2018-19 "Post-Season Report" 4/23/19 West Central Montana avy conditions.

Scott

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The most current avalanche report is the very last post of this thread.

Current West Central Montana Avalanche Advisory
Posted: Oct 31, 2018 06:44 am
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Missoula Avalanche
Avalanche Special Update – Early Season Update – October 31, 2018

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Happy Halloween! This is Travis Craft with an early season snowpack update, on Wednesday, October 31, 2018.

We’d like to convey our sincere thanks to the volunteers, board members, sponsors and everyone who joined us at the 12th annual Pray For Snow Party! Our major fundraising event of the year was a success! The funds raised will help cover the expenses for the avalanche forecasts and education programs the region relies on. Again, thank you for your continued support.

In response to the growing number of folks recreating in the backcountry, we will be increasing our presence in the field and creating new ways to educate people about avalanche safety. Please take the time to fill out this survey and help us better serve our community.

Snotel sites are starting to accumulate snow. Winter is slowly taking over the higher elevations. It is time to think about avalanche awareness and preparing for backcountry recreation.

In the past, there have been several early season close calls and fatalities in Montana involving hunters, climbers and skiers. Hunters and Climbers: Please keep avalanche safety on your mind as you travel across steep, open terrain. Consider traveling with a partner and carrying rescue equipment. Skiers: If there is enough snow to ride, there is enough snow to slide!

If you see any of these clues signaling dangerous snow conditions, avoid being on or under open slopes steeper than 30 degrees:

Recent avalanche activity
Cracking or collapsing snowpack
Heavy snowfall
High winds
Rapid increase in temperature
If you spend time in the mountains during the winter, chances are you will encounter avalanche terrain. Understanding the terrain, weather and snowpack will significantly assist in making good decisions. To help you, we are offering several basic and advanced avalanche awareness classes this winter. This includes opportunities for private organizations who may be interested in a range of programs from introductory lectures to classes with a field component.

While out recreating, any information you can provide the WCMAC is appreciated and helps us inform the rest of the community about avalanche safety conditions. Please send a quick email to info@missoulaavalanche.org or complete the easy to use public observation form.

We will update the advisory as the weather dictates and plan to begin issuing regular avalanche advisories with a danger rating in mid-December.



The post Avalanche Special Update – Early Season Update – October 31, 2018 appeared first on Missoula Avalanche.



This information is the sole responsibility of the Forest Service and does not apply to operating ski areas. The avalanche danger rating expires at midnight tonight but you can use the information we provide to help you make more informed decisions regarding travel in avalanche terrain for the next few days.

Our advisory area includes the Bitterroot Mountains from Lost Trail Pass North to Hoodoo Pass, the Rattlesnake Mountains and the Southern Swan and Mission Mountains near Seeley Lake. Avalanche information for the Lookout Pass/St. Regis Basin is available from the Idaho Panhandle Avalanche Center.
 
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Scott

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Current West Central Montana Avalanche Advisory
Posted: Oct 31, 2018 08:30 am
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Missoula Avalanche
Avalanche Special Update – Early Season Update – October 31, 2018

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Happy Halloween! This is Travis Craft with an early season snowpack update, on Wednesday, October 31, 2018.

We’d like to convey our sincere thanks to the volunteers, board members, sponsors and everyone who joined us at the 12th annual Pray For Snow Party! Our major fundraising event of the year was a success! The funds raised will help cover the expenses for the avalanche forecasts and education programs the region relies on. Again, thank you for your continued support.

In response to the growing number of folks recreating in the backcountry, we will be increasing our presence in the field and creating new ways to educate people about avalanche safety. Please take the time to fill out this survey and help us better serve our community.

Snotel sites are starting to accumulate snow. Winter is slowly taking over the higher elevations. It is time to think about avalanche awareness and preparing for backcountry recreation.

In the past, there have been several early season close calls and fatalities in Montana involving hunters, climbers and skiers. Hunters and Climbers: Please keep avalanche safety on your mind as you travel across steep, open terrain. Consider traveling with a partner and carrying rescue equipment. Skiers: If there is enough snow to ride, there is enough snow to slide!

If you see any of these clues signaling dangerous snow conditions, avoid being on or under open slopes steeper than 30 degrees:

Recent avalanche activity
Cracking or collapsing snowpack
Heavy snowfall
High winds
Rapid increase in temperature
If you spend time in the mountains during the winter, chances are you will encounter avalanche terrain. Understanding the terrain, weather and snowpack will significantly assist in making good decisions. To help you, we are offering several basic and advanced avalanche awareness classes this winter. This includes opportunities for private organizations who may be interested in a range of programs from introductory lectures to classes with a field component.

While out recreating, any information you can provide the WCMAC is appreciated and helps us inform the rest of the community about avalanche safety conditions. Please send a quick email to info@missoulaavalanche.org or complete the easy to use public observation form.

We will update the advisory as the weather dictates and plan to begin issuing regular avalanche advisories with a danger rating in mid-December.



The post Avalanche Special Update – Early Season Update – October 31, 2018 appeared first on Missoula Avalanche.



This information is the sole responsibility of the Forest Service and does not apply to operating ski areas. The avalanche danger rating expires at midnight tonight but you can use the information we provide to help you make more informed decisions regarding travel in avalanche terrain for the next few days.

