Advisory Archive

We’ve had a bit of a break in snowfall since yesterday morning. Overnight only the southern Madison Range and the mountains around Cooke City and West Yellowstone picked up snow, receiving anywhere from 2 to 4 inches. Storm totals from Wednesday through Thursday morning are impressive, with mountain locations picking up 1.5 to 2.5 feet of new snow containing from 1 to 2.5 inches of snow water equivalent. Winds have also been a big part of the equation. Ridgetop winds have been 20 to 30 mph, while our weather instrumentation is also showing strong winds at lower elevation locations yesterday and through last night. Today we’ve got another band of moisture moving through. Most of the storm energy is west and south of us, but we should still receive snow. Snow is just starting this morning, and I’m expecting it to end by late-afternoon. Our northern areas should pick up 3 to 6 inches of new snow, while southern areas will get anywhere from 6 to 10 inches. Winds should decrease from yesterday, but will still be about 10 to 20 mph on the ridges.

The weather station reports took a bit of deciphering this morning to separate out the rain and snowfall. Since early yesterday morning five inches of snow fell in the Bridger Range while one inch dropped around Big Sky and other northern areas. Six inches are in the mountains outside West Yellowstone and ten new inches are in Cooke City. Wind speeds have calmed to 10-20 mph from the southwest with temperatures in the low to mid 20s. Winds will pick up this afternoon as a few more disturbances roll through and drop snow. I expect one to three inches in the north and almost eight inches in the southern mountains by morning.

The mountains around West Yellowstone picked up an inch of snow last night. Under cloudy skies temperatures are unseasonably warm with readings of 30 degrees at 9,000 feet and 41 degrees at the bank thermometer I see out my office window. Today will remain warm with mountain temperatures reaching the high thirties as strong winds continue to blow from the southwest at 20-30 mph. A moist flow will keep skies mostly cloudy with a quick shot of precipitation this morning and again later this afternoon. It’s already raining in Bozeman. Yuk. Luckily, higher elevations are colder and should get 1-3 inches of snow by tomorrow morning.

The ridge responsible for yesterday’s warm sunny weather is finally showing signs it will depart the area and allow moisture to enter. This morning at 4 a.m. mountain temperatures were hovering on either side of freezing and winds were 10-30 mph from the southwest. This southwest flow will bring more warm air with high temperatures near 40 degrees F and winds will continue blowing 10-30 mph. Skies will become more cloudy throughout the day with snowfall beginning this evening. Most of this moisture will be near the mountains around West Yellowstone where 2-4 inches of snow will fall by tomorrow morning. The rest of the area may receive an inch. Fortunately colder temperatures and more snow looks promising later this week.

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.