Advisory Archive
Yesterday was warm and sunny and a great day to be in the mountains. Winds increased overnight mostly near Big Sky and were blowing 15-25 mph gusting into the 40s from the southwest and west this morning. Under cloudy skies temperatures remained mild and were in the mid 20s F. Mostly cloudy skies will continue today as moisture streams into the area from the southwest with warm air. Temperatures will be in the mid 30s F and winds will blow 20-30 mph from the southwest and west. No snow will accumulate today or this evening; however, Monday evening has a good chance for accumulating snowfall.
Yesterday morning the Bridger Range and northern Gallatin Range received a few more inches of snow at the end of the storm, but snowfall ended quickly and no new snow accumulated overnight. Winds this morning were blowing 8-25 mph from the west and southwest with mountain temperatures near 10 degrees F around Bozeman and Big Sky and single digits near West Yellowstone and Cooke City. Valley temperatures are colder in most areas especially West Yellowstone where they are about 20 degrees below 0 F. Today will be similar to yesterday under a ridge of high pressure with mostly sunny skies. Air temperatures will only reach the 20s F but will feel much warmer and should be significantly warmer tomorrow as warm air approaches from the south. Winds will blow 15-20 mph at ridgetops from the west southwest.
After about a six week vacation, Old Man Winter is back. There was a short break in snowfall yesterday morning, but it kicked back in by midday. By 4 am we’ve received about 8 to12 inches of new snowfall throughout our advisory area, with a bit more than that falling in the mountains around Cooke City. The main storm is now east of us, but we’ve still got some energy and moisture wrapping around and putting us in a northwest flow, which is allowing the Bridgers to squeeze every last inch out of the storm. Snowfall is currently stopping in most areas, but the Bridgers could pick up another 3 to 6 inches this morning. Winds started out of the southwest, but have shifted to the west and northwest and are currently blowing up to 20 to 30 mph on the ridgetops. Temperatures dropped overnight into the single digits. A high pressure ridge is pushing in today, bringing clearing skies, moderating winds, and mountain temperatures in the upper teens and low-20s.
Feeble winter weather has come to southwest Montana with temperatures in the mid 20s F and southerly ridgetop winds blowing 15-30 mph this morning. Cloudy skies today will produce snow with 2-4 inches accumulating by tomorrow morning. Mountain temperatures will remain in the 20s and mostly calm southwest winds will blow 10-20 mph shifting to the west. Tomorrow snowfall will end and a small ridge will bring dry weather for the rest of the weekend.
Strong winds will be the main weather event today. At 4 a.m. ridgetop winds were blowing 20-40 mph from the west in the Bridger Range and southwest elsewhere. Temperatures were in the upper teens except near West Yellowstone where they were in the upper single digits. Since yesterday morning a trace to 1 inch of snow accumulated near Bozeman, Big Sky and Cooke City, and these areas should get an additional 1-2 inches by tomorrow morning. 4-5 inches of snow accumulated near West Yellowstone and the southern Madison Range since yesterday. These areas should receive 3-4 inches by tomorrow morning. Temperatures at 9000ft will be in the low 20’s F and winds will blow 30-40 mph from the west-southwest with gusts in the 50’s.
Over the past 48 hours, 10 inches of snow has fallen in the mountains near West Yellowstone, and 7-8 inches has fallen elsewhere. This new snow combined with snow already on the ground provides more than enough for an avalanche, especially if strong winds have formed wind slabs. The new snow will be found on a variety of surfaces that can range from bare ground to weak faceted snow. Regardless of the underlying surface, avalanches are most common immediately after a storm.