Our advisory area includes the Bitterroot Mountains from Lost Trail Pass North to Hoodoo Pass, the Rattlesnake Mountains and the Southern Swan and Mission Mountains near Seeley Lake. Avalanche information for the Lookout Pass/St. Regis Basin is available from the Idaho Panhandle Avalanche Center.
 

Scott

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Current West Central Montana Avalanche Advisory
Posted: Nov 10, 2018 06:16 am
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Missoula Avalanche
Avalanche Special Update – Early Season Conditions – November 10, 2018

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This is Travis Craft with an early season snowpack update, on Saturday, November 09, 2018.

The primary concern at high elevations are shallow wind slabs. The second concern will be new snow instabilities this weekend. Beware of thin snow coverage and buried obstacles to amplify the consequences of an avalanche. The snowpack is generally too shallow on most mid and lower elevation terrain for avalanche concerns.

In the past, there have been several early season close calls and fatalities in Montana involving hunters, climbers and skiers. Hunters and Climbers: Please keep avalanche safety on your mind as you travel across steep, open terrain. Consider traveling with a partner and carrying rescue equipment. Skiers: If there is enough snow to ride, there is enough snow to slide!

If you see any of these clues signaling dangerous snow conditions, avoid being on or under open slopes steeper than 30 degrees:

Recent avalanche activity
Cracking or collapsing snowpack
Heavy snowfall
High winds
Rapid increase in temperature
If you spend time in the mountains during the winter, chances are you will encounter avalanche terrain. Understanding the terrain, weather and snowpack will significantly assist in making good decisions. To help you, we are offering several basic and advanced avalanche awareness classes this winter. This includes opportunities for private organizations who may be interested in a range of programs from introductory lectures to classes with a field component.

While out recreating, any information you can provide the WCMAC is appreciated and helps us inform the rest of the community about avalanche safety conditions. Please send a quick email to info@missoulaavalanche.org or complete the easy to use public observation form.

In response to the growing number of folks recreating in the backcountry, we will be increasing our presence in the field and creating new ways to educate people about avalanche safety. Please take the time to fill out this survey and help us better serve our community.

We will update the advisory as the weather dictates and plan to begin issuing regular avalanche advisories with a danger rating in mid-December.

The post Avalanche Special Update – Early Season Conditions – November 10, 2018 appeared first on Missoula Avalanche.



This information is the sole responsibility of the Forest Service and does not apply to operating ski areas. The avalanche danger rating expires at midnight tonight but you can use the information we provide to help you make more informed decisions regarding travel in avalanche terrain for the next few days.

Our advisory area includes the Bitterroot Mountains from Lost Trail Pass North to Hoodoo Pass, the Rattlesnake Mountains and the Southern Swan and Mission Mountains near Seeley Lake. Avalanche information for the Lookout Pass/St. Regis Basin is available from the Idaho Panhandle Avalanche Center.
 

Scott

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Current West Central Montana Avalanche Advisory
Posted: Nov 21, 2018 06:25 am
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Missoula Avalanche
Avalanche Special Update – Forecast of Heavy Snow – November 21, 2018

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Good morning this is Logan King with an early season update to the weather and snowpack conditions for November 21st, 2018.

The pattern of seasonable temperatures and clear skies is drawing to a close over the next few days. The National Weather Service is predicting heavy snow to move into the region sometime Thursday with rain in the valleys and wet heavy snow above 5000ft. West Central Montana looks to pick up about 3-6″ of snow with the start of the system potentially bringing up to a half inch of snow water equivalent (SWE). Friday and into Saturday brings the potential of 6-12″ of snow with an additional 0.5-0.75″ of SWE along with snow to the valley floor. The National Weather Service has stated a moderate to high confidence level with the forecast.

So what does this mean? The temperatures have been cool enough for the snow to stick since early November at most locations. The snow is faceting and loosing strength at some locations while going through a freeze-thaw cycle at others creating a surface crust. This new load will stress the snowpack in areas where the snow is weak and will also have a difficult time bonding to surface crusts. In either case expect to see the avalanche danger climbing through the weekend.

If you plan to take advantage of some time off this week and the early season snow over the long Holiday weekend be aware of the significant changes and stress the snowpack will likely be under. Keep and eye out for indicators of avalanche potential like:

Recent avalanche activity
Cracking or collapsing of the snow
Heavy snowfall rates and totals
High winds
Rapid changes in temperature
It is easy for bad habits to creep into our lives this time of year, so if you are out in avalanche country stay diligent and follow your protocols to stay safe and safely assess the avalanche hazards.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us, especially this time of year as data is sparse, conditions are variable and rapidly changing. If you haven’t had a chance yet please take a minute to fill out a quick survey and sign a petition to help improve the advisories and education program.

We will update the advisory as the weather dictates and plan to begin issuing regular avalanche advisories with a danger rating sometime in December.

The post Avalanche Special Update – Forecast of Heavy Snow – November 21, 2018 appeared first on Missoula Avalanche.
 

Scott

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Missoula Avalanche
Avalanche Special Update – Heavy New Snow – November 28, 2018

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Good morning this is Logan King with an early season update for November 28th, 2018.

The atmospheric river that has been impacting the region for the last few days is nearing its end. The new snow has significantly changed the look of our snowpack. The new snow is much warmer and denser than the cold dry snow that was already on the ground and has increased instability across the region. The heavy new load is stressing the snowpack and will take a few days to bond to the old snow surface. While touring near Lolo Pass yesterday we found the new load was resulting in shooting cracks and some localized collapses. At higher elevations expect the old snow to be weak and faceted and reactive under the new load.

