The current avalanche danger for the west central Montana backcountry is MODERATE. Natural avalanches are unlikely and human triggered avalanches are possible in specific areas. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Tuesday, February 23rd, 2016. Weather and Snowpack
The series of light atmospheric disturbances has dissipated and high pressure is setting up over west central Montana. Winds have dropped off and are currently 7mph gusting to 10mph from the south at Deer Mountain. Mountain temperatures are currently ranging from the single digits to the low twenties around Lolo Pass and little to no snow was seen over night.
Tim and I were up at Wisherd ridge yesterday and Travis and Brian were down at Lost Trail over the weekend. We all observed heavily wind affected snow making the primary avalanche concern today windslabs above about 6500ft. Strong winds have been recorded and observed for nearly a week blowing primarily from the south and west. With minimal snow for transport windslabs have been found to be small and soft but widespread on aspects ranging from NW-SE. The variability of the windslabs is deceiving and small wind loaded pockets are easily missed especially on cross loaded terrain. Look carefully for any indications that a slope or terrain feature may be wind loaded.
Multiple skier trigger slides were observed and reported over the last few days in the northern half of the advisory area, primarily in the Rattlesnake. These slides were occurring on the interface of the new snow and the old snow surface. This interface is slowly settling out but may required a few more days before it is no longer reactive. The layers of graupel above the melt freeze crust and facets below the melt freeze crust are becoming less reactive as well but still warrant careful evaluation before jumping onto a slope. If the graupel or facet layer does fail it will be significantly larger than the slides that have been triggered over the last few days with the potential for high consequences. Avalanche and Weather Outlook
As the high pressure system sets up over the region warm and relatively clear days are expected for the majority of the week. If cloud cover stays minimal cold clear nights will lead to surface hoar development which can be problematic when snow returns and buries this weak layer. Another possible concern with the warm and clear weather will be cornice fall. Travis and Brian observed the remnants of a natural cornice failure near Lost Trail and with the current forecast there will be potential for more of them so give cornices wide berths.
Travis will issue the next avalanche advisory on Thursday.
The current avalanche danger is LOW in the west central Montana backcountry. Conditions are generally safe but it is possible to find unstable snow in isolated areas particularly on shaded terrain steeper than 35 degrees above 7000 feet. There is always some chance of triggering an avalanche if you recreate or travel on slopes 35 degrees and steeper.
Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for February 25, 2016. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Mountain temperatures are 14 F to 24 F. Winds are 18 mph with gusts of 21 mph out of the West. The area has reported a trace amount of snow. The above average temperatures today will again feel like spring in the mountains.
Tim, Steve and I toured in the Rattlesnake yesterday and we found a very well bonded snowpack. The interfaces of old and new snow was not reactive in our snowpack tests. The main avalanche problem’s are loose dry avalanches on shadier aspects and loose wet avalanches on sunnier aspects in the afternoon. These are not very big, but can pose a problem if they knock you off your feet and take you into a terrain trap (tree, cliff, or gully).
The final problem is cornice failure. The cornices grew over the weekend and with the temperatures rising in the afternoon give them a wide berth and do not recreate beneath them.
There are facets in our snowpack, they have not been reactive in our snow pit tests. I would dig a pit and look for these layers to see if they are reactive in my tests on any steep slope I was planning to recreate on. Weather and Avalanche Outlook
High and dry is the forecast today. The temperatures are supposed to get into the high 30’s today. The next chance for precipitation is for Saturday. A cold front is predicated to move into the area Saturday morning and bring snow with it. The avalanche hazard will remain the same until we have a weather shift.
Ski and ride safe. I will issue the next advisory on Saturday.
The current avalanche danger is MODERATE in the west central Montana backcountry. Human triggered avalanches are possible. Heightened avalanche conditions exist in isolated terrain. Evaluate snow and terrain carefully and identify features of concern.
Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for February 27, 2016. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Mountain temperatures range from 32 F to 40 F in the region. Most sites did not get below freezing last night. Winds are 5 mph with gusts of 6 mph out of the WNW in the Bitterroot and Point Six in the northern part of the advisory area is 24 mph with gusts of 31 mph. The forecast area received 1 to 2 inches of new snow in the last 24 hours. Snotels are reporting .20 and .40 SWE in the region.
Logan and I toured in the Lolo Pass area yesterday on sleds. It was spring. Today a warm system is pushing into the advisory area. This will bring precipitation and strong winds. The snow level will start around 6500 feet and then slowly drop to around 4500 feet. The question will be how the new snow bonds to the the old snow surfaces? On solar aspects we have a melt freeze crust and on some leeward slopes we have old windslabs. Logan and I found broken down surface hoar on our tour. In higher elevations on shadier aspects, the surface hoar may not have been broken down and may be buried by the new snow.
The first avalanche problem will be loose dry or wet avalanches depending on elevation. These should not be very large but can be a problem if you are knocked of your feet and carried into a terrain trap(tree, cliff, or gully).
