Advisory Archive

The well-advertised winter storm has finally arrived. Unfortunately, Snotel sites are still down and we don’t have access to snow totals in the mountains around West Yellowstone and Cooke City. Ski resort weather stations are still working and Big Sky is reporting 7-9 inches on new snow over the past 24 hours while Bridger Bowl is reporting close to 5 inches. Looking at some webcams it doesn’t appear that the mountains around Cooke City and West Yellowstone received any more snow than the ski resorts.

At 4 a.m., mountain temperatures are in the low to mid 20s F and winds are blowing 5-15 mph. In the Bridger Range winds appear to be coming out of the E-NE while in the mountains south of Bozeman winds are blowing more out of the S-SE.  Either way, east winds rarely equate to heavy snowfall so I’m a bit pessimistic as to how much more snow will actually accumulate. The National Weather Service is forecasting 2-4 inches today and 2-4 inches tonight over the advisory area. Along with falling snow, temperatures will drop throughout the day and will be in the teens by this evening. Winds will remain light to moderate out of the E,NE and SE.

At 5 a.m. a trace to one inch of new has fallen in the mountains around Big Sky and West Yellowstone. Temperatures range from the mid-teens to low 20s F and winds are blowing 15-30 mph out of the W-SW with gusts near 50 mph being recorded around Big Sky. Today will be a transition day as a strong winter storm moves into the area. Moderate to strong W-SW winds will continue to impact the area and temperatures will warm into the mid to upper 20s F. Light snow will begin to fall by late morning and will increase as the day progresses. The mountains will likely see 1-3 inches of new snow by this evening. Snowfall increases tonight with another 4-6 inches possible by tomorrow morning. Snow will continue tomorrow with another 4-6 inches possible during the day. This storm has the potential to dump a foot or more by Tuesday morning.

At 4 a.m. no new snow has been recorded. Mountain temperatures range from the mid-teens to low 20s F and winds are blowing 5-15 mph out of the W-SW. Today, a weak ridge of high pressure will produce mostly clear skies during the morning hours, but the ridge begins to break down this afternoon producing partly to mostly cloudy skies by this evening. Temperatures will warm into the mid to upper 20s and winds will continue to blow 5-15 mph out of the W-SW. Wind gust of 20+ mph could impact upper elevations later in the day. A storm system begins to impact the area tomorrow producing moderate to heavy snowfall by tomorrow evening.

Temperatures yesterday were in the 20s F and dropped to the teens this morning. Winds were out of the west around 20 mph with gusts between 50 and 60 mph yesterday afternoon. Average wind speeds this morning are around 15-20 mph. Since yesterday morning, the mountains around Bozeman and Big Sky received 2-3” of new snow and the Lionhead area picked up 5”. With SNOTEL sites still down, I can say at least 5” inches of snow fell in the mountains around Cooke City based on reports from town and webcams. Our next chance for snow will be Sunday. Today will be mostly clear with temperatures in the mid-20s F and wind less than 20 mph out of the west.

Temperatures this morning are in the teens F, and winds last night were westerly between 20 and 30 mph with gusts up to 60 mph. The mountains near Cooke City received 7-9” of snow and the mountains south of Bozeman and near Big Sky received 2-3” of snow. Less than one inch of snow fell in the Bridger Range and mountains near West Yellowstone. Temperatures today will reach the low 30s F. Wind will be westerly at 20-30 mph with gusts up to 50 mph. The southern ranges will receive 3-4” of snow today with an additional 1-2” tonight, and the northern mountains will get 2-3” by morning.

At 4 a.m. it was eerily warm with the bank thermometer across the street blinking 56F. Mountain temperatures are in the upper 20s in the south and mid-30s in the north. All the local SNOTEL sites are down, so I am unable to confirm that it did not snow in the last 24 hours, although ski areas, webcams and deductive reasoning lead me to that conclusion. Winds are another story and ridgeline stations are reporting gusts from the southwest in the high 50s with averages of 30-45 mph. Today will be warm and remain windy as clouds increase with snowfall starting this afternoon. By morning I expect 1-2 inches up north and 4 inches in the south. Colder temperatures arrive with the storm and tonight they will fall into the low 20s.

MOUNTAIN WEATHER

A moist southwest flow hit the southern mountains last night. The mountains around Cooke City, West Yellowstone and Carrot Basin got 10-12 inches of dense snow with 5 inches around Big Sky and only a trace outside Bozeman. Ridgetop winds were hammering out of the west to southwest averaging 20-30 mph and gusts in the 60s. At 5 a.m. snowfall has stopped, skies are mostly cloudy and temperatures are in the mid-20s to low 30s at the ridgelines, 15 degrees warmer than normal. The next 24 hours will continue to be windy and warm with just a few scattered showers. Another pulse of snow is forecasted Wednesday and Thursday.

Snotel sites did not update overnight so I’m uncertain if it actually snowed, particularly in mountains around West Yellowstone and Cooke City. At 5 a.m. mountain temperatures are in the mid to upper 20s F and winds are blowing 15-30 mph out of W-SW with gusts in Hyalite and Big Sky reaching over 40 mph. Today, winds will remain strong out of the W-SW and temps will warm into the upper 20s to low 30s F. Skies will be cloudy as a storm system approaches from the west. Mountain snow showers will develop by this afternoon in the mountains around West Yellowstone and Cooke City. There is a slight chance for afternoon snow showers in the mountains around Big Sky, while the mountains around Bozeman will likely stay dry. By tomorrow morning the southern mountains could see 4-6 inches of new snow with Big Sky picking up 1-3 inches.