If you are out in the backcountry carefully evaluate conditions before traveling in avalanche terrain. Remember that the shallow snow will increase the risk of trauma if caught in a slide as more rocks, stumps, and down trees will be exposed in the slide path. Don’t ruin your season with a poor decision, remember that there is still plenty of the winter ahead of us.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us, especially this time of year as data is sparse, conditions are variable and rapidly changing. If you haven’t had a chance yet please take a minute to fill out a quick survey and sign a petition to help improve the advisories and education program.

We will update the advisory as the weather dictates and plan to begin issuing regular avalanche advisories with a danger rating in early December.

The post Avalanche Special Update – Heavy New Snow – November 28, 2018 appeared first on Missoula Avalanche.
 

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Current West Central Montana Avalanche Advisory
Posted: Dec 04, 2018 06:42 am
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Missoula Avalanche
Avalanche Advisory for December 4, 2018

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The current avalanche danger is LOW in the west central Montana backcountry. Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for December 04, 2018. 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 8 F to 14 F in the region. In the Bitterroot winds are 5 mph with gusts of 8 mph out of the SSW. In the northern part of the advisory area, winds are reading 21 mph with gusts of 27 mph out of the West. The forecast area received 0 to 1 inch of new snow in the last 24 hours.

The forecast area has a relatively shallow snowpack ranging from 2 to 3 feet of snow. The upper elevations have the most snow and where you may encounter isolated avalanche problems.

The primary problem is wind slabs. Look for small wind slabs on leeward terrain. Look for snowdrifts and smooth, rounded deposits of snow on ridgelines. Avoid wind-drifted snow in steep terrain.

The second problem is persistent slabs. There is a crust with weak snow above it about 2 feet from the ground. This layer is one to keep in mind as we continue to get more snow in the upcoming week. Dig a pit to see if this layer is reactive. Dig your pit all the way to the ground to find this layer.

Overall we have safe avalanche conditions. Look out for stumps and rocks that are thinly covered by snow that could lead to injury. Remember that the shallow snow will increase the risk of trauma if caught in a slide as more rocks, stumps, and down trees will be exposed in the slide path. Use normal caution, continue to keep your guard up and look for any signs of snow instability. Evaluate snow and weather conditions as you travel.

page8image3723207840Avalanche and Weather Outlook
This week calls for very little change in the weather. We will have cold temperatures and little chance for precipitation. This means little will change with the avalanche danger.
If you are out in the backcountry, please send us your observations, these are very helpful in producing the advisory.

Join us tonight at Big Sky Brewing for an Avalanche Awareness night. Click on the link for more details.

I will issue the next forecast on Thursday.

Ski and ride safe.

The post Avalanche Advisory for December 4, 2018 appeared first on Missoula Avalanche.
 

Scott

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Current West Central Montana Avalanche Advisory
Posted: Dec 06, 2018 06:25 am
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Missoula Avalanche
Avalanche Advisory for December 6, 2018

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The current avalanche danger is LOW in the west central Montana backcountry. Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for December 06, 2018. 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 -6 F to 6 F in the region. In the Bitterroot winds are 10 mph with gusts of 14 mph out of the SSE. In the northern part of the advisory area, winds are reading 13 mph with gusts of 15 mph out of the WSW. The forecast area received 0 to 1 inch of new snow in the last 24 hours.

The forecast area has a relatively shallow snowpack ranging from 2 to 3 feet of snow. The upper elevations have the most snow and are where you may encounter isolated avalanche problems.

The primary concern is wind slabs. The forecast area received strong winds over the last couple of days drifting snow on ridgelines and leeward slopes. Look for smooth and rounded deposits of snow and avoid wind drifted snow in steep terrain. Early season obstacles can increase the consequences of an avalanche.

The second problem is persistent slabs. The cold temperatures have weakened the snowpack. There is a crust with weak snow above and below it throughout our forecast region. It has not been reactive yet in our tests. Dig a pit to the ground and identify the weak layers. These layers will become a concern with more snow in the upcoming week.

Overall we have safe avalanche conditions. Remember that the shallow snow will increase the risk of trauma if caught in a slide as more rocks, stumps, and down trees will be exposed in the slide path. Use normal caution, continue to keep your guard up and look for any signs of snow instability. Evaluate snow and weather conditions as you travel.

Avalanche and Weather Outlook

High pressure moves into the area with valley inversions today and through the weekend. The next chance for precipitin looks like Saturday. The high pressure will keep the avalanche danger the same. Click here for the backcountry forecast.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us, especially this time of year as data is sparse, conditions are variable and rapidly changing.

Join us tonight for an avalanche awareness night. Click here for details.

Logan will issue the next forecast on Saturday, December 08, 2018.

Ski and ride safe.

The post Avalanche Advisory for December 6, 2018 appeared first on Missoula Avalanche.
 

Scott

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Current West Central Montana Avalanche Advisory
Posted: Dec 08, 2018 06:17 am
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Avalanche Advisory for December 8, 2018

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The current avalanche danger is LOW across the West Central Montana backcountry. Generally safe avalanche conditions can be found, but careful evaluation of terrain and conditions are still essential for safe travel. Watch for unstable snow on isolated terrain.

