GNFAC Avalanche Forecast

This week started with a decent storm that dropped up to 5-7 inches of snow containing a lot of water. Another 2-5 inches of snow fell Tuesday night, and some places were dusted Wednesday night. At most upper elevation SNOTEL sites, the snowpack has reached its peak water content which should start quickly going down in coming weeks.  In the springtime battle between winter and summer, it seems like summer is starting to win more lately…but last year the final snowfall in Bozeman was on June 17th. Temperatures - Air temperatures in the mountains dipped below freezing Tuesday and Wednesday nights. Last night (Thursday night), low temps were on either side of freezing, but clear skies should have helped refreeze the snowpack a little but. This weekend and early next week - An upper level ridge of high pressure will bring warm, sunny weather today, Saturday, and Sunday morning. Clouds and rain arrive Sunday afternoon, but cold air doesn’t arrive until Monday morning with winds from the north that shift to northeast and east. Snow should fall Monday morning through Tuesday morning. Most places should only get an inch or two of snow, but there may be isolated spots (Tobacco Root Mtns maybe?) that could get 5-8 inches.

This is a volatile week in the battle between winter and summer. With temperatures in the upper 20s to low 30s F, a wet spring snowstorm is impacting the area to start off the work week, with the Bridger Range receiving the most significant precipitation. As of Monday, at 6 AM, the Bridger Range has received a whopping 1.3” of snow water equivalent (SWE) in the last 12 hours, with a more nominal 7” of snow at the Alpine Weather Station. The Red Chair Cam at Bridger Bowl shows 14” of new snow. The mountains near Cooke City, Big Sky, including the Taylor Fork, and south of Bozeman have received 0.5” of water with 0-5” of snow (meaning it rained in some areas). Light rain fell in West Yellowstone and Island Park. The first storm of the week winds down Monday evening after an additional 1-4” of snow falls during the day. Tuesday will be warm and dry, but rain and snow return to the area Tuesday night through Wednesday. The tail end of the week will be lovely spring weather with mountain temperatures pushing into the 50s and low 60s F.

Since Monday, 2-3” of new snow have fallen in most of the advisory area, with no new snow around Bozeman. Winds have been generally easterly and moderate for the last couple days. Temperatures have been rising into the 30s and 40s and dropping below freezing at night. Today will be mostly sunny, with high temperatures in the 40s F. There may be some thunderstorms this afternoon, particularly around Island Park and West Yellowstone, but any accumulations will be minimal. Tomorrow will bring a mixed bag of spring weather. Temperatures will be a little warmer than today and there will be sun, clouds, and maybe some snow or rain showers - but again, not big accumulations. Sunday will be cloudy, with snowfall starting later in the day. There could be some substantial snowfall Sunday night into early next week, but exact amounts are still quite uncertain at this point.

This morning there is 4-5” of new snow in the Bridger Range, Hyalite and Cooke City, 1-2” near Big Sky, and none elsewhere. Wind has been out of the west and southwest at 5-15 mph with a few gusts of 25-40 mph. Temperatures are 20s to low 30s F. Today, under mostly cloudy skies, temperatures will reach low to mid-30s F with light snow showers, and some thunder possible this afternoon. Tonight temperatures will drop to the teens and low 20s F. Wind will remain light to moderate out of the west. There is a chance for 1-3” more snow by this evening near Bozeman and Cooke City.  Tomorrow skies will be mostly sunny, and the rest of the week skies will be partly sunny to mostly cloudy. During the middle of the week, daytime temperatures will reach 30s to low 40s F with overnight lows in the 20s F. There is a chance for light snow on Tuesday night and Wednesday with 1-2” possible. At the end of the week temperatures will warm to high 40s F with chances for rain and snow to start the weekend, then temperatures cool with higher chances for snow next Sunday and Monday.

This morning there are 1-2” of new snow near Big Sky and in the Bridger Range with zero to a trace elsewhere. Temperatures are mid-20s to low 30s F. Wind has been from the northwest and southwest at 5-15 mph with gusts of 20-35 mph. Today will be a spring mix with temperatures reaching 30s to mid-40s F under mostly cloudy skies. The sun might show briefly before some light showers (maybe rain, then snow) and possible thunder this afternoon. Wind will be generally light with some moderate gusts out of the west. By tomorrow morning 2-4” of new snow are possible near Bozeman, Big Sky and Cooke City with less elsewhere. More snow is forecast tomorrow into Tuesday.

Temperatures are in the teens and 20s F early this morning. Winds are mostly light out of the north and west, but a little stronger in the Bridger Range, gusting up to 35 mph. There hasn’t been any precipitation in the last 24 hours.  Today will start out mostly sunny, with clouds moving in later this afternoon around Bozeman and Big Sky. Temperatures will rise into the high 30s and 40s F. Mostly light west winds will continue today. Overnight, skies will cloud up everywhere and snow showers will drop a trace to 2” of new snow.  Snow (and lower elevation rain) showers will continue tomorrow before more substantial snowfall kicks in Sunday night into Monday.