The second avalanche problem will be windslabs. Leeward terrain will be suspect. These windslabs will be deposited on a variety of old snow surfaces(melt freeze crust, old wind slabs, cold snow on north aspects).
The last avalanche problem is cornice failure. Cornices have been weakening over the last couple of days and with continued warm temperature and new loading will continue to lose strength . Give cornices a wide berth, they break farther back then anticipated.
There are still some facets and the graupel sitting above a melt freeze crust to be found in our snowpack. These layers have not propagated in any of our tests recently, but with a new load may become reactive. Dig a pit and find out what is under your feet on the slope you are choosing to recreate on. Weather and Avalanche Outlook
This system is expected to last till Sunday. The snow levels will drop over the weekend to 4500 feet. In the mountains snow totals will be around 2 to 6 inches. This system is warm and the snow will be wet and heavy. This system has high winds with it. The avalanche hazard will increase with the addition of new snow and high winds.
Thank you to everyone who has sent public observations in. If you see something out there, please send us a public observation.
Ski and ride safe. Logan will issue the next advisory on Tuesday.
The current avalanche danger in the west central Montana backcountry is MODERATE for wind loaded terrain above 6,500ft. Natural avalanches are unlikely but human triggered avalanches are possible in specific terrain. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Tuesday, March 1st, 2016. Weather and Snowpack
Strong westerly winds and light snow have been seen across the advisory area over the last few days. Winds peaked Sunday night and into monday morning with both Deer Mountain and Point Six recording gusts over 50mph. Winds have settled but are still strong, and are currently registering 19mph and gusting to 28mph from the SW. The majority of the advisory area did not see snow overnight with the exception of a trace to an inch near Lost Trail Pass.
Tim and I were in the Rattlesnake yesterday and saw the results of the strong winds over the last few days. Minimal snowfall limited the amount of snow available for transport and slowed the development of windslabs. Windslabs are still the primary concern on leeward terrain above 6500ft. Windslabs are relatively shallow given the winds that have been recorded but are sitting on bed surfaces of crusts on many lee aspects. Careful travel on wind loaded terrain will be essential today.
The secondary avalanche concern today will be loose avalanches. A thin veil of soft snow is sitting on a well-formed crust in many areas and will readily move on steeper terrain (pic). Avoid areas susceptible to loose snow avalanches that also have terrain traps that increase the consequences of getting caught.
Tim and I also observed the debris from old wet slides (pic1) (pic2) that probably occurred mid-week last week. With the mild temperatures that we have been seeing wet slabs may become a problem if warm days also have significant solar radiation warming the snow surface. Stay aware of weather conditions as they change and how they affect the snow. Avalanche and Weather Outlook
Mild temperatures are expected to persist for the next few days. Light pulses of snow will periodically move through the area with a chance of snow coming tonight as the first wave of moisture passes through. Conditions will most likely remain the same in terms of avalanches unless one of the waves of moisture brings a significant new load or wind loading significantly increases.
The next avalanche advisory will be issued on Thursday.
The current avalanche danger is MODERATE on wind loaded terrain above 6,500ft in the west central Montana backcountry. Human triggered avalanches are possible in specific terrain. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Thursday, March 3rd, 2016. Weather and Snowpack
Strong winds continue to persist throughout the advisory area. No new snow was seen overnight but moderate snowfalls yesterday brought an additional 2-6inches of snow since Tuesday morning. Current mountain winds are in the teens and gusting to the twenties from the SE-SW.
With prolonged strong winds and new snow for transport windslabs continue to be the primary concern throughout the region. Yesterday Tim and I were in the Southern Swan Range and found strong ridge top winds and notable cornice development. We also saw the remnants of a very small natural windslab that released sometime over the last two days.
With the new light snow, loose snow avalanches will be the secondary concern today. Around 2-6 inches of new snow has been seen over the last few days. The new snow will be moving on steeper terrain and in areas where it is sitting on crusts. The majority of loose snow avalanches should settle out over the next day or two, but be cautious of terrain traps or anything that increases the consequences of getting caught.
Lastly persistent slabs still warrant some attention. Generally most of the persistent problems have settled out or have been buried deep enough in the snowpack that they are unlikely to be triggered but we did have a propagation (ECTP 24) on a layer of small facets yesterday on a SE aspect. The small facets below crusts near the surface have been intermittently reactive over the last few weeks, so dig pits and test the reactivity of the persistent layers around the crusts. Avalanche and Weather Outlook
A quick moving band of moisture will bring another round of snow late this morning but will give way to more settled weather this evening and into Friday. Strong westerly winds are predicted to continue but with no significant new load and minimal snow for transport avalanche conditions will remain the same.
Travis will issue the next avalanche advisory on Saturday.
The current avalanche danger is LOW in the west central Montana backcountry this morning and will increase to MODERATE in the afternoon. With rising temperatures and peak solar radiation, steep sun exposed slopes will have the ability to produce loose wet avalanches in the afternoon.
Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for March 05, 2016. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Mountain temperatures range from 32 F to 39 F in the region. Most sites did not get below freezing last night. Winds are 15 mph with gusts of 24 mph out of the SE in the Bitterroot and Point Six in the northern part of the advisory area is 7 mph with gusts of 20 mph out of the E. The forecast area received 1 inch of new snow in the last 24 hours. There will be light snow this morning and then it will clear up this afternoon.
Overall the snowpack has settled and we are now in spring conditions. The avalanche problems are due to solar radiation and rising temperatures throughout the day (Diurnal Fluctuations). The way to manage these types of problems is to move from a sunny aspect to a shadier one throughout the day.
Dudley and I toured in the Rattlesnake yesterday. The main avalanche problem we observed was loose wet avalanches in the afternoon on sun exposed slopes. The second avalanche problem is cornice fall. Ed was in the southern Bitterroot and made mention of the rising temperatures in the afternoon and how large the cornices are. Cornices break father back than expected, give them space. This video shows the layers we will be concerned with in the next storm cycle on Sunday. Weather and Avalanche Outlook
There is a strong system predicted to enter the area early Sunday. This system is predicted to bring strong winds and 2 to 5 inches of snow by Sunday evening. The new load and strong winds will increase the avalanche danger. The snow level will decrease rapidly Sunday afternoon. The two problems to ask will be how the new snow bonds to the old snow surfaces(rime crust, surface hoar, and melt freeze crust). The second question will be are the facets reactive that are above the melt freeze crust from President’s Day weekend.
Ski and ride safe. Logan will issue the next advisory on Tuesday.
The current avalanche danger is MODERATE above 7,000ft and on wind loaded terrain. Human triggered avalanches are possible in specific areas. The avalanche danger at all other locations is LOW. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Tuesday, March 8th, 2016. Weather and Snowpack
Winter is making a subtle return to West Central Montana and has brought a trace to 3 inches of snow over night. Currently ridge top winds are light and gusting to the low teens from the W-WNW at Point Six and Deer Mountain. As of 5am this morning mountain temperatures are ranging from 22-30 degrees and light snow is expected through the early morning hours today.
Windslabs are the primary avalanche concern today. Windslabs are small and stubborn but are still lurking and warrant close attention. Windslabs are primarily located in terrain above 7,000ft. Carefully assess any terrain above 7,000ft that appears to be wind affected to determine if a windslab is present and reactive. Of particular concern are areas that are lightly wind affected and harboring persistent weak layers.
Persistent grains that are adjacent to the uppermost melt freeze crust (presidents day M/F crust) continue to be intermittently reactive. Areas that have a thin layer of soft wind load or the facets are nearer to the surface continue to occasionally be reactive in propagation tests (ECTP 12 pic). Avoid areas where facets are adjacent to the crust and close to the snow surface as well as areas that have a small soft windslab sitting on the melt freeze crust facets. The only way to know if these conditions exists is to dig pits, so carefully evaluate the snow and perform stability tests.
Lastly with crust consistently forming on the surface and light new snow over night the new surface snow will be susceptible to loose snow avalanches on terrain steeper than 35 degrees. Carefully evaluate the consequences of getting caught by even a small slide and avoid terrain traps. Avalanche and Weather Outlook
Light snow is expected to continue through the morning today and will be tapering off later in the afternoon. The next series of snow showers is expected to move in early Wednesday, but snow totals will be unremarkable. More snow is expected as the week progresses but snow levels look to climb later in the week. No major changes are expected to occur in the next couple of days and the avalanche danger will remain the same.
Travis will issue the next avalanche advisory on Thursday.
The current avalanche danger is Moderate in the west central Montana backcountry. Human triggered avalanches are possible. Heightened avalanche conditions exist in isolated terrain. Evaluate snow and terrain carefully and identify features of concern.
Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for March 10, 2016. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Mountain temperatures range from 28 F to 37 F in the region. Winds are 14 mph with gusts of 20 mph out of the SSE in the Bitterroot and Point Six in the northern part of the advisory area is 8 mph with gusts of 21 mph out of the SSE. The forecast area received 1 to 3 inches of new snow in the last 24 hours. The SWE totals are .2 to .8.
Tim and I toured in the Rattlesnake yesterday. The main avalanche problem is dry loose avalanches on steep(>35 degrees) slopes above 7000 ft. In the lower elevations these will be loose wet releases. These are not a problem unless they knock you off your feet and take you into a terrain trap (tree, gully or cliff).
The second avalanche problem is a persistent slab. The weak layer is a layer of facets that sits above a melt freeze crust. This layer is 30 cm to 60 cm deep in the snowpack. The facets propagate in very isolated pockets on southernly exposed slopes. The only way to find this layer is to dig a pit and see if it is reactive in your tests. There are other crusts in the upper snowpack with facets above them that could become more reactive with the additional loading of new snow. It is always prudent to dig a pit before committing to a slope.
