HELENA — Severe thunderstorms dumped up to 4 inches of rain and golf ball-sized hailstones across Montana, likely causing already swollen rivers to hit major flood stage in eastern and central parts of the state by the end of the week.
Meteorologists said Tuesday a number of funnel clouds were spotted near Billings from a storm system that moved in Monday night. The National Weather Service received several reports of tornadoes.
The tornado reports came nearly a year after a twister ripped off the roof of the city's sports arena and damaged businesses in northeastern Billings.
The weather service said hail damage and winds up to 60 mph also were reported.
Heavy rain on the already-saturated Montana soil caused flash flooding around the Musselshell River in central Montana and the Milk River in northeastern Montana.
Meteorologist Amy Schnetzler said flash flooding covered the main streets of Glasgow, in northeastern Montana, with 4 to 5 inches of water.
The area's water table was so high that basements were flooding through ground seepage. Homeowners were unable to pump them out fast enough, Schnetzler said.
A heavy thunderstorm had settled over northeast Montana midday Tuesday, threatening to dump up to 2½ inches of rain and extending flash flood warnings into the afternoon.
To the east, record water releases from Fort Peck Dam to make room in the reservoir for the winter snowmelt prompted the evacuation of seven downstream families.
The U.S. Army Corps of Engineers ramped up its releases from Fort Peck Dam into the Missouri River on Tuesday to 50,000 cubic feet of water per second. Officials said releases could go even higher. The old release record was 35,000 cubic feet per second, set in 1975.
Releases at that volume are expected to continue through July and possibly early August, said dam project manager John Daggett.
Water from Fort Peck was projected to hit the Wolf Point area in 24 hours and then Poplar and Culbertson a short time later.
At least 12 homes — and possibly as many as 36 — were considered in danger of flooding.
Roosevelt County spokeswoman Darla Shumway said the evacuated families along the Missouri River near Poplar were asked to leave after the road into their neighborhood washed out.
"It's going to get ugly, I'm afraid," Shumway said. "The water and rain is here, and it's not going to help the situation. Not only is the river running fast and higher, the banks are all saturated and some of them are starting to slough off into the river."
The high Missouri River levels also caused Poplar's sewer system to fail. Local officials said the town has rerouted sewage into a lagoon.
Around the state, dozens of counties, towns and cities were under flood watch or warning. River levels are fast approaching major flood stage in many areas as rain and melting snowpack accumulate in small waterways and empty into the rivers. Large amounts of snowpack still remain in mountain ranges. It is expected to melt and raise water levels through July.
In Western Montana, areas of the Clark Fork River above Missoula are expected to approach major flood stage in the next few days.
Officials issued an evacuation advisory for six homes in East Helena because of encroaching flood waters, emergency official Brian LaMoure said. Four families have left and two decided to stay.
A dirt berm gave way south of the town but the released water did not threaten homes LaMoure said.
Tampico on the Milk River already was at flood stage and is expect to rise to nearly 28 feet by Saturday, 4 feet above flood level. The Musselshell River by Roundup is expected to rise to 2 feet above flood stage by Friday, after swamping the town with several feet of water last month.
Red Cross officials said they were in the process of assisting towns in Blaine County after flood waters washed out roads and created mold problems in homes.
All the water from east of the Continental Divide is channeling downriver and flooding cities along the Missouri in the Dakotas and Iowa. Earthen levees have been erected around many cities to hold back the water including the South Dakota capital city of Pierre.
The Missouri River near Williston, N.D., already was at major flood stage and projected to reach 28 feet, 6 feet above flood stage by Saturday.