Good morning, this is Logan with the West Central Montana Avalanche Center’s avalanche advisory for Saturday December 08th, 2018. 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

As of 5 am this morning mountain temperatures range from the high teens to low twenties. Little snow has been seen for a prolonged period with the occasional dusting of snow. Ridge top winds at Point 6 this morning are at 12 mph gusting to 17 mph from the West.

Currently the primary avalanche concern is wind drifted snow that is creating thins shallow wind slabs. The wind slabs are small but can be serious if you are in the wrong place at the wrong time. Consider the consequences of avalanches before committing to avalanche terrain and follow you safe travel protocols.

The secondary concern are persistent weak layers. These layers are not currently reactive as they generally lack slabs to transfer the energy and propagate, but will be a nagging concern once snow returns to the region. Take note of where you are seeing more surface hoar growth and increased faceting as these will become the problem areas when snow returns.

Avalanche and Weather Outlook

Cold and dry looks to be the norm over the weekend as a high lingers around the region. Inversions have set up with slightly warmer temperatures and clear skies at upper elevations. According to the forecast the next chance for snow looks to be early next week with the potential for a more significant shift by midweek.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

The next advisory will be issued on Tuesday the 11th.

Ski and ride safe.

The post Avalanche Advisory for December 8, 2018 appeared first on Missoula Avalanche.
 

Scott

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Current West Central Montana Avalanche Advisory
Posted: Dec 11, 2018 06:34 am
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Missoula Avalanche
Avalanche Advisory for December 11, 2018

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The current avalanche danger is MODERATE in the west central Montana backcountry above 6000 feet on wind drifted slopes. All other slopes are LOW hazard today. Identify wind loaded slopes and avoid them in steep terrain.

Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for December 11, 2018. 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 18 F to 28 F in the region. In the Bitterroot winds are 6 mph with gusts of 9 mph out of the SSW. In the northern part of the advisory area, winds are reading 16 mph with gusts of 22 mph out of the West. The forecast area received 2 to 4 inches of new snow in the last 24 hours.

The primary avalanche concern today is wind drifted snow on steep terrain at higher elevations on ridglelines and leeward slopes.

The second avalanche problem is persistent slabs. The new snow is burying the surface hoar from the last high-pressure system. Look for these slabs to become more reactive as more snow accumulates. Use small test slopes with low consequences to see if these slabs are present. Dig a pit to the ground and perform an ECT to see if the buried surface hoar is on the slopes you want to recreate on(video).

There was a skier triggered slide on Murphy peak in the Rattlesnake on Sunday. No one was caught but, you can see by the pictures the consequences of getting caught and carried through steep terrain(Observations).

Avalanche and Weather Outlook

The next couple of days will be a test for our snowpack. With forecasted amounts of snow and high winds look for the avalanche danger to increase. Conditions can change quickly. Evaluate snow and weather conditions as you travel. Click here for the backcountry forecast.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

The post Avalanche Advisory for December 11, 2018 appeared first on Missoula Avalanche.
 

Scott

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Current West Central Montana Avalanche Advisory
Posted: Dec 13, 2018 06:51 am
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Missoula Avalanche
Avalanche Advisory for December 13, 2018

considerable danger
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The current avalanche danger for the West Central Montana backcountry is CONSIDERABLE on wind loaded terrain. Large human triggered avalanches are likely in specific locations. On all non-wind loaded terrain the avalanche danger is MODERATE. Careful snowpack evaluation and cautious route finding are essential to safely travel in the backcountry today.

Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for December 13th, 2018. 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

Over Tuesday night, winter made a return to the region and deposited between 8-14 inches of snow with some locations picking up an inch of SWE. The snow tapered off yesterday as the winds intensified. Since Tuesday afternoon the winds have calmed a bit and shifted from a westerly flow to a SSW-S and are currently 13 mph gusting to 20 mph at ridge tops. Over the past 24 hours area snotels have recorded an additional 1-3 inches of snow.

Yesterday we found the new snow had caused natural releases that were 8-10 inches deep over night, but conditions were already settling down by morning. Collapsing, whumphing and shooting cracks were localized to terrain where the wind was depositing snow. On a wind loaded slope we had and extended column test propagate at about 16″ deep on only 2 taps. This means that the primary avalanche concern today is wind drifted snow near ridglelines and on leeward slopes.

The secondary avalanche concern is storm slabs. The are some weaknesses within the new snow that will lead to reactive surface layers that will produce small loose snow sluffs. Loose snow avalanches are primarily problematic in steep exposed terrain where the consequences are higher. There is lots of loose snow that will easily be en-trained in small sluffs and can knock you off your feet or sled.

Finally, all of the new snow is sitting on a layer of surface hoar that formed over the last few weeks. The buried surface hoar is extremely weak but the new snow is lacking some of the slab properties needed to propagate and create large avalanches (except where wind affected). Below the buried surface hoar is a weak unconsolidated snowpack that is also suspect, but continues to be un-reactive in stability tests. Even though these weak layers are not overly reactive in tests, they will be hard to trust and will be a lingering problem for the foreseeable future.

Avalanche and Weather Outlook

A ridge of high pressure looks to set up for the next couple of days. Winds preceding the ridge will continue to load lee terrain but avalanche conditions will slowly settle as the snow adjusts and bonds over the next few days. The next few days should set up with above normal temperatures and gusty winds. The next loading event looks to impact the region sometime over the weekend (Forecast).

If you make it out into the backcountry feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful in producing the forecasts.

Ski and ride safe.