The last problem is small wind slabs are forming with the increasing winds. These slabs will be located on leeward slopes in the higher elevations(>7000 ft).
Weather and Avalanche Outlook
The system that is currently in the area is expected to continue today with a cold front entering the area tonight. This system is expected to have snow levels increase from 5000 ft to 6000 ft through the day. The cold front will bring snow levels back down to 3500 ft. Winds are predicted to increase today to 50 mph on ridge tops. With these conditions the avalanche hazard will increase. The main problems will be windslabs and new loading on old snow surfaces. With the addition of new heavy wet snow the facets in the snowpack could become more reactive.
Ski and ride safe. Logan will issue the next advisory on Saturday.
The current avalanche danger is MODERATE for the west central Montana backcountry. Mild temperatures and a load of new dense snow will make human triggered avalanches possible on specific terrain features.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Saturday, March 12, 2016. This danger rating does not apply to operating ski areas, expires at midnighttonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Precipitation over night was limited to 1-2 inches of snow in the southern Bitterroots. However since mid-week the advisory area received about an inch of SWE, providing a stout load mainly to the southern portion of the region. Mountain temperatures this morning are above freezing and the winds are currently 5 mph gusting to 17 mph from the SSE at Point 6, and 15 mph gusting to 21 mph from the S at Deer Mountain further south.
Nick and Geoff toured near Lost Trail Pass on Thursday and found a new load of warm wet snow sitting on colder lower density snow. Travis and I were in the rattlesnake Yesterday and also found a modest new load of warm snow along with mild temperatures and significant solar radiation. The primary concern today will be loose wet slides in steep or heavily solar affected terrain. Avoid terrain traps and plan routes accordingly to avoid slopes that are receiving abundant solar radiation and warming.
Persistent slabs continue to be the secondary avalanche concern as we found layers of facets in the Rattlesnake and at Lost Trail that were failing readily in compression test but were failing to propagate. Although the persistent slabs are not propagating a new load of heavy snow may bring us to the tipping point that results in slab releases of the persistent weak layers. Dig pits on representative slopes to determine if persistent weak layers are present and if they may be reactive and reevaluate slopes as the load changes throughout the day.
Lastly strong winds continue to be the norm for the advisory area, windslabs are small but widespread and can best be described as “pockety”. Carefully evaluate terrain for signs of wind deposition and be leery of cornices as well. The varied but strong winds have made some double cornices and pockets of wind slabs can be found on nearly all aspects. Weather and Avalanche Outlook
The wet pattern that is currently moving through the area is expected to continue brining light snow and rain today with a cold front entering the area late Sunday. Current conditions will leave snow lines high until the passage of the cold front later this weekend. Avalanche hazard will remain the same but keep in mind that avalanche activity will peak today in the afternoon with high solar radiation and warm temperatures.
The next advisory will be issued on Tuesday, if you get out please share your observations on our public observations page.
The current avalanche danger is MODERATE for the west central Montana backcountry. With a new load of snow yesterday and today, human triggered avalanches are possible in specific areas. Carefully evaluate how the new load is affecting a slope when choosing areas to recreate.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Tuesday, March 15th, 2016. This danger rating does not apply to operating ski areas, expires at midnighttonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Winter has made a welcome return to west central Montana. The northern half of the advisory area received the lions share of snow since sunday night. Snow totals in the northern reaches are around 6-12 inches bring around an inch of SWE since Sunday night. In the southern half of the region snow totals were 2-5 inches. Strong winds were also seen yesterday afternoon peaking with gusts in the 40’s out of the West. Winds are currently 16mph gusting to 33mph from the W at Point 6 and are more moderate further south at Deer Mountain where current wind speeds are 7mph gusting to 13mph from the SSW.
The primary avalanche concern today will be windslabs above 7,000 ft. With strong winds yesterday and new snow for transport lee terrain will have windslab formation and will be the most likely place to trigger slab avalanches today. Avoid traveling on or under terrain that has been recently wind loaded.
The new snow was a welcome change and Travis and Dudley were in the Rattlesnake yesterday. They found 6+ inches that was falling on yet another crust. The new snow on the crust will result in loose snow avalanches on terrain steeper than 35 degrees. There are 3 distinct crust in the upper portion of the snowpack. The rime crust and the presidents day melt-freeze crust are of most concern, they continue to give clean shears in compression tests but don’t propagate (video). Dig pits and look for areas where the crust is reactive and has facets near by. Any of the crusts may start to propagate with the new load so take the time to look for them and determine if they are reactive. Weather and Avalanche Outlook
Old man winter is going to linger for a few days bringing waves of snow showers to the area that may have intense snowfall during some periods. The cold wet pattern will continue through mid-week, with today being the best chance for significant snow accumulations. An additional 2-6 inches are expected today while the next few snow events will have more modest snow accumulation. Conservative decision making would be wise as the inches start to stack up, avalanche danger will increase as the snowfall does. Stay aware of conditions as they change throughout the day.
