Forecasters at the National Weather Service in Great Falls put isolated snow totals near 30 inches in the Bob Marshall Wilderness for a storm that began Saturday, October 10, 2026, and runs until 6 AM MDT on Monday, October 12. That is the top of a forecast range; the surrounding Winter Storm Warning zone is calling for 10 to 20 inches. The office upgraded a second zone along the Rocky Mountain Front from an advisory to a warning on Saturday morning.
The warning that names the Bob Marshall
The 30-inch figure sits in a single line of one product. In its Winter Weather Message issued at 10:56 AM MDT on October 10, NWS Great Falls listed the Southern Rocky Mountain Front, Southern High Plains, Upper Blackfoot, MacDonald Pass and Gates of the Mountains zones under a continued warning, with 10 to 20 inches of snow, up to 7 inches in the Lincoln valley, and “isolated totals near 30 inches in the Bob Marshall Wilderness.” Gusts in that zone were forecast to reach 45 mph.
The same message, available on the NWS Great Falls winter weather product page, upgraded the East Glacier Park Region and Northern High Plains from an advisory to a warning, effective immediately. That zone carries 10 to 20 inches of heavy, wet snow, heaviest in the mountains south of U.S. Highway 2, with gusts to 50 mph. A third warning, starting 6 PM Saturday, covers Cascade County below 5,000 feet, eastern Pondera and Teton counties, the Judith Basin and the Meagher County valleys, where the forecast is 7 to 14 inches and gusts to 35 mph.
Elsewhere in the warning, 30 inches is an outlier rather than a forecast for towns or highways. The wilderness sits in the high country of the Rocky Mountain Front, where the Great Falls forecasters expect the heaviest accumulation to stack up on the mountains.
Totals across central and southwest Montana
The Great Falls message also warns for the Little Belt, Highwood, Snowy, Judith, Elkhorn and Boulder Mountains (6 to 12 inches, highest on northern slopes between 4,500 and 6,500 feet) and the Big Belt, Bridger and Castle Mountains (6 to 14 inches). Winter Weather Advisories from 6 PM Saturday cover the northern tier, with 3 to 5 inches at lower elevations and 5 to 10 in the mountains, and southwest Montana, with 2 to 5 inches in the valleys.
NWS Missoula, in a product issued at 11:42 AM MDT, posted its own Winter Storm Warning for the Butte and Blackfoot region: 3 to 9 inches, and 12 to 18 inches in the higher mountains, with gusts to 45 mph around MacDonald Pass, Homestake Pass and Georgetown Lake. Its West Glacier region sits under an advisory only, with 1 to 3 inches expected.
Aggregated coverage by Autoblog, which reported the Great Falls forecast on October 10, cited the city of Great Falls at 7 to 14 inches, up from 5 to 11 inches overnight, and carried the Bob Marshall figure as the largest jump in the forecast. That story is a secondary account; the zone totals above are from the NWS products themselves.
Timing and travel on Monday morning
Most warnings and advisories run from 6 PM Saturday through 6 AM MDT Monday, October 12, while the East Glacier Park zones were already in effect on Saturday morning. NWS Great Falls said snow on paved surfaces would accumulate mainly between evening and late morning, with grassy surfaces taking more than roads, and that travel could be very difficult, particularly over mountain passes.
Wet snow and wind carry a second hazard. The office wrote that heavy snow and gusty wind could bring down tree branches and cause isolated power outages, and advised drivers to carry a flashlight, food and water and to check road conditions by calling 511. Further updates are posted on the office’s winter weather page. The Autoblog account gave Rogers, Flesher and MacDonald Passes as the places the 10 to 20 inch range applies.
A separate point forecast for a spot 29 miles west-northwest of Augusta, at 7,067 feet along the Rocky Mountain Front, was issued at 4:26 PM MDT on October 10 under a Winter Storm Warning headline. It called for 4 to 8 inches Saturday night, 3 to 5 inches Sunday and 2 to 4 inches Sunday night, a combined 9 to 17 inches before the snow tapers off Monday, when the forecast shows less than half an inch and a 30 percent chance of snow before noon. The point sits well above the valleys, so its totals describe the mountain front rather than the city of Great Falls, where the Autoblog report quoted 7 to 14 inches.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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