Heavy, sudden thunderstorms with wind gusts of 60 mph to 90 mph pummeled south central North Dakota from Sunday night into early Monday morning, snapping tree branches onto homes, streets and buildings, causing power outages to 4,000 Bismarck-Mandan customers and creating flash flood issues for motorists.
The storm erupted shortly before 11 p.m. and proved a sharp contrast from Sunday's earlier heat index of 100 degrees. Tree branches littered Bismarck and Mandan streets Monday. Uprooted trees destroyed mobile homes.
Janine Vining, meteorologist for the National Weather Service in Bismarck, said wind gusts peaked at 68 mph at the Bismarck airport, "but winds varied from
70 to 90 mph throughout Bismarck-Mandan." She said the storm started in northwest South Dakota on Sunday afternoon and began moving into Bismarck around 11 p.m.
Dawn Schumaier was sitting on her porch watching the storm around 11 p.m., when winds crashed a 60-foot tree on her Wildwood trailer park home in southeast Mandan. She moved moments before the tree landed in her home, including where she had just been moments before.
"I heard a cracking sound and walked out onto the street and there it went," she said Monday. "It went in two parts. It went through the window and caved in the roof." Crews cutting it down and removing it believed the poplar measured 41/2 feet wide and weighed 31/2 tons.
No one was injured. A neighbor is keeping her cat and she is staying with a friend. She doubts the trailer can be repaired to be livable again.
"I had to go into the back door to get my car keys and purse," she said. "I haven't been in the front part yet."
Two homes away, a tree smashed Ralph Kratz's vehicle and his son's vehicle parked near Kratz's trailer.
Mandan Deputy Police Chief Paul Leingang said there were flooded intersections throughout town.
"There are branches all over. We've been picking up trees since midnight," said Mandan Street Supervisor Henry Hurst. "We're starting with the major arteries and then going to the residential areas." He expects cleanup might take a week.
Mandan City Forester Barry Kiemele suspects it was due to the real wet weather.
"The branches and leaves break easier. It's all over town. I was surprised," he said.
A Mandan gazebo canopy was destroyed by falling tree limbs.
Some 4,000 customers in Bismarck-Mandan lost power almost as soon as the storm hit, said Montana-Dakota Utilities spokesman Mark Hanson. All but 500 were restored by 7 a.m. Monday, and a few hundred more were still awaiting work at 3 p.m. Monday. Most of the blackout was caused by downed power lines from fallen tree branches, Hanson said. The Mandan and Bismarck fire departments reported they had responded to several downed power lines and loss of power, but none were life-threatening.
Staff at the United Tribes Technical College reported that 50 trees on campus were broken, uprooted or had lost major limbs. Many measured a foot or more in diameter. Maintenance staff was in the process of removing them.
Precipitation also fluctuated in different parts of the cities and near them, Vining said.
While the airport recorded 0.84 inches of rain with the system, the erratic system posed flash flood issues for Bismarck-Mandan drivers who also dodged flying tree branches and debris. Keith Demke, director of Bismarck's Utility Operations, said the flooding issues weren't due to pumping.
"Debris was plugging the inlets because of all of the branches being stripped off the trees," he said.
Mills Avenue is temporarily closed due to muddy road conditions, but Riverwood Drive remains open.
"There was 11/2 feet of water accumulated at Airport Road. It made Expressway near University Drive impassable at times," Vining said.
Egg-sized hail was reported five miles south of Reeder in Adams County, according to the weather service, and 80 mph winds tore off a small deck 50 miles west of Selfridge as the storm crossed county lines and moved east. Portions of Burleigh County reported pea-sized hail. Pea-to-dime-sized hail was reported through pockets of Morton County.
Ten miles north of Bismarck, winds of 80 mph to 85 mph caused a 35-foot tree with a 14-inch diameter to break. Six miles north of Bismarck, 70-plus mph winds blew a trampoline into a home, causing damage.
Vining said the conditions were ripe for the Sunday night storm because of strong westerly overhead winds, heavy humidity, strong south surface winds below and the heat.
"It was a lot of energy. It just exploded," she said.
The forecast called for today to be dry with highs in the mid- to upper 80s. Wednesday through Sunday showed there would be some chance of thundershowers or thunderstorms.
(Reach reporter LeAnn Eckroth at 250-8264 or firstname.lastname@example.org.)