Good Morning. This is Eric Knoff with an early season avalanche information bulletin issued on Wednesday, November 24 at 7:30 a.m. This Bulletin is sponsored by Northern Lights Trading Company in partnership with the Friends of the Avalanche Center. We will be shifting to daily advisories starting on Friday. Please remember that uphill traffic is not allowed at Big Sky or Moonlight Basin Ski Areas. Bridger Bowl is not open and has backcountry snow conditions
Burrrr! The coldest temperatures of the season have moved into southwest Montana turning off all precipitation. Not to worry though – this latest storm delivered over two feet of snow to the mountains around West Yellowstone, 15-18 inches to the mountains around Cooke City and 6-8 inches to the northern Gallatin and Madison Ranges. The Bridgers received a total of 2-4 inches. The latest storm is being pushed out by an arctic blast that is descending from Canada.
Currently mountain temperatures are sitting between ten and twenty below zero and winds are blowing out of the W-NW at 15-20 mph with gusts up to 30 mph. Mountain temperatures will struggle to climb above zero today and winds will increase out of W-NW reaching a consistent 20-30 mph by this afternoon. High clouds will remain over our area for the remainder of the day, but no precipitation is expected. Temperatures will gradually start to increase by Friday.The Gallatin and Madison Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
The storms continue to deliver. Over the past 48 hours, more than two feet of snow has fallen around West Yellowstone with a snow water equivalent (SWE) totaling more than 2.5 inches. Snow totals thus far are closer to a foot and a half around Cooke City and six to eight inches in the Northern Gallatin and Madison Ranges. The recent snow totals alone are enough to make my internal avalanche alarm go off. The snowfall combined with consistent 30 mph winds gusting to 50 mph is making the alarm sound more like a tornado siren. Multiple observations and reports from ice climbers in Hyalite Canyon are backing this uneasy feeling. One climber triggered a dense wind slab 8" deep and thirty feet across - luckily he was not caught. Another set of climbers witnessed multiple avalanches pour down the Scepter, a popular ice climbing route. One of the avalanches was described as "a slide that rivals any I have seen in movies". This is a poignant reminder of the building avalanche danger. Let's not forget Guy Lacelle who was caught and killed by an avalanche while climbing in Hyalite Canyon around this time last season. As the Thanksgiving holiday approaches, many winter enthusiasts will be taking full advantage of the early season powder. This time of year can be exceptionally dangerous since our avalanche brains are a little rusty - it's easy to suffer avalanche blindness due to powder fever. Slow down and remember what's happening. A copious amount of fresh snow accompanied by strong winds has heavily loaded leeward slopes increasing the avalanche danger. Human triggered avalanches are likely on all slopes that have received recent wind loading and careful evaluation of weather and snowpack combined with conservative decision making is essential. Backcountry travelers should be equipped with the proper rescue gear and know how to use it. Due to the abundant snowfall and strong winds over the past few days the avalanche danger is rated HIGH on all wind loaded slopes. All slopes that have not received wind loading have a CONSIDERABLE avalanche danger. The Bridger Range The Bridger Range has been favored less during this past system receiving only a fraction of the snow totals the southern mountains picked up. Over the past two days the Bridgers received 2-4 inches of light density snow with moderate ridgetop winds. The reduced amount of snow and wind has limited slab development as well as the amount of stress being applied to the snowpack. Yesterday was the first day the Bridger Bowl Ski Patrol did control work with explosives giving the snowpack a true stress test. Results were confined to the new storm snow with pockets of wind slab breaking up to 14" deep. Although the Bridger Range did not get the load the southern mountains did, the possibility of triggering an avalanche remains very real. Wind loaded terrain along ridgelines and gullies are high probability zones for triggering slides. Cautious route finding and conservative decision making is essential when traveling in the backcountry. For Today, A CONSIDERABLE avalanche danger exist on all wind loaded slopes. A MODERATE avalanche danger exists on all slops that have not received wind loading. Mark will start daily advisories on Friday at 7:30 am. If you have any snowpack or avalanche observations, drop us a line at mtavalanche@gmail.com or call us at 587-6984. Have a safe Thanksgiving Holiday. Upcoming Avalanche Education Basic Avalanche Awareness – Wed & Thurs, December 1 & 2, 7:00pm – 9:30pm at SUB Ballroom B&C; 12/4- Field day at Bridger Bowl (more information) (Prepay $25 fee) Avalanche Awareness for Snowmobilers – Wed & Thur, December 1 & 2, 7pm – 9:30pm at Team Bozeman, 2595 Simmental Way (more information)
The field course will be either Sunday, Dec 5th or 12th depending on snow conditions.