Since yesterday morning, 3-6” of new snow fell around Big Sky and West Yellowstone, with 1-2” across the rest of the advisory area. Winds are 5-10 mph out of the north and east, with gusts up to 30 mph. Temperatures this morning are in the single digits and teens F. Today will be mostly sunny, with any lingering clouds clearing up by mid-morning. High temperatures will be in the 20s and 30s F. Light winds will continue out of the north and east, blowing a bit harder around West Yellowstone and Island Park. Expect sunny skies again tomorrow with temperatures rising a bit higher before snowfall returns on Sunday and Sunday night.

Winter is back with a vengeance as temperatures started plummeting yesterday around 5pm and it’s snowing hard this morning. Temperatures this morning are mostly in the mid teens F. Winds this morning are blowing 5-10 mph gusting to 20 mph at ridgetops mostly from the north except in the Bridgers where winds are coming from the east with gusts hitting 40 mph. 6am snow totals are: 7” snow (0.6” water) - Bridger Range 5” snow (0.5” water) - Cooke City area 3” snow (0.2” water) - Big Sky area no new snow near West Yellowstone and Island Park Today will be cold, cloudy, snowy, and windy as the center of a low pressure trough circles overhead. Expect winds to increase by midday blowing from the north-northeast 20 mph gusting to 40 mph. Temperatures will struggle to break into the low 20s F. Snowfall should end tonight with most places getting another 2-4”, but the Bridgers could get a bit more. Clearing skies tonight could allow temperatures to drop into the single digits F.  The Beartooth Mountains and Red Lodge area could do well with snowfall today. (Red Lodge Mountain opens for skiing and riding tomorrow through the weekend) Looking ahead - The jet stream is a bit disorganized with no major systems lined up, but the overall trend through the rest of April is cool and wet. Friday & Saturday have clear skies, then snowfall returns early Sunday morning into Monday.

This morning temperatures are in the 30s F. Yesterday temperatures reached low 40s to mid-50s F. Wind has been out of the southwest, west and northwest at 5-25 mph with gusts of 25-35 mph. There is no new snow. Today, temperatures will reach 40-50 F with increasing cloud cover. Wind will start from the west and southwest at 5-15 mph with gusts of 20-30 mph. This afternoon and tonight the wind will increase and shift to the north and northeast. Some rain and thunder are possible this afternoon with snow expected in the mountains tonight through Friday morning.  By morning, 4-8” of new snow is possible near Bozeman, Big Sky and Cooke City with 1-2” near West Yellowstone and Island Park. By Friday morning 1-2 feet are possible in the mountains near Bozeman and Cooke City with at least 8-12” in most areas.

This morning, temperatures are near 30 degrees F with 5-15 mph winds from the west and southwest. Clear skies overnight allowed longwave radiation to escape into the atmosphere and snow surfaces to refreeze.  Today, temperatures will be 10 degrees F warmer than yesterday, with highs nearing 50 F in Cooke City and rising well into the 50s F across the rest of the forecast area. Winds will be 5-15 mph from the west and southwest. A few clouds will move into the area this evening, but the change in weather arrives tomorrow afternoon when low pressure arrives from Canada and with it, colder temperatures and a chance for more than a foot of new snow.

This morning, temperatures are in the teens to low 20s F with light winds blowing 5-15 mph from the west and the north. The Bridger and northern Gallatin Ranges picked up 2” of additional snow yesterday morning before the weekend’s storm moved out of the area. Today and tomorrow will have similar weather, with clear skies, above-average temperatures, and dry conditions. Today, temperatures will be in the 40s to 50 degrees F, with 5-10 mph winds from the northwest shifting to the southwest. Later this week, an upper-level trough will move south from Canada, bringing colder temperatures and snow to Southwest Montana and Island Park late Wednesday through Thursday. This will be followed by a weekend warm-up and another storm early next week.

Classic spring weather yesterday afternoon delivered snow in the mountains and rain in the valleys accompanied by lightning and thunder. 10” snow (1.1” water) - Cooke City Area 6” snow (0.8” water) - northern Gallatin Range 2-3” snow (0.2-0.3” water) - Bridger Range and Big Sky area Temperatures plummeted overnight and range from around  20° F in the Bridgers to low-mid teens F most other places to single digits F at the highest elevations. Strong ridgetop winds during snowfall yesterday blew 20 mph gusting 40-50 changing directions quickly from S to W to NW. Winds have eased this morning. Today cold air and lingering clouds will remain over the area with a few snowflakes falling in the Bridgers. The sun should start peeking out this afternoon bringing high temps into the mid 30s F in the Bridgers and low to mid 20s F near Big Sky and Cooke City. There will be clear skies and plenty of sunshine near West Yellowstone and Island Park with high temps approaching 30° F. Winds from the WNW will blow in the low teens but could remain a bit gusty in the Bridgers. Looking ahead - A ridge of high pressure brings warm, dry weather Monday & Tuesday. Another trough descends from Canada bringing more snow and cold air on Thursday. The fight between winter and summer continues.

