Advisory Archive

Well, that was a fast transition - welcome to winter! Rain switched to snow on Friday night and has piled up across the advisory area. Snowfall totals range from just a couple inches at lower elevations up to 1.5-2 ft at SNOTEL sites (7000-9000 ft) and likely even deeper at higher elevations. Snow water equivalent totals range from 1.7” in the Bridger Range and Cooke City up to 3.4” in Taylor Fork (see the Weather and Avalanche Log for specifics). Snowfall will continue today, favoring the Big Sky area with up to another foot falling by tomorrow morning. Temperatures will stay cool with chances for snowfall continuing through mid-week.

Change is coming. The beautiful fall weather we’ve been basking in is coming to an end. A pattern shift will occur this weekend. Expect colors in the mountains to shift from green and gold to white. For current weather data check our weather stations in Cooke City, Hyalite, Lionhead and our new station on Sawtelle Peak near Island Park, ID., as well as Bridger Bowl’s weather stations, and SNOTEL sites throughout our advisory area. As snow begins to fall we’ll update the Weather and Avalanche Log daily and issue pre-season bulletins as needed.

Spring weather can be highly variable and create a mix of avalanche problems to watch for. Snow conditions and snow stability can change drastically from day to day or hour to hour. Anticipate rapid change and plan accordingly. Plenty of snowfall over the winter with more spring snow to come makes avalanches possible into summer.

Unsettled weather beginning Wednesday brought a couple inches of snow to the mountains around Bozeman and Big Sky, with 5-10” near West Yellowstone and Cooke City. At lower elevations this precipitation fell as rain. Heavy snowfall is expected today around Bozeman and Big Sky with 4-8” falling by the end of the day. Only an inch or two will fall around West Yellowstone and Cooke City. Tomorrow will be sunny with temperatures above freezing. Sunday will be cloudy again with a sprinkling of snow possible.

Between Thursday night and Sunday morning, a large spring storm left 1-2 ft of fresh snow across most of the advisory area (Lionhead only received a few inches). The storm system moved out yesterday, with skies clearing and temperatures rising above freezing. Today will be mostly sunny with mountain temperatures in the 40s and 50s F. Clouds will move in for most of the rest of the week, but there will also be sunny periods mixed in. High temperatures will be in the 40s F. There are chances for light precipitation starting on Wednesday, but it won’t amount to more than a few inches of snow.

We are at the leading edge of a significant spring storm. Temperatures on Friday morning are in the 20s F with 5-15 mph winds from the west to southeast. Overnight, the mountains received 2-5” of snow except in the West Yellowstone area where precipitation began as rain. Snow and wintery weather will persist through Saturday night with high temperatures in the 30s F and 5-20 mph winds from the north to northwest. By Saturday night the mountains will receive 10-20” of new snow with areas like the Northern Gallatin Range potentially getting more. The sun will come out on Sunday with slightly warmer temperatures.

Since Friday the mountains near Cooke City got 13” of new snow, and near Bozeman, Big Sky and West Yellowstone got 4-6”. Temperatures reached mid 30s F on Saturday and high 20s F yesterday. Wind was west-southwest at 15-25 mph with gusts of 30-60 mph. Today under mostly sunny skies, temperatures will reach mid-40s F, and wind will be 5-25 mph out of the west-southwest. Wind will remain west-southwest through the week with periods of moderate to strong speeds. Temperatures will drop to the teens and 20s F most nights and during the day will reach mid-30s to low 40s F. Tomorrow there is a chance for 1-4” of snow with more possible Thursday night and Friday.

Since Monday, the mountains have received 1-1.5 ft of new snow. Winds have been strong and shifting, including some unusual east winds. Skies stayed mostly cloudy and high temperatures stayed below freezing. This weekend, skies will remain mostly cloudy, high temperatures will be a few degrees warmer (but still unseasonably cool), and snow showers are possible (particularly on Saturday night). Total accumulations will likely be only 2-4” by Monday.

On Monday morning, mountain temperatures are in the single digits to mid-teens F with west to southwest winds blowing 5-15 mph. Sunday night the mountains received 1-2” of new snow. A significant spring storm will move into Southwest Montana Monday afternoon through the middle of the week. Daily high temperatures will be in the teens to 20s F with 10-20 mph winds. The mountains will likely get 10-20” of snow through Wednesday when the storm lightens.