Today...Breezy. Cloudy with a 50 percent chance of snow. Southwest winds 15 to 20 mph. Highs 16°F to 22°F.

Tonight...Partly cloudy. Southwest winds around 15 mph early in the evening. Lows -3°F to 3°F.

Monday...Not as cold. Mostly cloudy. Slight chance of snow in the morning...then chance of snow in the afternoon. Chance of snow 40 percent. Highs 24°F to 30°F. Lowest wind chill readings -10°F to -20°F in the morning.

Monday Night...Cloudy. Snow likely in the evening...then chance of snow after midnight. Snow accumulation of 2 to 4 inches. Chance of snow 70 percent. Lows 7°F to 13°F.

Tuesday...Breezy. Cloudy with a 50 percent chance of snow. West winds 15 to 20 mph in the afternoon. Highs 19°F to 25°F.

Tuesday Night...Partly cloudy with a 20 percent chance of snow. Lows 4°F to 10°F.

Wednesday...Breezy. Mostly cloudy with a 50 percent chance of snow. Highs 23°F to 29°F.

Wednesday Night...Mostly cloudy with a 50 percent chance of snow. Lows 5°F to 11°F.

Thursday...Mostly cloudy with a 50 percent chance of snow. Highs 17°F to 23°F.

Thursday Night...Mostly cloudy in the evening then becoming partly cloudy. A 40 percent chance of snow. Lows 2°F to 8°F.

Friday...Partly cloudy in the morning then becoming mostly cloudy. A 40 percent chance of snow. Highs 19°F to 25°F.

Friday Night...Mostly cloudy in the evening then becoming partly cloudy. A 40 percent chance of snow. Lows 5°F to 11°F.

Saturday...Mostly cloudy with a 20 percent chance of snow. Highs 24°F to 30°F.

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

AVALANCHE WARNING
ISSUED ON FEBRUARY 26 2012 AT 5:00 am

The Gallatin National Forest Avalanche Center is issuing a Backcountry Avalanche Warning for the Bridger Range, southern Madison and southern Gallatin Ranges, the Lionhead area near West Yellowstone and mountains around Cooke City. Heavy snowfall, high winds and an extremely weak snowpack are causing unstable conditions. Today the Avalanche Danger is HIGH on all slopes. Natural and human triggered avalanches are likely. Avalanche terrain including avalanche runout zones should be avoided.

You are urged to contact the Gallatin National Forest Avalanche Advisory for more detailed information.

Website: www.mtavalanche.com/advisory

Avalanche Hotline: 406-587-6981

Mountain Weather

Over the past 24 hours the Bridger Range and mountains near west Yellowstone picked up 8 inches of new snow, 5 to 7 inches fell elsewhere. Winds blew 30-40 mph out of West-northwest during the storm, but have decreased to 20-30 mph out of the West-northwest. The exception is the Bridger Range where ridgetop winds are still blowing 30-40 mph. Mountain temperatures are ranging between 5-10 degrees Fahrenheit under cloudy skies. Today, temperatures will warm into the mid to high teens Fahrenheit and winds will gradually decrease to 15-25 mph out of the west. Lingering snow showers could produce 1 to 2 inches of new snow by this afternoon, but conditions will dry out by this evening.

Snowpack and Avalanche Discussion:

The Bridger Range, the southern Madison and southern Gallatin Ranges, the Lionhead area near West Yellowstone and the mountains around Cooke City:

Yesterday, 6 to 8 inches of snow fell in under eight hours, applying a rapid load to a weak and fragile snowpack. This new load will likely push the snowpack past its breaking point, producing widespread natural activity. If slopes are failing naturally, there is little chance they will support the weight of a skier or rider.

Prior to this latest storm, the snowpack was already displaying its ability to produce large natural and human triggered avalanches. On Friday, Mark and his partner observed extensive natural activity near Fairy Lake in the northern Bridger Range. On the same day a skier triggered and was caught in a potentially deadly slide on Saddle Peak. A skier also triggered a large and dangerous slide in Wolverine Bowl north of Bridger Bowl ski area.

