The National Weather Service said on Tuesday afternoon that the storms that rocked areas of northeast Montana on Monday evening included at least one tornado and one macroburst.
The NWS said in a Facebook post: "We still need to review aerial photos and radar data, but there was a Tornado on the south end of Plentywood, damage path is not very long though. Initial estimate is an EF-1 rating."
EF-1 is reference to the Enhanced Fujita scale that is used to classify tornadoes; an EF-1 is the lowest level of tornado.
The NWS says that their preliminary investigation indicates a macroburst hit the Plentywood Airport with speeds of more than 110 miles per hour; eight hangers were destroyed, and at least six others sustained moderate-major damage. Ten small general aviation aircraft were damaged or destroyed.
The NWS defines a microburst as: "A convective downdraft with an affected outflow area of at least 2½ miles wide and peak winds lasting between 5 and 20 minutes. Intense macrobursts may cause tornado-force damage of up to F3 intensity."
Damage in the area includes trees snapped and uprooted, roofs torn off, and shingles/tar paper torn off of buildings and homes.
Fortunately, there were no serious injuries in the area attributed to the storms.