Hail in Burleigh County, North Dakota

The severe thunderstorm that passed over the Harmon Lake area in Morton County moved into Burleigh County, and produced a swath of ping pong ball to tennis ball size hail as it passed to the north of the city of Bismarck. This storm caused extensive damage to roofs and vehicles.

Thunderstorms initially formed in the late afternoon in the vicinity of a surface boundary over southwest North Dakota, with additional storms then forming through the late afternoon into the evening in an environment of elevated instability and deep layer shear. Many storms became supercells, producing very large hail. Over the Bismarck-Mandan area, three separate storms produced large hail. The first storm passed through the Harmon Lake area before crossing the Missouri River and passing through the north side of Bismarck, causing extensive damage with hail up to 3 inches in diameter. As that storm moved along, a second storm formed to the south of Mandan and quickly intensified as it crossed the Missouri River and passed over developments to the south of Bismarck and over the Lincoln area. Many locations experienced two inch diameter hail with this storm, which increased to baseball size over Lincoln. One mile south of Lincoln, a hailstone was measured at 4.5 inches. These two storms caused extensive damage to structures and vehicles, resulting in millions of dollars in damage. A third severe storm then formed over Bismarck, but this storm was weaker, producing one-inch diameter hail. Additional thunderstorms then continued over central North Dakota with the main threat shifting towards strong winds late in the event. The strongest wind gust was estimated at 75 mph at McKenna Lake, near Napoleon, Logan County, where four campers were blown over.