Ski and ride safe, Travis will issue the next advisory on Thursday.
The current avalanche danger is MODERATE in the west central Montana backcountry. Human triggered avalanches are possible. Heightened avalanche conditions exist in isolated terrain. Evaluate snow and terrain carefully and identify features of concern.
Good morning, Happy St. Patrick’s Day, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for March 17, 2016. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Mountain temperatures range from 14 F to 23 F in the region. Winds are 08 mph with gusts of 12 mph out of the WSW in the Bitterroot and Point Six in the northern part of the advisory area is 11 mph with gusts of 14 mph out of the NW. The forecast area received 3 to 5 inches of new snow overnight. In the last 72 hours the region has received around 14 to 16 inches. Winter has returned.
Steve and I took sleds to the Lolo Pass area yesterday. The primary avalanche concern today are wind slabs. These slabs will be located on leeward terrain. There has been a lot of new snow with wind, look for scoured snow or hollow, drumlike sounding snow. These wind slabs could be triggered by a rider.
The second avalanche problem is dry loose avalanches. There is a lot of new snow, these loose dry avalanches will be found on steep slopes (>35 degrees), they should not be a problem unless they carry you into a terrain trap (tree, cliff, or gully). If the sun comes out expect these to turn to loose wet avalanches on sun exposed slopes.
There are some layers in the top meter of the snowpack to look at. There are several crusts with facets on top or below the crust. These layers have become less reactive in the last month but it is always prudent to dig a pit before recreating on a steep slope. Weather and Avalanche Outlook.
A cold front will bring snow showers to the area today. The forecast calls for 3-6 inches of new snow today with gusty winds. High pressure will start to build in the area on Friday. I would expect the avalanche danger to remain the same with these conditions.
Ski and ride safe. Have a great St. Patricks Powder Day. I will issue the next advisory on Saturday.
The current avalanche danger is MODERATE in the west central Montana backcountry. Human triggered avalanches are possible. Heightened avalanche conditions exist in isolated terrain. Evaluate snow and terrain carefully and identify features of concern.
Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for March 19, 2016. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Mountain temperatures range from 11 F to 21 F in the region. Winds are 13 mph with gusts of 16 mph out of the SE in the Bitterroot and Point Six in the northern part of the advisory area is 06 mph with gusts of 11 mph out of the S. The forecast area received no new snow overnight.
Steve and I toured in the Rattlesnake yesterday. Ed was in the southern Bitterroot. We observed small natural loose dry avalanches on steep terrain(>40 degrees). The main avalanche problem today is loose dry avalanches turing to loose wet avalanches on sun exposed slopes in the afternoon. These loose avalanches can entrain a lot of snow and could knock you off your feet so, be aware of terrain traps on the slopes you are recreating on.
The second avalanche problem are wind slabs. These are located on leeward terrain. Look for scoured snow and hollow sounding snow to identify these slabs.
There are persistent weak layers in the top meter of snow (crusts with facets above and below). Dig a pit before committing to any steep slope to see if any of these layers are reactive. Weather and Avalanche Outlook
For the weekend we will be under a ridge of high pressure. This will cause temperatures to above normal. With temperatures rising in the day and throughout the weekend, we make the shift back to spring conditions. If the slope you are recreating on starts to feel saturated or wet it is time to move to a different slope. The avalanche danger will remain the same with these conditions.
Ski and ride safe. Logan will issue the next advisory on Tuesday.
The current avalanche danger is LOW for the west central Montana backcountry. Human triggered avalanches are still possible in isolated terrain and conditions may change rapidly throughout the day as a strong system of snow moves into the area. Carefully assess how the new snow is affecting the snowpack and don’t be surprised if the danger climbs to moderate by the afternoon.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Tuesday, March 22nd, 2016. This danger rating does not apply to operating ski areas, expires at midnighttonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Snow is slowly moving into the area and a trace to 2 inches of snow has been recorded so far this morning. Currently mountain temperatures are hovering around freezing and winds are light and gusting to the teens from the ESE- S as the storm pushes into the region. Snow is expected to continue and intensify through midday and snow levels will drop throughout the morning.
Tim and I rode from Lolo Pass to Granite Pass yesterday and found wet saturated snow. The snowpack is moving towards being isothermal and mostly wet rounded and polycrystals were seen yesterday. We found loose wet slides to be the primary concern yesterday and loose snow will continue to be the primary concern today in the form of loose wet in areas that are receiving still relatively warm or receiving significant solar radiation and loose dry in areas that are accumulating new cold snow.
