Today...Mostly cloudy. Occasional flurries. Highs 10°F to 16°F. Lowest wind chill readings -14°F to -24°F in the morning.

Tonight...Mostly cloudy in the evening then becoming partly cloudy. Lows -9°F to -17°F.

Wednesday...Partly cloudy in the morning then becoming mostly cloudy. Occasional flurries. Highs 12°F to 18°F. West winds around 15 mph in the afternoon. Lowest wind chill readings -27°F to -37°F in the morning.

Wednesday Night...Partly cloudy. Occasional flurries through the night. Lows -5°F to 1°F. West winds around 15 mph in the evening.

Thursday...Mostly cloudy with isolated snow showers. Highs 18°F to 24°F. Chance of snow 20 percent. Lowest wind chill readings -10°F to -20°F in the morning.

Thursday Night...Mostly cloudy in the evening then becoming partly cloudy. Isolated snow showers. Lows 4°F to 10°F. Chance of snow 20 percent.

Friday...Partly cloudy with a 20 percent chance of snow. Highs 22°F to 28°F.

Friday Night...Partly cloudy in the evening then becoming mostly cloudy. A 20 percent chance of snow. Lows 8°F to 14°F.

Saturday...Mostly cloudy. Highs 25°F to 31°F.

Saturday Night...Breezy. Mostly cloudy with a 20 percent chance of snow. Lows 16°F to 22°F.

Sunday...Breezy. Cloudy with a 50 percent chance of snow. Highs 24°F to 30°F.

Sunday Night...Mostly cloudy with a 20 percent chance of snow. Lows 11°F to 17°F.

Monday...Mostly cloudy with a 20 percent chance of snow. Highs 21°F to 27°F.

 Hazardous Weather  Gibbon Falls Forecast  Mammoth Forecast  Midway Forecast  Norris Forecast  Old Faithful Forecast 

The Gallatin National Forest Avalanche Center is issuing a Backcountry Avalanche Warning for the Bridger and northern Gallatin Ranges as well as the mountains outside Cooke City. Heavy snowfall since Saturday has been deposited on a weak snowpack. Strong winds at all elevations have loaded slopes further. The avalanche danger is rated HIGH on all slopes. Very dangerous avalanche conditions exist in these ranges. Travel in avalanche terrain is not recommended and avalanche runout zones should be avoided.

Mountain Weather

The final round of snow dropped 6-8 inches in the Bridger and northern Gallatin Ranges. Cooke City picked up 5 inches and 1-2 inches fell everywhere else. Winds blew out of the west to northwest at 25-50 mph yesterday morning before dramatically shifting to the east mid-afternoon. Following this wind shift, mountain temperatures dropped almost 20 degrees in three hours, bottoming out at minus two Fahrenheit, while winds lessened and snowfall stopped. Winds are currently blowing 20-30 mph out of the East-South-East in the Bridger Range with other mountains having light, easterly, 10 mph winds. Today will be partly cloudy with mountain temperatures reaching the high single digits with no snowfall expected.

Snowpack and Avalanche Discussion:

The Bridger and northern Gallatin Ranges, the mountains around Cooke City and the Washburn Range:

Yesterday's 6-8 inches of snow and strong winds tipped the avalanche danger scale to HIGH on all slopes which meets the criteria for a warning. A layer of facets created at the surface eight days ago is failing and fracturing from the stress of the new snow. Almost 30 inches (2.4 inches of Snow to Water Equivalent [SWE]) fell since Saturday. On Sunday, this bad snow structure showed its first signs of instability (snow profile) (photo). On Mount Blackmore in the northern Gallatin Range we discovered poor stability test scores and a natural avalanche near the summit (video). In the Bridger Range two skiers triggered two separate avalanches near Frazier Lake. One skier was caught, partially buried and broke his femur (accident report). That same day, a skier remotely triggered an avalanche outside Cooke City in Yellowstone National Park (photo). With yesterday's snowfall and blizzard winds, I'm not touching avalanche terrain today. Sunny weather after a big snowstorm is magical, but don't let the beauty cloud your judgment. We need to give the snowpack time to adjust to its new burden.

The northern Madison Range:

The northern Madison Range got the wind, but not enough snow to warrant a warning. They received about 17 inches (1.5 - 2 inches SWE) which also fell onto a weak snow surface of small, sugary facets. These buried facets will fracture and avalanche. Slopes that were wind-loaded will likely have natural activity while others will be ripe for human triggers. These mountains demand scrutiny and a cautious approach.

Today, very dangerous avalanche conditions exist on all wind-loaded slopes which have a HIGH Avalanche Danger. All other slopes have a hefty CONSIDERABLE Avalanche Danger.

The southern Madison and southern Gallatin Ranges and the Lionhead area near West Yellowstone:

Storms flowing out of the northwest have a habit of dropping piecemeal portions to the southern Madison and southern Gallatin Ranges. These areas got a 8-12 inch snack of snowfall instead of the full value meal; but when you're hungry sometimes a snack will do. These storms also buried a surface weak layer, but the new snow load isn't enough to create widespread instability. Yesterday a skier on Bacon Rind found mostly stable conditions. Skiers near Hebgen Lake and snowmobilers at Lionhead found similar results: good riding and turning on the new snow with no signs of instability. The weak layer is easy to find since it's only buried under the new snow.

For today, our primary avalanche concern is on wind-loaded slopes that have a CONSIDERABLE Avalanche Danger. All other terrain has a MODERATE Avalanche Danger.

Information provided by Doug Chabot, Mark Staples, and Eric Knoff from the Gallatin National Forest Avalanche Center.

If you have any snowpack or avalanche observations, drop them a line at mtavalanche@gmail.com or call: 406-587-6984.

For detailed Avalanche Terms utilized here, please see the Avalanche Glossary.

West Yellowstone: Beacon Park Operational

Skiing or riding near West Yellowstone? Test your beacon skills at a beacon park near the old airport where you can search for pre-placed beacons switched on/off by a control panel. Look for it by orange snow fence and signage just south of the snow cross track.

9th ANNUAL KING AND QUEEN OF THE RIDGE

The 9th Annual King and Queen of the Ridge will be held at Bridger Bowl on Saturday, February 12. ALL proceeds go to the Friends of the Avalanche Center who use the money to promote avalanche education in southwest Montana. Last winter we taught 64 classes reaching over 4,900 people. You can help raise money to continue this education in 2 ways:

1). Get pledges and hike the ridge. You don't have to do 20 laps – you can get flat pledges and hike just once! Or you can test your mettle and try and break John Yarington's record of 29 laps in 5 hours.

2). Sponsor someone. If you don't have someone to sponsor, consider sponsoring the GNFAC since we'll be hiking for dollars. Click Here for more information and registration forms.