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Missoula Avalanche
Avalanche Advisory for December 15, 2018

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The current avalanche danger is CONSIDERABLE on wind loaded terrain across the West Central Montana backcountry. Large human triggered avalanches are likely in areas of wind deposition. On all non-wind loaded terrain the avalanche danger is MODERATE. Identification of wind loaded terrain is critical for backcountry travel today.

Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Saturday, December 15th, 2018. 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

Light snow showers are lingering in the region early this morning but are subsiding. Temperatures at 5 am are in the twenties and a prominent SW-SSW wind is impacting the advisory area with sustained winds in the teens and gust to the mid to upper twenties (mph). Snotels are reporting an additional 1-4 inches of snow with an that has added 0.1-0.4 inches SWE to the snowpack.

While touring yesterday we observed strong southerly winds that followed the westerlies from earlier this week. At upper elevations there was wind-loading on most aspects to varying extents. The locations with heavier wind loads had collapsing, whumphing and shooting cracks that clearly indicate a lack of stability. On a wind loaded slope we had and extended column test fail and propagate while isolating the column (profile).

The wind slab problem is further complicated by the weak snow structure. Most of the failures are occurring on a layer of buried layer of surface hoar. Along with the buried surface hoar there is a weak unconsolidated pack consisting primarily of facets. The weak granular snowpack lacks strength or stability and will be suspect until deeply buried or the snow starts to change forms and bond.

Carefully evaluate terrain to identify locations where the wind may have deposited snow. Look for rounded pillows of snow, cross loaded slopes, new cornices and sastrugi or anything else that may indicate which slopes are loaded. Remember the winds have been loading slopes unevenly and in uncharacteristic ways so take the time to actually assess if wind loading has occurred, don’t be surprised to find a pocket of wind-loaded snow somewhere that you have never seen before. If you hear whumphing or collapses and see shooting cracks, adjust you travel according to avoid areas that are suspect.

Avalanche and Weather Outlook

The forecast indicates light snow showers across West Central Montana this morning with the possibility of some stronger bands developing but snow should taper off by mid day today. Strong winds will impact the region this morning as a cold front passes through the region. Sunday looks to be dry and warm. The next round of snow looks to develop Tuesday or Wednesday (Forecast). The avalanche conditions look to remain the same for the next few days.

If you make it out into the backcountry feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful in producing the forecasts.

Ski and ride safe.

The post Avalanche Advisory for December 15, 2018 appeared first on Missoula Avalanche.
 

Scott

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Posted: Dec 18, 2018 06:36 am
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Avalanche Advisory for December 18, 2018

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The current avalanche danger is CONSIDERABLE in the west central Montana backcountry on all slopes. Dangerous avalanche conditions exist. Careful snowpack evaluation, cautious route-finding, and conservative decision-making are essential today. Look for the avalanche danger to increase throughout the day and go to HIGH with the predicted weather forecast.

Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for December 18, 2018. 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 31 F in the region. In the Bitterroot winds are 17 mph with gusts of 25 mph out of the SSE. In the northern part of the advisory area, winds are reading 11 mph with gusts of 17 mph out of the SE. The forecast area received 1 to 2 inches of new snow in the last 24 hours.

We have a very poor snowpack structure(video). There is buried surface hoar that is 12 to 24 inches from the surface. The other is a layer of facets or weak snow on the ground. These two layers are responsible for the near misses and the remote triggering of avalanches from this weekend. (Remote Trigger 01, Cornice Remote Trigger, Remote Trigger 02) See the public observations here. Thank you to everyone who has contributed public observations. These help the community and us the forecasters to be more informed and learn from them.

The primary avalanche problem is persistent slabs. Look for red flags such as whumpfing, collapsing and shooting cracks. Yesterday Logan and I would get off our machines and punch all the way to the ground; this is a sign of instability. Dig a pit to the ground and look for our buried layers and see how reactive they are in stability tests. Avoid traveling under runout zones and think of what terrain is above and below you. The layers in the snowpack are reactive to human triggers and are widespread throughout our forecast area. Travel and recreate on slopes less than 25 degrees.

The second avalanche problem is wind slabs. Look for snowdrifts and smooth, rounded deposits of snow on ridgelines. Avoid traveling on wind drifted terrain. Wind loaded terrain will have a higher likelihood of triggering an avalanche today.

Bottom line the snowpack is weak and can not be trusted. The new snow and wind today will increase the avalanche danger. Recreate on low angle terrain and pay close attention to changing weather conditions.

Avalanche and Weather Outlook

A warm, weak system will move over our area today. It will produce up to 6 inches of snow and have a fluctuating rain line around 5000 ft. See the forecast here. Look for the avalanche danger to increase with this weather event. Pay close attention to changing conditions.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

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Current West Central Montana Avalanche Advisory
Posted: Dec 19, 2018 06:05 am
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Avalanche Advisory for December 19, 2018

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The current avalanche danger is HIGH in the west central Montana backcountry on wind loaded slopes. Travel on wind loaded slopes or in runout zones is not recommended today. All other slopes are CONSIDERABLE.

Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for December 19, 2018. 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 12 F to 33 F in the region. In the Bitterroot winds are 10 mph with gusts of 15 out of the South. In the northern part of the advisory area, winds are reading 14 mph with gusts of 23 mph out of the North. The forecast area received 6 to 14 inches of new snow in the last 24 hours. The SWE totals range from .8 to 1.3 inches.