The new snow should bond fairly well to the old warm snow surface but as more snow falls keep an eye on how the storm slab bonds. If snow totals are high enough and there is a significant new load of SWE give the snow time to adjust to the new load. With temperatures hovering right around freezing as the snow is starting to fall areas may have had the snow surface freeze and now the new storm snow will be accumulating on a good bed surface. Storm slabs will not be apparent first thing this morning but will potentially develop later in the day so plan accordingly when choosing when and where to recreate today. Weather and Avalanche Outlook
Currently light snow is falling in the mountains of west central Montana and more is expected through noon. Above 6,000ft about 6+ inches is predicted in the forecast and snow totals will be greater towards the northern half of the advisory area. Winds will likely increase and shift to the west as the system moves into the region. The new snow will increase the avalanche danger in areas where enough snow has fallen to overload the interface or other weak layers in the snow pack.
Ski and ride safe, the next advisory will be issued on Thursday.
The current avalanche danger is LOW for the west central Montana backcountry. Small human triggered avalanches are possible in isolated or extreme terrain. Conditions will change rapidly today and can easily climb to moderate as more load is added to the snowpack. Stay aware of changing conditions and adjust plans accordingly.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Thursday, March 24th, 2016. This danger rating does not apply to operating ski areas, expires at midnighttonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Light snow continues to fall across the region and an additional 1-2 inches of snow was seen overnight, except in the northern tip of the advisory area where and additional 5 inches of snow has accumulated and .8 inches of SWE has been added to the snowpack. Winds tapered off overnight and are currently 18 gusting to 26 mph from the south at Deer Mountain and are expected to climb to 50+ mph today. Currently mountain temperatures are ranging from 26-32 degrees fahrenheit.
The primary avalanche concern today will be loose dry avalanches on terrain steeper than 35 degrees. Tim and I were in the Rattlesnake yesterday and found 2-3 inches of dry snow sitting on a crust. The new loose surface snow readily moves on steeper terrain and will be particularly problematic in areas that have terrain traps that increase the consequences of getting knocked off your feet or going for a ride in the loose snow. The North Fork Jocko snotel sight is reporting 5 inches of snow and .8 inches of SWE this morning and may have formed a small soft slab but with light winds and cool temperatures will more likely behave as a larger loose snow avalanche that has more snow to entrain upping the consequences further.
Winds dropped off overnight but are already slowly climbing back up this morning. With strong gusting winds yesterday and today coupled with new loose snow for transport windslabs have the potential to be problematic as they continue to grow. Currently windslabs are small and isolated to specific lee terrain and are generally above about 7,500 feet. Carefully evaluate any slope before recreating to determine if it has a windload that has the potential to propagate and fail as a slab. Weather and Avalanche Outlook
Light snow is expected to continue and intensify throughout the day today and is predicted to continue through the end of the week. Winds are also expected to intensify over the next 24 hours to 50+ mph gusts. Avalanche danger will increase as snow and wind continue to impact the advisory area.
Ski and ride safe, the next advisory will be issued by Travis on Saturday.
The current avalanche danger is considerable in the west central Montana backcountry on steep(>35 degrees), wind loaded slopes above 7000 feet. Human triggered avalanches are likely on these slopes. On all other slopes the danger is a stout moderate. Today cautious decision making is essential and careful route finding is necessary.
Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for March 26, 2016. This danger rating does not apply to operating ski areas, expires at midnighttonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Mountain temperatures range from 14 F to 24 F in the region. Winds are 04 mph with gusts of 06 mph out of the SSW in the Bitterroot. At Point Six in the northern part of the advisory area winds are 06 mph with gusts of 09 mph out of the WSW. The forecast area received 10-18 inches in the last 48 hours. The Twin Lakes Snotel in the central Bitterroot and North Fork Jocko in the northern portion of the advisory area picked up the most snow.
Dudley and I toured in the Rattlesnake yesterday. Ed was at Gash Point on Thursday in the central Bitterroot. Winter has made a strong comeback above 6500 feet. The first avalanche problem are wind slabs. In the last 48 hours we have had strong winds accompanying new snow, this has created wind slabs on leeward terrain that are small to large in size depending on the snow totals in the area. These slabs were touchy to Dudley and I in the Rattlesnake.
The Second avalanche problem are storm slabs. These slabs are reactive to human triggers on steep slopes(>35 degrees). The slab sits on top of the last melt freeze crust and ranges in depth from 10 inches to 16 inches throughout the advisory area.
The third avalanche problem are loose dry avalanches. The new snow sits on the last melt freeze crust and has not bonded well to this crust. Where the new snow has not consolidated into a slab you will likely trigger a large loose dry avalanche. These sluffs were large yesterday in the Rattlesnake and at Gash point on Thursday. These loose dry avalanches have the potential if you are not paying attention to knock you down and take you into a terrain trap on steep slopes(>35 degrees).
The last avalanche problem is cornice failure. It is spring, the cornices are large and with the warm temperatures in the afternoon cornices are weakening. Give cornices respect by limiting the time below them and give them a wide berth on ridges. Cornices break farther back than expected.
