Record-breaking September snowstorm dumps 4 feet of snow on parts of Montana, USA

A record-smashing snowstorm with wet snow and strong winds hit parts of the Northern Rockies on September 28 and 29, 2019, resulting in power outages, uprooted trees, and road closures. Several parts of Montana experienced blizzard conditions and more than a foot of snow, setting new daily rainfall records. Wind gusts from 64 to 96 km/h (40 to 60 mph) were measured in Montana.

AccuWeather Senior Meteorologist Alex Sosnowski explained the cause behind the historic snowfall, saying "the combination of a storm from the Pacific Ocean, a fresh injection of cold air from northern Canada, moisture from the Gulf of Mexico and a northeast-ascending flow that squeezed extra moisture from the atmosphere produced the amazing snowfall."

The highest snowfall was recorded in Browning, Montana with a total of 120 cm (4 feet). Meanwhile, East Glacier Park received 61 cm (2 feet) of snow.

The heaviest snowstorm of all time also fell in Great Falls, Montana on September 28 with 24 cm (9.7 inches) and September 29 with 24.4 cm (9.6 inches).

It beat the daily record of 15.5 cm (6.1 inches) set in 1954. With a total of 49 cm (19.3 inches), the two-day record came second to that of April 27 to 28 in 2009, with 61.4 cm (24.2 inches), which was the city's heaviest snowfall in two days.

It usually takes until a week before Christmas for the area to have a total of 49 cm (19.3 inches) of snowfall in an average winter.

Missoula, Montana also experienced most snow in September with a total of 4.3 cm (1.7 inches) on September 9, breaking the previous record set in 1934 with 3.81 cm (1.5 inches).

In Choteau, Montana, most trees on side streets were knocked down by heavy and wet snow. Meanwhile, up to 120 cm (4 feet) drifts were reported near Fairfield, and a total of 38.1 cm (15 inches) of snow was recorded near Kiowa, Montana. 

Blizzard conditions were experienced across the northern and southern Rocky Mountain front, including at the Cut Bank, Montana, Airport where there was moderate to heavy snowfall with sustained winds of 48.3 km/h (30 mph) on September 29.

Montana Governor Steve Bullock declared a winter storm emergency on September 29. "With an unprecedented winter storm throwing our state a surprise in September, state and local governments are working closely together to protect the health and safety of Montanans," he said.

"The storm brought heavy, wet snow with accumulation amounts up to three feet in some locations. High winds have downed trees and power lines resulting in road closures, emergency travel conditions, intermittent cellular service, and power outages," the governor's office stated in a press release.

The Blackfeet Indian Reservation, Glacier County, and Pondera County issued their own local emergency alerts.

While the storm weakened early Monday, September 30, several roads are still covered in snow and can pose a threat once it melts. However, some areas remain in unreasonably cold conditions which will delay the subsiding of snow and halt the agricultural growing season.

NWS compared this snowstorm to the record one in 1934, which dropped over 30 cm (1 foot) of heavy snow in Cut Bank and Great Falls, Montana, and more than 15 cm (6 inches) in Helena. 

Featured image credit: National Park Service