Advisory Archive
Yesterday's cold front dropped temperatures and a bit of snow. Those watching the thermometer saw it plummet from the 20s to the single digits in three hours. This quick blast of snow added another 3-5 inches from Lone Peak to the Bridgers while the southern mountains got 1-2 inches. Winds are currently west to north at 10-15 mph and should remain light through Friday. Skies will become clear and sunny until Saturday when another band of snow looks on track to hit us. Daytime temperatures will reach the 20s, but dip to below zero in the evenings.
A nice shot of snow Friday night into Saturday dropped 4-5 inches from Big Sky to the Bridgers. Only 1-2 inches fell in the southern ranges. Warm temperatures and sunny skies followed this storm making for a great weekend to get out and burn off some holiday cheer. The existing ridge of high pressure will begin to break down today as a cold front approaches from the the north. This system will bring more blow than snow, but accumulations of 2-4" can be expected in the upper elevations by Tuesday afternoon. Winds will become strong by tonight and could produce gusts up to 50 mph with the frontal passage. Conditions will improve by Tuesday afternoon, but lingering clouds and strong ridgetop winds will impact our area through Wednesday. Partly cloudy skies and cooler temperatures can be expected until the weekend.
Southwest Montana has remained in the grip of a northwest flow. Since Monday a trace of new snow fell with westerly ridge top winds blowing up to 30 mph. Winds and cloud cover will decrease as a ridge of high pressure pushes in from the west. Thanksgiving day looks like the best weather day of the week with clear skies and highs reaching into the 40's F. Winds should remain calm today, but are forecasted to blow westerly at 20-30 mph Wednesday night into Thursday. The next possible shot of snow will be Saturday night into Sunday.
Southwest Montana got a nice shot of winter over the weekend. A moist cold front came through in two distinct waves. The first came in Friday night into Saturday with the second showing up on Sunday morning. These two bouts of precipitation delivered a total of six to eight inches of snow in the Bridgers and the Northern Gallatins. Big Sky, Moonlight and the Yellowstone Club picked up around eight to ten inches. The Southern Madison Range and mountains around Cooke City recorded the most with ten to twelve inches. Lingering energy will continue to move through the area giving the mountains a slight chance of precipitation today and tonight. Moderate to strong winds will continue to blow along the ridge tops, but will die down this evening. A ridge of high pressure will build on Tuesday giving us dry and warm conditions through Thanksgiving.
No new snow has fallen since our last bulletin on November 12. Ridgetop winds were strong last weekend, but calmed throughout the week. Currently they are blowing west to southwest at 15-25 mph. Today a front is approaching from the southwest bringing cloudy skies. Tonight and tomorrow morning snowfall is expected with another storm arriving later Sunday. I'm expecting a total of 4-6 inches of new snow in the mountains by late Monday. Temperatures will dip into the teens and rise into the high 20s over the weekend and winds will continue to be breezy out of the west.
Welcome back winter! Southwest Montana has become the epicenter of a strong cold front passing over the Northern Rockies. This front has delivered widespread precipitation with the Bridgers and mountains around Cooke City receiving the most with 12-16 inches of snowfall. Accumulations in the Northern Gallatins were eight to ten inches with West Yellowstone measuring around six inches. As this strong upper level trough is pushed to the east, we can expect snowfall to taper off this evening. Clearing skies and colder temps will prevail through mid-day Friday with another round of moisture moving into the area late Friday night into Saturday. Saturday night into Sunday should stay dry with below average temps.
The start of November received a break from what seemed like an early arrival of winter during October. Nearly 2.5ft of new snow fell last week in the mountains around Bozeman and Big Sky, while the mountains near Cooke City and West Yellowstone received 6-9 inches. That snow has settled to a total snowpack depth of 20-22 inches near Bozeman and Big Sky and 7-17 inches near Cooke City and West Yellowstone. Warm sunny days and clear cold nights will continue until this weekend when some precipitation will be possible.
October continues to blanket the advisory area with snow. This morning the mountains around Bozeman and Big Sky had 7-8 inches of new snow, and the mountains around Cooke City and West Yellowstone had 2-4 inches. Ridgetop winds have been ripping from the west and northwest at 26-30 mph in the Bridger Range and 18-20 mph near Big Sky. Temperatures at 9000ft have warmed close to freezing and will stay there until late Saturday night when they will start to cool again. Precipitation will continue through the weekend. Above 9000ft several inches of snow may accumulate each day, and a mix of rain and snow will likely fall at lower elevations. Strong winds will continue blowing from the northwest and west possibly calming late Saturday night.
October has been cold and wet. Most river basins in Montana have above average snowpacks:
http://www.wcc.nrcs.usda.gov/cgibin/snowup-graph.pl?state=MT
Average daily temperatures have been below normal:
Overnight up to 2ft of snow has fallen in the Bridger Range, 12-16 inches near Big Sky, and 4-5 inches in the mountains near Cooke City and West Yellowstone. Northerly winds have been blowing 12-15 mph with gusts up to 38 mph. October has been especially cold and snowy with preliminary climate data indicating Bozeman may experience its coldest October on record beating 1969 for the coldest daily average temperature. Precipitation has been above normal with MSU recording an additional ½ inch of water above the monthly average.
Early season new snow and record low temperatures at the beginning of October are a bad mix. Weak, faceted snow develops in these conditions which can increase the avalanche danger with subsequent snowstorms.