Farther south, natural and human triggered avalanches have been reported in the mountains around Cooke City. This past Wednesday a snowmobiler was killed by an avalanche on the road leading to Daisy Pass. Yesterday, in the mountains around West Yellowstone, skiers experienced widespread cracking and collapsing, obvious signs of instability.

All these clues are sending a very clear message - THE SNOWPACK IS HIGHLY UNSTABLE! Staying off any steep slope, this includes lower angle slopes connected to steeper slopes is highly recommended. It's important to remember that even small slopes such as road cuts can produce deadly avalanches.

Today, if you travel in avalanche terrain you will likely find avalanches. For this reason the Avalanche Danger is rated HIGH on all slopes.

The northern Gallatin and northern Madison Ranges:

Although the northern Madison and northern Gallatin Ranges have slipped just under the avalanche warning criteria, they still have dangerous avalanche conditions. Yesterday, six inches of snow fell in a short period of time, applying additional stress to an already struggling snowpack. In addition to the new snow, winds blew 30-40 mph out of the west/northwest during the storm, heavily loading slopes on the east half of the compass. Today, wind loaded slopes will be the most likely to produce natural and human triggered avalanches, however, slopes steeper than 35 degrees will also be prone to avalanche activity.

Many avalanches will fracture on a layer of weak, near surface facets buried 1 to 2 feet deep. This layer exists on all aspects and in all areas. However, a few low elevation areas do not have it, mainly in the northern Gallatin Range. When avalanches break on this layer, they can easily step down to facets near the ground. This scenario occurred over the past few days at both Big Sky and Moonlight Basin ski areas during control work. Also, a skier near Big Sky observed 6 natural avalanches and remotely triggered a slide from thirty feet away on Friday.

Today, staying safe in the backcountry will depend entirely on decision making. Slopes full of untracked powder will have a powerful allure, but the avalanche dragon will be lurking. Make sure terrain is assessed carefully and always stay in visual and voice contact with your partner.

Today, very dangerous avalanche conditions exist on all wind load slopes and slopes steeper than 35 degrees which have a HIGH Avalanche Danger. Less steep, non wind loaded slopes have a CONSIDERABLE Avalanche Danger.

* * ADDITIONAL INFORMATION * *

The accident reports for the avalanche fatality near Cooke City and the slide on Saddle Peak are now available. See links below.

http://www.mtavalanche.com/sites/default/files/Saddle%20Peak%20Accident_Public.pdf

http://www.mtavalanche.com/sites/default/files/Daisy%20Pass%20Avalanche%20Public.pdf

Also, another avalanche fatality occurred yesterday near Marias Pass outside of Glacier National Park. This makes the third avalanche fatality to hit Montana in the past six days and raises the total number of avalanche fatalities in the United States to 20.

For Photos, Videos and More Detailed Information related to this report, Please Visit the Gallatin National Forest Avalanche Center.

The next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations, drop us a line at mtavalanche@gmail.com or call us at: 406-587-6984.

~ EVENT ~

31st Annual Pinhead Classic

Come to Bridger Bowl on Saturday, March 17th (Saint Patrick's Day) with telemark skis, AT skis, alpine skis, snowboards, split boards, or even snow blades. The theme is Snowpocalypse based on the wildly popular Mayan 2012 apocalypse. $30 gets you into the races, a pint glass, t-shirt, a good time, a raffle ticket, and food by Cafe Fresco. Pre-register at Mystery Ranch or Grizzly Ridge: March 11-16. Visit http://pinheadclassic.com/ or the Pinhead Facebook Page for more info.

Beacon Parks

The Friends of the Avalanche Center installed a Beacon Training Park outside West Yellowstone. It's located south of town on the main snowmobile trail. Stop by and do a quick practice before heading off into the mountains!

EDUCATION, EVENTS, PHOTOS, SNOWPITS, and VIDEOS

1. We've recently uploaded more photos and snowpits to our web site, more than what are linked in the advisory.

2. We're creating a series of "How To…" stability test videos. So far we've got clips on performing a CT and ECT. There are located under Stability Tests on the Resources page.

3. Check out all our education programs, Click Here.

Information provided by Doug Chabot, Mark Staples, and Eric Knoff from the Gallatin National Forest Avalanche Center. For Events and Education, or Photos and Videos, please visit the Avalanche Centers Website!

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.