12:45 p.m.: A heavy storm that battered Billings with 1.31 inches of rain in just 45 minutes and wind gusts topping out at 73 mph on Saturday also cut power to thousands of people across town, some of whom remained in the dark on Sunday.
Claudia Rapkoch, NorthWestern Energy spokeswoman, said the storm caused power outages for more than 5,000 customers in the area, from the West End to the Heights to Lockwood.
On Sunday morning, crews were still working to restore power to about 1,000 customers who were affected by the smaller outages.
"We got the bigger outages repaired overnight but now they’re working through those smaller ones," Rapkoch said. "Largest single we're working on now was in Lockwood where some poles went down. They're without power and our crews are out there but they're fighting with mud (from the storm)."
Rapkoch said NorthWestern has called in crews to help from the surrounding area, including contract crews.
"We've got everybody on it," she said.
A severe thunderstorm struck Billings just before 9 p.m. packing hail, frequent thunder and lightning and wind gusts of up to 73 mph.
Aaron Gilstad, a meteorologist with the Billings office of the National Weather Service said no tornadic activity had been spotted, although the high winds may have led people to think otherwise.
At 9:10 p.m., the National Weather Service also issued a flash flood warning for the Billings area because of the torrential rains that accompanied the storm. Low-lying areas of the city were flooded by the storm, according to Duane Winslow, director of Disaster and Emergency Services for Yellowstone County.
Rain totaled 1.28 inches at the airport, Gilstad said. Half-dollar-sized hail was reported off to the west of the city, he said.
"We'd been watching the storm for several hours and had a significant weather advisory on it," Gilstad said. "It really just took off here just west of town."
A large rock blocked Zimmerman Trail, and officers closed the road at the top and the bottom. Highway 3, west of Zimmerman Trail, had drifts of hail alongside the road.
The rain that washed off the Rimrocks pushed debris, including mud and rocks, onto North 27th Street near Montana State University Billings. Police were on scene and most of the road was closed to traffic.
High water at the corner of First Avenue North and Main Street caused multiple cars to stall on the road. At one point, a tree and a boat reportedly blocked Fourth Avenue North at its intersection with Main Street.
Firefighters were dispatched to power lines that were downed during the storm both in Billings and Lockwood. Tree limbs also were strewn around town.
Power outages were reported throughout Billings, said Claudia Rapkoch, spokeswoman for NorthWestern Energy.
"We have multiple outages in multiple locations all over town," Rapkoch said. "It's widespread."
Crews were sent to those spots, she said.
All of the underpasses in the downtown area were closed due to flooding, according to the Yellowstone County Sheriff's Office.
The Billings Mustangs were playing against the Missoula Osprey at Dehler Park on Saturday night. Just minutes before the storm hit, the game's announcer advised everyone to leave the baseball field and head for their vehicles.
One spectator said he got to his car just as the torrential rains started falling.
Gilstad called the weather pattern that spawned the storm unusual for this time of year.
"The amount of moisture is very unseasonable, as well," he said. "When you get that much water in the air for the storm to work with, it really intensifies quickly."
Normally, average high temperatures for this time of year are in the upper 70s, Gilstand said. That's compared with several recent days near or above 90 degrees. Nighttime temperatures also have been warmer than normal, in the 60s or 70s compared with the usual low 50s.
"Tonight will be a different story because we cooled off quickly with the storm," Gilstad said.
Billings and the surrounding area could see additional showers and thunderstorms on Sunday, with the possibility of stronger storms in the afternoon.