service said. (Reporting by Brendan O'Brien; Editing by Eric Walsh)