The primary concern today is wind slabs. The forecast area had high winds yesterday with a lot of snow available for transport. Look for snowdrifts and smooth, rounded deposits of snow on ridgelines. Avoid traveling on wind drifted terrain. Do not travel in runout zones below wind loaded terrain.

The second avalanche problem is persistent slabs. Look for red flags such as whumpfing, collapsing and shooting cracks. Dig a pit to the ground and look for our buried layers and see how reactive they are in stability tests. Avoid traveling under runout zones and think of what terrain is above and below you. The layers in the snowpack are reactive to human triggers and are widespread throughout our forecast area. Travel and recreate on slopes less than 25 degrees.

The third avalanche problem is storm slabs. The new snow will need time to bond with old snow surfaces and could potentially step down into buried weak layers causing a much larger avalanche.

Bottom line the snowpack is weak and can not be trusted with the additional loading of new snow and wind. Recreate on low angle terrain and pay close attention to changing weather conditions. Choose terrain that is simple (not connected to steeper slopes or in a runout zone) and low angle(>25 degrees).

Avalanche and Weather Outlook

The forecast area will have light accumulations of snow till late this afternoon. See the forecast here. Look for the avalanche danger to stay the same with these conditions.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

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Current West Central Montana Avalanche Advisory
Posted: Dec 20, 2018 06:14 am
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Avalanche Advisory for December 20, 2018

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For wind loaded terrain the avalanche danger remains HIGH across the West Central Montana backcountry. The danger on non-wind loaded terrain is CONSIDERABLE. Very dangerous avalanche conditions exist as large avalanches are possible in many areas. Cautious route finding is essential and travel in and around avalanche terrain is not recommended.

Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Thursday, December 20th, 2018. 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 this morning are in the twenties as of 4 a.m. Overnight a trace to an inch of snow fell at some locations but overall not much snow has fallen since mid-day yesterday. Winds are light out of the SSE-SE at about 8 mph and gusting to 10 mph.

Wind slabs are the primary avalanche concern today. Yesterday we remotely triggered a wind slab in the Rattlesnake (pic, video), and observed another skier triggered windslab while observers in the Bitterroot triggered a winds slab as well (pic). The big take away is wind slabs are wide spread, very sensitive to triggers, and are not something you want to be on, below, or near for that matter. If you are seeing signs of wind loading you can also expect to hear/see whumpfing, shooting cracks, collapsing and remote triggers; all of which should point you away from wind affected terrain.

Buried surface hoar continues to be reactive in stability tests and will make persistent slabs the secondary concern. The buried surface hoar is breaking down and is not as widespread as last week but is very reactive in stability test but can still be found on at many locations (video). Take the time to dig a pit to see if the persistent weak layers are present and reactive.

Avalanche and Weather Outlook

Snowfall should be minimal today with the next round of snow impacting the region tonight and into Friday (forecast). Strong winds are expected to usher in the next round of precipitation so expect to see strong winds develop through the day today. The lull today doesn’t appear to be long enough to let avalanche conditions settle down so they should remain the same leading into the next storm.

Join us tonight at Big Sky Brewing from 6-8 pm for Beers with Forecasters. Come have a beer and talk to your local forecasters about avalanche conditions, or ask a question you have been pondering all season. This is great opportunity to practice you rescue skills as well in the new beacon park at Big Sky Brewing.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

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Current West Central Montana Avalanche Advisory
Posted: Dec 22, 2018 06:34 am
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Avalanche Advisory for December 22, 2018

considerable danger
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The current avalanche danger is CONSIDERABLE for the West Central Montana backcountry. Human triggered avalanches are likely on specific terrain. Dangerous avalanche conditions exist and careful snowpack evaluation, cautious route-finding, and conservative decision making are critical for anyone traveling in the backcountry today.

Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Saturday, December 22nd, 2018. 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

On Friday morning an additional 3-9 inches of snow had accumulated across the region. Over the past 24 hours an additional 1-6 inches of snow fell and added up to 0.4 inches of SWE to the snowpack. Winds this morning are 9 mph gusting to 14 mph from the WSW. As of 4 am mountain temperatures range from 11 to 22 degrees Fahrenheit across the advisory area.

Winds slabs are one of the avalanche problems that you are likely to encounter today. They are not as touchy as they were earlier this week but are still problematic. Yesterday we observed localized collapsing and whumphing on wind loaded terrain. Wind slabs were not as reactive in stability tests as earlier this week but still need some time to settle. Avoid traveling on or under wind loaded terrain as wind slabs are likely to fail under the weight of a skier or sled especially in areas that also have buried surface hoar.

Persistent slabs are the other major concern today. In the northern half of the advisory area the surface hoar is breaking down and slowly gaining strength making it harder to identify at some locations but can easily be found while performing stability tests. Further south the snowpack remains weaker and has more prominent facets and surface hoar. Yesterday observers found the surface hoar to be very reactive under the new load of snow and reported widespread whumphing and collapsing. In areas with very weak snow structure any new load will have the potential to increase avalanche activity on the buried weak layers.

The take away is that there are still abundant red flag warnings of where avalanches are likely. Whumphing, shooting cracks, and collapsing continue to be a great indicator of suspect areas. Take a few minutes to dig a quick pit and make sure that there are no buried weak layers before committing to traveling in avalanche terrain. If you are seeing any red flags adjust your travel accordingly to avoid hazards. Remember that if you are in a suspect area it is LIKELY that you will trigger an avalanche.

