Advisory Archive
Over the past 24 hours the Bridger Range picked up 15-18 inches of low density snow while the rest of our advisory area picked up 4-6 inches. Winds are currently blowing 20-30 mph out of the WNW with gusts reaching into the 40s at Big Sky and Hyalite. Mountain temperatures are in the single digits to low teens. Today, winds will continue to blow 20-30 out of the WNW and temperatures will warm into the upper 20s F. Snow showers will continue through the morning hours with additional accumulations of 3-5 inches possible by this afternoon. Skies will become partly cloudy by this evening and dry conditions will exist through tomorrow.
Since yesterday morning most areas received 2-3 inches of snow, except Lionhead which received 4 inches of new snow, and Bridger Bowl which had received 8 inches of very low density snow by 7 a.m. Temperatures this morning were near 0 degrees F and winds were blowing 10-20 mph from the W and NW with gusts of 30 mph. Today temperatures will struggle to reach the low teens F. Winds will continue from the W and NW averaging 15 mph and gusting 25-30 mph.
Snow should end this morning allowing some sunshine today but snowfall will return late this afternoon or this evening and be snowing tomorrow morning. By tomorrow morning the mountains near Bozeman will get another 4 inches of new snow, the mountains near Big Sky and Cooke City will get 2-4 inches, and the mountains near West Yellowstone will get 1-3 inches. Saturday will be warmer and windier.
Since yesterday afternoon the Lionhead area received 6-8 inches of new snow, the mountains near Cooke City and the Taylor Fork received 6 inches, and the mountains near Big Sky and Bozeman received 3-4 inches. Yesterday strong westerly winds averaged 20 mph with gusts of 40 mph. This morning temperatures dropped into the single digits F and will rise into the teens F today. More snow will fall with 2-4 inches accumulating by tomorrow morning. Winds will blow from the W and SW averaging 10 mph and gusting to 20 mph.
Yesterday two inches of snow fell in the southern mountains while the northern areas got a trace to one inch. Temperatures are in the high single digits this morning with increasing southwest winds. Currently ridgetop winds are averaging 20-30 mph with gusts near 45 mph. Clouds will increase today, temperatures will not rise much and winds will continue to blow strong out of the southwest. Snowfall will start later this morning with accumulations of 2-4 inches in the southern mountains and 1-2 inches up north.
In the last 24 hours a trace to one inch of snow fell in the southern mountains. Temperatures are near 10F and east winds are light at 5-10 mph. Today will be cloudy with snow showers near West Yellowstone and Cooke City while the rest of our area enjoys mostly sunny skies. Winds will shift to the northwest today, but remain light as temperatures rise into the high teens. By morning I expect 2-3 inches in the southern mountains.
Since yesterday morning a trace to one inch of snow fell in most areas with the exception of the Bridger Range which picked up an additional 3-5 inches between 7 am and noon yesterday. Winds have been decreasing over the past 24 hours and are currently blowing 5-15 mph out of the SSE. Temperatures are in the single digits under mostly cloudy skies. Today, temperatures will warm into the low twenties F and winds will gradually shift to the SW blowing 5-15 mph. Skies will be partly cloudy in the north, but a weak weather disturbance in the south will produce a chance of snow showers for the mountains around West Yellowstone and Cooke City, 1-2 inches is possible by this afternoon. An unsettled weather pattern will remain over the southern mountains through tomorrow, but the north will stay mostly dry.
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, 5-7 inches fell elsewhere. Winds blew 30-40 mph out of WNW during the storm, but have decreased to 20-30 mph out of the WNW. The exception is the Bridger Range where ridgetop winds are still blowing 30-40 mph. Mountain temperatures are ranging between 5-10 degrees F under cloudy skies. Today, temperatures will warm into the mid to high teens and winds will gradually decrease to 15-25 mph out of the west. Lingering snow showers could produce 1-2 inches of new snow by this afternoon, but conditions will dry out by this evening.
Since yesterday a few places near Cooke City and West Yellowstone received a trace of new snow. This morning ridgetop temperatures were in the mid teens F and W/SW winds were blowing 20-30 mph with gusts up to 60 mph. Today will be cold, windy, and snowy. Temperatures may climb a few degrees this morning before cold air moves into the area. Winds will blow mostly from the W at 25-40 mph. Snow will start falling early this morning. By tomorrow morning 4-6 inches will accumulate near Cooke City and West Yellowstone. Further north near Bozeman and Big Sky, 2-4 inches will accumulate.
Lingering snowfall yesterday produced 2-3 inches in most areas. Last night winds increased blowing 20 mph and gusting to 40 mph from the W. This morning winds calmed and were blowing 10-15 mph with gusts of 25 mph. Temperatures were in the single digits to low teens F. A short-lived, upper level ridge will bring dry weather today with a mix of sun and clouds and temperatures near 20 degrees F. Winds will remain about the same speed but shift to the SW as a trough of low pressure approaches tonight. Snowfall will begin tomorrow morning.
In the last 24 hours the heaviest snowfall occurred in the Bridger Range and the mountains near Cooke City. Yesterday’s snow was wet and heavy while snow that fell late last night had a much lower density because temperatures dropped into the low teens and single digits F. The exact amount of snow is hard to gauge, but the snow water equivalent (SWE) is measured exactly and tells how much weight was added to the snowpack:
- Near Cooke City 1 inch of SWE (5-10” of snow)
- In the Bridger Range 0.5 - 0.9 inches of SWE (3-5” of snow)
- Near Big Sky, Hyalite, and West Yellowstone 0.4 to 0.6 inches of SWE (2-4” of snow)
- Near the Taylor Fork 0.2 inches of SWE (1-2” of snow)
Further complicating snowfall totals is yesterday’s extreme winds which averaged 50 mph from the W with gusts of 60-90 mph. This morning winds were blowing 15-20 mph from the WNW with gusts of 40 mph. Today will be mostly cloudy with an additional 2-4 inches of snow falling. Temperatures will warm into the high teens F.
