In the dead of summer, a time when attention-getting storms are typically tropical and the atmosphere is otherwise stagnant and steamy, a cyclone straight out of the spring and fall playbook is winding up north of the U.S.-Canada border. It whipped up a wild combination of snow showers and straight-line thunderstorm winds of 90-100 mph within the same state on Monday.

The storm then produced extremely strong non-thunderstorm winds on Tuesday in the northern Plains, including gusts in excess of 70 mph in parts of two states. The National Weather Service in Billings, Montana, summed the situation up bluntly in a tweet Tuesday: “This pattern should not happen in July.”Overall, impacts from the storm will lessen by Wednesday as it pulls away, however brisk winds will continue from the Dakotas to the western Great Lakes. We’ll explain the science behind this rare display later – but first, let’s get to the show itself. MORE