Rain and snow falling in North Dakota on Oct. 3, 2012.
Credit: National Weather Service
Autumn has only just begun, but it's already snowing in Montana and North Dakota. But it turns out that it's not that weird an occurrence.
The town of Heart Butte, Mont., has already received 6 inches (15 centimeters) of snow, while other areas have recorded about 1 inch (2.5 cm), said Chris Zelzer, National Weather Service meteorologist in Great Falls, Mont. Areas throughout eastern Montana, North Dakota and western Minnesota are expected to receive an inch of snow or more today (Oct. 3) and tomorrow morning, according to the National Weather Service (NWS).
This is the earliest measurable snowfall, defined as an inch of snow or more, for most of the area. On average, the first full inch of snow doesn't fall until Nov. 11 in Fargo and Nov. 15 in Grand Forks, N.D., according to the Grand Forks Herald.
Still, snowfall in October isn't that unusual for the region. "It's always surprising when you get your first snow, but it coming this early isn't that rare at all," Zelzer told OurAmazingPlanet. Parts of Montana have received snowfall as early as mid-August in the past, he said. Grand Forks, N.D., has recorded snow in every month except July, according to the NWS.
The snow results from a cold front moving south out of Canada. The terrain rises as the air moves south, lowering air pressure and decreasing the amount of water the air can hold, which then falls out as rain and snow, Zelzer said.
After the snow falls, temperatures are expected to warm again within a few days, Zelzer said. "It's part of a pattern," he said. "We'll have a cold outbreak, and then it'll warm again, and then you'll have another cold spell."
The precipitation is welcome, as much of the area has been gripped by drought in recent months, Zelzer said.