The tug of war between winter and summer continues. Following high temperatures yesterday in the 40s and 50s F, overnight air temps stayed above freezing only dropping into the upper 30s F. Cloudy skies overnight likely prevented any radiational refreezing of the snowpack. Light winds this morning are coming from the southwest  An approaching trough of low pressure will bring a little bit of everything in today’s weather. Temperatures should warm to either side of 40° F this morning before cooling this afternoon when a cold front finally passes overhead bringing cold air by the end of the day.  Winds will increase this afternoon blowing 15-20 mph gusting in the 30s mostly from the southwest but switching to the west-northwest in the mountains near Bozeman.  Cloudy skies will be spitting rain and snow (mostly snow in the mountains) this morning. A bit more snow should fall this afternoon with most areas receiving an inch or so. A few places like maybe near Cooke City and the northern Gallatin Range could get 2-4 inches by tonight, but your guess is as good as mine.

Temperatures did not drop below freezing last night. Early this morning, they are in the high 30s and low 40s F. There has not been any measurable rain or snow. Winds are out of the south and west at 10-25 mph, with gusts as high as 50 mph.  High temperatures today will be in the 40s and 50s F. Skies will start off mostly sunny this morning, with increasing clouds around Bozeman and Big Sky this afternoon. Winds will remain moderate out of the south and west. Rain and snow showers will start overnight. Temperatures will be cooler this weekend and precipitation will continue, on and off, but accumulations are looking modest at this point.

This morning there is no new snow and temperatures are high 20s to low 30s F. Wind is out of the west at 10-20 mph with gusts to 30 mph. Yesterday afternoon winds were moderate to strong out of the west and northwest, averaging 15-35 mph with gusts reaching 50-65 mph.  Today, skies will be mostly sunny with temperatures reaching mid-40s to mid-50s F, and light to moderate wind out of the west-southwest at 10-25 mph. Tonight temperatures will drop to mid-30s and low 40s F under partly to mostly clear skies. Tomorrow will be similarly warm and sunny before cooler, wet and snowy weather arrives Friday night through Sunday morning.

Yesterday’s storm delivered more than expected with snow above ~7,000’ and a mix of rain and snow at lower elevations. Since precipitation began early yesterday, total snow water equivalent (SWE) amounts and estimated snow depths are: 0.9-1.0” SWE with 4-9” snow near Island Park and West Yellowstone. 0.3-0.5” SWE with 3-5” snow in the Taylor Fork, Big Sky, Hyalite, Bridger Range and Cooke City. This morning, temperatures are low 20s to low 30s F, and wind is out of the west and northwest at 10-20 mph with gusts of 20-40 mph.  Today, under clearing skies, temperatures will reach mid-30s to mid-40s F, and this afternoon westerly winds will increase to 15-25 mph with gusts of 30-45 mph.  The next couple days look mostly clear and sunny with daytime temperatures reaching high 40s to mid-50s F and overnight lows in the 30s F. This weekend will have cooler temperatures with a chance for heavy snowfall.

There is a spring mix of weather in the mountains this morning, with temperatures just above and below the freezing line, some rain, some snow and winds blowing 15-30 mph from the west and southwest. There is an inch of new snow in the mountains around Bozeman, Big Sky, West Yellowstone and Island Park. However, in the mountains around West Yellowstone and Island Park precipitation started as rain. Today, high temperatures will be in the 30s and 40s F, with light snow or rain depending where you are relative to the 6000-7500’ elevation freezing line. Winds will be 10-20 mph from the west and southwest, and the mountains may get another 1-2 inches of snow throughout the day. Sun and warm temperatures return tomorrow.

This morning, mountain temperatures mostly dropped below freezing and are hovering in the upper 20s to low 30s F. Winds are 10-20 mph from the west and the south, and there is no new snow. Today, the ridge of high pressure breaks down and increasing clouds will start to shade slopes from the constant spring sun. Temperatures in the Bridger Range will peak in the mid-50s F with highs in the mid-40s F throughout the rest of the forecast area. Winds will blow 10-20 mph from the west and southwest, and light snowfall starting tonight will bring 1-2” in the southern portions of the forecast area and a trace to the northern half of the forecast area by morning. 

This morning temperatures are high teens to low 30s F. Wind has been from the southwest and northwest at 5-25 mph with gusts of 25-35 mph. There has been no new snow over the last 24 hours. Today will be sunny with temperatures reaching high 30s to mid-40s F, 5-10 degrees warmer than yesterday’s high temperatures. Wind will be calm to light, 5-15 mph, out of the west and northwest. Tomorrow looks warmer than today, and tomorrow night colder air brings a chance for light snow showers through Tuesday.

Snow showers yesterday left at most an inch of new snow. Winds are light this morning, out of the north and west. Mountain temperatures this morning are in the single digits and teens F under clear skies. Today will be sunny and 5 to 10 degrees F warmer than yesterday. High temperatures will be in the 30s and low 40s F. Winds will shift more southwesterly today and remain light. The next couple days will remain sunny and warm, before clouds and a chance for precipitation return early next week.