The last two melt freeze crusts are the layers of concern in the snowpack. They have not propagated in any of our tests in the last couple of weeks, but should be evaluated. If I was recreating today, I would dig a pit a meter into the snow pack and see if any of these layers are reactive with the new loading. I would look for signs of wind loading, scoured snow surface, hollow sounding snow and I would avoid aspects that showed any of these. The storm slab will show itself by localized cracking and shooting cracks from the skis on your feet or machine. The sluffs will be identified by loose unconsolidated snow triggered from your mode of travel in the backcountry. Weather and Avalanche Outlook
Through Sunday we will have a high pressure system throughout the region. On Sunday a cold front is expected to push into the area and bring with it the ability to produce afternoon snow showers. It should leave the area by Monday night. These warmer conditions in our region will make it feel like spring in the high country until the cold front pushes in on Sunday. The avalanche danger will stay the same, but change the problem of loose dry to loose wet in the afternoons on sun exposed slopes.
Ski and ride safe. I will issue the next advisory on Tuesday.
The current avalanche danger is MODERATE in the west central Montana backcountry. Human triggered avalanches are possible. Heightened avalanche conditions exist in isolated terrain. Evaluate snow and terrain carefully and identify features of concern.
Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for March 29, 2016. This danger rating does not apply to operating ski areas, expires at midnighttonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
Mountain temperatures range from 19 F to 27 F in the region. Winds are 19 mph with gusts of 30 mph out of the NNE in the Bitterroot. At Point Six in the northern part of the advisory area winds are 21 mph with gusts of 44 mph out of the ENE. The advisory area received no new snow overnight. The region picked up 3 new inches of snow in the last 48 hours.
Tim and I took the sleds to the Lolo Pass area yesterday. The primary avalanche problem is loose dry avalanches on shaded aspects and loose wet avalanches on sun exposed aspects. Conditions can change quickly in the spring and are very elevation specific. It feels like winter on the high ridges and as you go down in elevation it feels like spring.
The second avalanche problem is the persistent slab that is failing on facets that sit on the last melt freeze crust. This layer propagated in our tests on shadier aspects yesterday. These facets are reactive on some slopes. The way to identify this layer is to dig a pit a meter into the snowpack and see if it is reactive in your tests before committing to a steep slope.
The final avalanche problem is cornice failure. The cornice are very large right now and with warming temperatures in the afternoon are weakening. Give them a wide berth. Weather and Avalanche Outlook
We will have moderate temperatures for the next couple of days with a possibility of picking up small amounts of snow. The region will experience high winds the next couple of days. The avalanche danger with these conditions should stay the same. Remember in the spring, conditions can change rapidly. With the strong winds there is new snow available for transport. I would look for leeward terrain to have wind slabs formed on it.
Ski and ride safe. Logan will issue the next advisory on Thursday.
The current avalanche danger is Moderate for the west central Montana backcountry. Small human triggered avalanches in specific areas and larger avalanches in isolated terrain are possible.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Thursday, March 31st, 2016. This danger rating does not apply to operating ski areas, expires at midnighttonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
A Canadian cold front is working its way into the region and will bring cooler temperatures and light snow before warming for the weekend. As of 5am this morning a trace to 2 inches of snow have been recorded in the advisory area. Winds at Point 6 are currently 18 gusting to 29 from the north and mountain temperatures are hovering just above freezing.
Tim and I were in the Rattlesnake yesterday and found favorable skiing conditions on shaded aspects with all other aspects developing a new surface crust. We also found the primary avalanche concern to be windslabs. The windslabs are small and thin but can be found on all aspects above 6,500ft as strong winds were seen out of the E for the last few days and prevailing winds were from the W prior to that. Carefully evaluate terrain for signs of wind effect to determine if windslabs are present and reactive.
The secondary avalanche concern will be loose snow avalanches, which will be fairly widespread on steep terrain (>35degres). The loose snow will be dry on shaded aspects and wet on solar affected aspects. Carefully assess the consequences of even a small slide and avoid terrain traps.
Lastly there is still a concern over persistent slabs. Earlier this week near Lolo facets above a crust were propagating on Eastern aspects and Tim and I found them on a SE aspect in the Rattlesnake yesterday. They were not propagating in the Rattlesnake but were producing nice Q1 sheers. The facets seem to be most prominent on solar affected aspects and will be reactive in isolated areas so dig and do stability tests to determine if they are present and readily propagating. Weather and Avalanche Outlook
As the Canadian cold front moves through the region sparse light snow will be seen periodically. Following the cold front temperatures will climb again and conditions look to be high and dry for the weekend. With no significant changes in the forecast, avalanche hazard will remain the same through today. As warm sunny weather sets in conditions may change rapidly leading into the weekend and wet slabs and cornice failures may become a concern.
Ski and ride safe, the next regularly scheduled advisory will be issued on Saturday.
The current avalanche danger is Moderate for the west central Montana backcountry. Spring skiing and riding conditions are in full effect, the danger will start as LOW this morning but will rapidly climb to MODERATE as the sun and warm temps start to affect the snow.
Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Saturday, April 2nd, 2016. This will be the last regularly scheduled advisory of the season, but an update will be posted for next weekend and additional updates may follow if conditions warrant. Remember this danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service. Weather and Snowpack
High pressure continues to build over west central Montana and conditions will be warm and dry again today. No new snow was seen overnight and winds are currently 25mph gusting to 30mph from the west at Point 6. Most mountain locations did not freeze overnight and temperatures are ranging from 28-33 degrees.
The primary avalanche concern today will be loose wet slides. Travis and Dudley were in the Rattlesnake yesterday and observed loose wet slides on all aspects and elevations. Loose snow activity will increase throughout the day as the sun warms the snow surface. If rollerballs or small point releases are observed on the aspects you are on, move to a more shaded aspect, and avoid terrain traps; loose wets slides can be fun to start or play with but they can be deadly. Keep in mind that there have been fatalities around the area that have resulted from small loose wet slides past, so don’t let your guard down.
The secondary avalanche concern will be persistent slabs. Facets siting above crusts continue to be concerning but are no longer propagating. The persistent slabs may also become active as wet slabs as the snow is trending towards isothermal. Dig pits and perform stability tests to determine if the facets are present and if they are reactive, and don’t be afraid to err on the side of caution especially as the snow gets wet later in the day.
Lastly, be wary of cornices. We have seen large cornices throughout the advisory area and without freezing overnight and warm sunny days its only a matter of time until they start dropping. Cornices have a really nasty habit of breaking back farther than expected and will be major hazards until the snow is gone. Weather and Avalanche Outlook
A weak disturbance will move through the area tonight but snowfall will be unremarkable and snow levels will be high. The high pressure is expected to be the dominant feature over the weekend. Avalanche conditions will climb throughout the day, stay aware of conditions as they change today.
Thanks for a wonderful season and stay safe out there. Steve will issue an update for next weekend.
Above normal temperatures will increase the avalanche danger this weekend.
At 5 am mountain temperatures are in the 40’s with 14 mph SW winds gusting to 25 mph at Point Six and SW winds at 9 gusts to 14 at Deer Point near Darby, MT. Mountain temperatures have remained above freezing for about 4 days now.
Good morning, this is Steve Karkanen with late season avalanche information from the West Central Montana Avalanche Center.
Springtime Snow Safety Considerations
Wet, loose snow avalanches can entrain enough snow to cause step down slab avalanches that tend to be more destructive and not survivable. Even small wet snow avalanches can be deadly. Skiers and snowmobilers have died in wet snow avalanches in western MT after getting caught in relatively shallow wet snow avalanches.
Wet slab avalanches are a troublesome beast so when mountain temperatures remain above freezing for a night or two, don’t trust anything steep and loaded.
Cornices are not only scaring looking, they also fail easily all by themselves when it warms up. A large cornice dropping onto a big slope can trigger large slab avalanches, wet or dry, this time of year. Steer clear of them, they have a nasty reputation for breaking further back than expected when they get this big.
Assess how well new storm snow bonds to the old snow surface. Many natural avalanches were observed after the last snowfall as soon as the sun hit the slope. Fresh wind slabs can be very sensitive during and for a few days after a storm.
Overall stability conditions are easily monitored by paying attention to the aspect and air temperature. Move to more shaded northerly terrain as the temperature warms above freezing. Avoid being on or under open steep terrain when you see pinwheels or small point release avalanches peeling off steeper terrain. When you start punching through to your boot tops move to cooler/shaded areas where the snow is more stable.
When the ski areas are closed, the in-bounds terrain is backcountry terrain and you must plan accordingly. If you are unsure about a resort’s uphill policy, or where to access public land from a resort, the time-honored Montana tradition is to ask the landowner.
We will continue to post public observations as we receive them and will post updated information if conditions change dramatically.
This will be our last information statement for this season but we will continue to monitor and post any public observations as we receive them. If you get out and see something worth passing along, please send us an email or use the form available on our website at missoulaavalanche.org. The information provided might keep someone out of trouble.
Thanks for another great season and for all the support this year! We couldn’t do it without your financial help and it is deeply appreciated. A special thank you goes out to the dedicated board members of the West Central Montana Avalanche Foundation, our non-profit support organization.
</td></tr></tbody></table></td></tr><tr><td align="center" valign="top" style="border-collapse: collapse;"><table width="600" border="0" cellspacing="0" cellpadding="0"><tbody><tr><td valign="top" style="border-collapse: collapse; background-color: rgb(255, 255, 255);"><table width="100%" border="0" cellspacing="0" cellpadding="20"><tbody><tr><td valign="top" style="border-collapse: collapse;">
The current avalanche danger for the west central Montana backcountry is MODERATE. Natural avalanches are unlikely and human triggered avalanches are possible in specific areas. This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service.