Avalanche and Weather Outlook

Light and scattered snow flurries will continue today. Sunday will bring a significant change in the weather pattern and has the potential for a series of storms next week. Avalanche conditions will remain the same until the next round of precipitation starts to reload the snow structure.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

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Current West Central Montana Avalanche Advisory
Posted: Dec 24, 2018 05:28 am
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Avalanche Advisory for December 24, 2018

high danger
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The current avalanche danger is HIGH in the west central Montana backcountry on wind loaded slopes. Travel on wind loaded slopes or in runout zones is not recommended today. All other slopes are CONSIDERABLE.

Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for December 24, 2018. 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 20 F to 28 F in the region. In the Bitterroot winds are 3 mph with gusts of 4 out of the SE. In the northern part of the advisory area, winds are reading 2 mph with gusts of 6 mph out of the East. The forecast area received 6 to 14 inches of new snow in the last 24 hours. The SWE totals range from .4 to .9 inches.

The primary concern today is wind slabs. Look for snowdrifts and smooth, rounded deposits of snow on ridgelines. Avoid traveling on wind drifted terrain. Do not travel in runout zones below wind loaded terrain.

The second avalanche problem is persistent slabs. Look for red flags such as whumpfing, collapsing and shooting cracks. Dig a pit to the ground and look for our buried layers and see how reactive they are in stability tests. Avoid traveling under runout zones and think of what terrain is above and below you. The layers in the snowpack are reactive to human triggers and are widespread throughout our forecast area. Travel and recreate on slopes less than 25 degrees.

Bottom line: The snowpack needs time to adjust to the new snow. Travel and recreate on slopes less than 25 degrees. Do not travel in runout zones.



Avalanche and Weather Outlook

More snow throughout the day. See the forecast here.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

The post Avalanche Advisory for December 24, 2018 appeared first on Missoula Avalanche.
 

Scott

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Current West Central Montana Avalanche Advisory
Posted: Dec 24, 2018 05:28 am
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Missoula Avalanche
Avalanche Advisory for December 24, 2018

high danger
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The current avalanche danger is HIGH in the west central Montana backcountry on wind loaded slopes. Travel on wind loaded slopes or in runout zones is not recommended today. All other slopes are CONSIDERABLE.

Good morning, this is Travis Craft with the West Central Montana Avalanche Center’s avalanche advisory for December 24, 2018. 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 20 F to 28 F in the region. In the Bitterroot winds are 3 mph with gusts of 4 out of the SE. In the northern part of the advisory area, winds are reading 2 mph with gusts of 6 mph out of the East. The forecast area received 6 to 14 inches of new snow in the last 24 hours. The SWE totals range from .4 to .9 inches.

The primary concern today is wind slabs. Look for snowdrifts and smooth, rounded deposits of snow on ridgelines. Avoid traveling on wind drifted terrain. Do not travel in runout zones below wind loaded terrain.

The second avalanche problem is persistent slabs. Look for red flags such as whumpfing, collapsing and shooting cracks. Dig a pit to the ground and look for our buried layers and see how reactive they are in stability tests. Avoid traveling under runout zones and think of what terrain is above and below you. The layers in the snowpack are reactive to human triggers and are widespread throughout our forecast area. Travel and recreate on slopes less than 25 degrees.

Bottom line: The snowpack needs time to adjust to the new snow. Travel and recreate on slopes less than 25 degrees. Do not travel in runout zones.



Avalanche and Weather Outlook

More snow throughout the day. See the forecast here.

If you do make it out into the hills feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

The post Avalanche Advisory for December 24, 2018 appeared first on Missoula Avalanche.
 

Scott

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Current West Central Montana Avalanche Advisory
Posted: Dec 27, 2018 06:19 am
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Avalanche Advisory for December 27, 2018

considerable danger
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The current avalanche danger is CONSIDERABLE for the West Central Montana backcountry. Human triggered avalanches are likely in specific areas across the region. Safe travel in the backcountry will be achieved with keen hazard identification, cautious route-finding and careful snowpack evaluation.

Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Thursday, December 27th, 2018. 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

Light snowfall developed overnight and across the region 1-4 inches of snow has accumulated. Mountain temperatures were cold overnight keeping the snow drier with SWE values of 0.1-0.2 inches being recorded. As of this morning mountain temperatures are 14-22 degrees. Winds are light from the WSW at 2 mph gusting to 3 mph, however strong winds were reported over the weekend and holiday for parts of the advisory area.

The snowpack varies greatly across the region. As some areas gain strength others continue to have a weak structure that can not be trusted. The biggest problem that we continue to see are persistent weak layers. The buried surface hoar is still reactive when present and facets near the ground continue to cause problems in certain areas. At the southern end of our forecast area the snowpack is unconsolidated, and consists of sugary weak snow. While stronger snow can be found there is a mixed bag of snow structure for the norther half of the forecast area.

Persistent slabs are the main concern today. In areas where there is any sort of slab overlying a layer of buried surface hoar or facets continues to be reactive in stability tests and will be easily triggered if traveled on or near. Careful snowpack evaluation is needed to identify areas of heightened concern. The only way to know if facets or buried surface hoar is present on a slope is to dig a pit and perform stability tests.

Wind slabs continue to gain strength and are becoming less reactive but are ideally suited to fail in locations where facets or buried surface hoar are also present. The combination of very weak layers and firm wind slabs will create dangerous avalanche conditions. Verify that any location that has a slab doesn’t also have facets. The strong winds over the holiday have created some big wind slabs and will make for some touchy conditions across specific terrain.

