Rest Of Today / New Years Day...Mostly cloudy with a 20 percent chance of snow. Highs 21°F to 27°F. Lowest wind chill readings -11°F to -21°F late in the morning.

Tonight / New Years Night...Partly cloudy in the evening then clearing. Lows 3°F to 11°F.

Monday...Breezy. Not as cold. Mostly sunny. Highs 31°F to 37°F. South winds 15 to 20 mph in the late morning and afternoon.

Monday Night...Breezy. Mostly clear. Lows °F9 to 15°F. Southwest winds 15 to 20 mph.

Tuesday...Mostly sunny in the morning then becoming partly cloudy. Highs 27°F to 33°F.

Tuesday Night...Mostly clear in the evening then becoming partly cloudy. Lows 12°F to 18°F.

Wednesday...Partly cloudy. Highs 30°F to 36°F.

Wednesday Night...Partly cloudy. Lows 13°F to 19°F.

Thursday...Partly cloudy. Highs 30°F to 36°F.

Thursday Night...Mostly cloudy with a 40 percent chance of snow. Lows 7°F to 13°F.

Friday...Mostly cloudy with a 40 percent chance of snow. Highs 22°F to 28°F.

Friday Night...Colder. Partly cloudy with a 20 percent chance of snow. Lows 0°F to 8°F.

Saturday...Partly cloudy with a 20 percent chance of snow. Highs 20°F to 26°F.

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

AVALANCHE WARNING

The Gallatin National Forest Avalanche Center is continuing a Backcountry Avalanche Warning for the entire advisory area including the Bridger, Gallatin and Madison Ranges, the Lionhead area near West Yellowstone and the mountains around Cooke City. Heavy snowfall and high winds in the last 48 hours created large loads which fell onto an extremely weak snowpack and are causing widespread avalanches. Today the Avalanche Danger is HIGH on all slopes. Areas of unstable snow exist. Human triggered avalanches are very likely. Avalanche terrain, including avalanche runout zones, should be avoided.

* AVALANCHE FATALITY *

I am saddened to report that a snowmobiler was killed in an avalanche yesterday outside Cooke City. The snowmobiler triggered and was buried on a northeast facing slope in Fisher Creek which broke one to four feet deep and 300-400 feet wide. He was dug up within 10-12 minutes, but did not survive. Eric and his partner witnessed the avalanche and assisted in the rescue. All of us at the Avalanche Center send our deepest sympathies to family and friends. Additionally, last night Eric informed me that a cross country skier was caught and buried south of Cooke City. More details are forthcoming on both these incidents.

Mountain Weather

Yesterday was a beautiful sunny day, and so will today. Without any new snowfall, mountain temperatures hovered in the single digits Fahrenheit as winds blew out of the west to southwest at 20-30 mph with gusts of 40-60 mph seen early yesterday morning. Today, westerly winds at 15-20 mph will continue as temperatures climb into the low twenties Fahrenheit. No new snow is expected for the next several days.

Snowpack and Avalanche Discussion:

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

There are times when the avalanche danger is difficult to assess, and other times when it is easy. Today it's easy because we are surrounded by signs of instability. Extensive natural and human triggered slides were seen in all ranges yesterday. Recent wind-loading will only exacerbate the instability. Backcountry travelers will be able to trigger large avalanches from flat terrain as fractures propagate far and wide. We have very dangerous avalanche conditions, and slopes as well as runout zones should be avoided. In the last 24 hours:

1. A snowmobiler avalanche fatality occurred outside Cooke City.
2. Mark and I were able to remotely trigger avalanches up to 800 feet away near Hebgen Lake in the southern Madison Range.
3. Road cuts along Highway 191 avalanched; a low elevation warning of widespread instability.
4. Both the Yellowstone Club and Big Sky Ski Patrols triggered many large slides during avalanche control. Dozens of avalanches broke at the ground, some for their second time after reloading.
5. A snowmobile guide was in awe at extensive natural avalanche activity in the Teepee Creek area. Nearby another snowmobiler saw many slides on different aspects in Carrot Basin.
6. The bowl to the south of Saddle Peak in the Bridger Range slid naturally.

Nine photos from yesterday document these instabilities.

Most avalanches are breaking on a thick layer of loose facets (depth hoar) near the ground. These grains weakened over the past month and could not support the new snow. Although natural avalanche activity will likely subside today, it still remains very likely you can trigger an avalanche. There are slopes, most notably in the northern Gallatin Range, where you could find safer conditions. But we are including this area in our Avalanche Warning because of highly unstable snows on Mount Ellis, up Little Bear Canyon and likely other spots too.

For today, the Avalanche Danger is rated HIGH. Travel in avalanche terrain is not recommended. Wind-loaded slopes should be avoided at all costs. Winds may reload slopes that already avalanched and they may slide again; a dangerous attribute to thick layers of depth hoar.

STORM TOTALS

Precipitation totals (SWE) on Saturday morning were:

• Cooke City – 4 inches of water (~ 4 feet of snow)
• West Yellowstone – 2 inches of water (~ 2 feet of snow)
• Taylor Fork – 1.9 inches of water (~ 19 inches of snow)
• Hyalite – 1.4 inches of water (~ 14 inches of snow)
• The Bridger Range – 1.5 inches of water (~ 15 inches of snow)
• Big Sky - 1.6 inches of water (~ 16 inches of snow)

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.

EVENTS, EDUCATION, 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.