The take away today is that conditions are complex and the consequences are high if you make a mistake. Don’t be lulled into a false sense of security. Take the time to do your due diligence; dig a pit and test the snowpack before travelling in avalanche terrain.



Avalanche and Weather Outlook

Light snow showers are expected to continue through the morning before a break in the weather. Avalanche conditions will not change much with light accumulations and dissipating snowfall. The next round of snow is setting up to arrive Friday night but there is uncertainty around snow levels and the snow has the potential to be warm and wet (forecast).

If you make it out into the mountains feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

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Current West Central Montana Avalanche Advisory
Posted: Dec 29, 2018 06:46 am
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Avalanche Advisory for December 29, 2018

moderate danger
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The avalanche danger for the West Central Montana backcountry is MODERATE. Large avalanches can be triggered in isolated locations and smaller avalanches are possible in specific terrain. Careful evaluation is needed to identify features of concern.

Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Saturday, December 29th, 2018. 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

As of 5:30 this morning mountain temperatures range from 14-24 degrees Fahrenheit. Winds remain light and are out of the South at 4 mph gusting to 9 mph. Wide spread snow showers overnight have deposited 2-6 inches of snow across the forecast area with SWE totals of 0.1-0.5 inches of water.

The avalanche danger has been trending “down” but that doesn’t necessarily mean its getting better. Many areas continue to gain strength, but there are a few locations where the opposite is occurring. Some locations have very weak snow and continue to be reactive to tests and the consequences of avalanches at these locations are trending up as more snow gets added to the snowpack, creating the potential for larger avalanches. The main problems continue to be persistent slabs and wind slabs.

Persistent slabs are the biggest problem right now. Yesterday in the southern Bitterroot we found depth hoar that resulted in whumphing, and collapsing, and propagated in stability tests on multiple aspects. There is also the buried layer of surface hoar that is breaking along with new surface hoar that is now getting buried and will be susceptible to triggers. The different faceted layers can be found on a variety of terrain across the forecast area, it is more prominent at some locations than other, so careful snowpack evaluation is very important to identify if layers of concern are present. Avoid likely trigger points like shallow or rocky areas and roll overs.

Wind slabs are the other major concern today. Areas that have seen wind loading can be identified by rounded pillows of snow and will be found on lee terrain or below cornices. Areas with weak snow and firm wind slabs will easily be triggered by snowmobiles or skiers today. Avoid traveling on or under wind loaded terrain especially in areas where persistent weak layers have also been identified.

Thursday’s advisory said to “not be lulled into a false sense of security” and that is even more true now. As many locations are gaining strength there are areas that avalanches are likely and have the potential to be big. Be aware of the consequences before traveling in avalanche terrain. Take the time to dig pits, use safe travel protocols and talk with your group as you travel through the backcountry.



Avalanche and Weather Outlook

Continued snow showers this morning will bring another few inches through the day today (forecast). Snowfall will pick up tonight and through Sunday with potential of widespread accumulating snow (Pic). With weak snow structure and a significant load being added over the weekend, avalanche danger will increase over the next few days. As the cold front moves through late today and into tomorrow strong winds (~50 mph) are expected (forecast).

If you get out into the mountains feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

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Current West Central Montana Avalanche Advisory
Posted: Dec 30, 2018 06:48 am
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Avalanche Advisory for December 30, 2018

considerable danger
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The current avalanche danger is CONSIDERABLE for the West Central Montana backcountry. A significant load of new snow and strong winds are creating dangerous avalanche conditions as human triggered avalanches are likely today.

Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Sunday, December 30th, 2018. 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

Since yesterday morning 4-10 inches of snow has fallen across the advisory area. The new snow has deposited 0.4-0.9 inches of SWE. Winds were out of the SW yesterday and around 5pm began gusting to 40-50 mph and were sustained in the 20’s. Winds shifted early this morning to the WNW and have settled but will ramp back up again and shift later today as the cold front moves through. Mountain temperatures are in the mid 20’s to low 30’s Fahrenheit this morning.

As expected, the current storm has notably increased the avalanche danger since yesterday. The new snow and strong winds are creating dangerous avalanche conditions. A lot of new snow is available for transport and is forming large dangerous Wind slabs. The new wind slabs will easily be triggered today and travel on or around wind loaded terrain is not advised.

The Persistent slabs are becoming increasingly reactive as well. The locations that have faceted snow and and buried surface hoar will be strained under the new load. Be cautious of locations with weak snow structure as they will need a day or two to adjust to the new load. With lots of new surface snow it will be possible to create small sluff avalanches that then act as triggers for the week layers deeper in the snowpack.

Conditions have drastically changed over the past 24 hours and will require an increased consideration of avalanche potential. Human triggered slides are likely, so use cautious route finding and make conservative decisions today as the snow will need some time to settle and adjust.

Avalanche and Weather Outlook

The mountains around West Central Montana remain under a Winter Storm Warning for continued snow and strong winds today. The new snow and strong winds will keep the avalanche danger trending upward. Look for the wind to shift to a more Northerly or Easterly flow late today as a cold front works into the region. The snow will begin to taper off as the week begins but cold temperatures are poised to set up for the beginning of the week (forecast).

If you get out into the mountains feel free to share what you see on our public observations page. They are not only helpful to your community but extremely helpful to us.

Ski and ride safe.

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