Avalanche danger should remain LOW for all elevations and aspects again today. Some small loose wet snow instabilities could still occur on some steep slopes today on any aspect where snow cover still exists. Sunny E aspects represent the most likely places to find wet snow. While loose wet snow instabilities should remain minor inconveniences in most places, they could become more problematic near terrain traps (like cliffs) where the terrain can magnify the consequences of any size avalanche.

Starting to get excited about the upcoming winter? Fuel the excitement with some high quality avalanche education either free online or in person at the California Avalanche Workshop. There is something of interest for everyone, regardless of the degree of prior knowledge. See the advisory page for more details.

Early Season Conditions Update #1

While overall snow depth remains shallow, wind slabs and basal facets are starting to show themselves as potential problems. At this point, early season forays into or below snow covered avalanche terrain without deliberate, educated snowpack assessment and companion rescue equipment is foolhardy. Daily avalanche advisories will resume once the snowpack becomes deep enough for over snow travel in widespread areas. Until that time, occasional updates to this page will occur as conditions warrant.

Early this morning, avalanche danger remains LOW for all elevations and aspects. Following the onset of snowfall, avalanche danger is expected to increase to CONSIDERABLE during the afternoon hours. Wind slabs and storms slabs are expected as the main avalanche problems.  Especially in areas that held snowcover prior to today's snowfall, natural and human triggered avalanches will be possible on slopes 35 degrees and steeper. The areas of greatest instability area expected near and above treeline on NW-N-NE-E aspects.

Pockets of MODERATE avalanche danger exist above treeline on all aspects on slopes 35 degrees and steeper due to lingering wind slabs. Near treeline and below treeline avalanche danger is LOW on all aspects. Isolated areas of unstable wind slab may remain near treeline, especially in complex terrain. LOW danger means that human triggered avalanches have become unlikely and areas of instability are isolated, not that avalanches will not occur.

 

The avalanche danger remains LOW on on all aspects and elevations. While avalanches have become unlikely, they are not impossible. Small avalanches can still occur in isolated areas or extreme terrain during LOW danger. Continue to use caution and watch for unstable snow on isolated terrain features when traveling in the backcountry.

It early season and numerous exposed or barely covered season-ending obstacles exist. While the avalanche danger has decreased, these hazards remain.

Avalanche danger remains LOW for all elevations and aspects. Triggering is unlikely but certainly not impossible given the current snowpack layering. Per the definition of LOW danger from the North American avalanche danger scale, small avalanches may still occur in isolated areas or extreme terrain during LOW danger. Use caution and watch for unstable snow on isolated terrain features when traveling in the backcountry. Shallow snow cover over rocks, stumps,and logs remains a significant hazard.

Avalanche danger remains LOW for all elevations and aspects. Normal caution is advised. Expect increased avalanche danger Tuesday/Wednesday as a well advertised storm impacts the region.

Human triggered avalanches remain likely today. CONSIDERABLE avalanche danger exists on near and above treeline NW-N-NE-E-SE aspects 35 degrees and steeper with MODERATE avalanche danger on the other aspects and elevations. Newly formed wind slabs on the wind loaded NW-N-NE-E-SE aspects in near and above treeline terrain represent the primary avalanche concern today but loose dry instabilities and isolated storm slabs may also exist in non wind loaded areas. 

MODERATE avalanche danger exists on all aspects in near and above treeline terrain on slopes 35 degrees and steeper due to presence of old hard wind slabs and smaller newly formed wind slabs. Human triggered avalanches remain possible today. Loose dry sluffs may remain possible on steep, sheltered, lower-elevation slopes as well. Evaluate the snow and terrain carefully before committing to a slope instead of letting the excitement of early season snow lead to poor decision making.

LOW avalanche danger continues for all elevations and aspects. The potential exists for the unlikely triggering of small avalanches in isolated areas. Continue to use accepted best practice travel techniques while traveling in or below avalanche terrain. Keep exposure limited to one person at a time and avoid grouping in avalanche run out zones.

LOW avalanche danger continues for all elevations and aspects. The potential exists for the unlikely triggering of small avalanches in isolated areas. Continue to use accepted best practice travel techniques while traveling in or below avalanche terrain. It is still early season and the snowpack is relatively shallow. Numerous barely covered rocks, stumps, logs, and other hazards exist.

LOW avalanche danger will persist on all aspects and elevations during the day today. Some unstable snow could still exist on isolated terrain features due to the presence of lingering persistent weak layers. The avalanche danger will increase quickly tonight and rise to CONSIDERABLE as new wind slabs and some small storm slabs form overnight. These avalanche problems mean that careful snowpack evaluation, cautious route-finding and conservative decision-making will be essential tomorrow (and tonight).

Avalanche danger is LOW for all elevations and aspects. Small isolated pockets of instability may linger both above and below treeline due to recently formed wind slabs and storm slabs. Normal caution is advised. Travel one at a time while in or below avalanche terrain. Avoid grouping up in marginal islands of safely or in avalanche run out zones. Maintain situational awareness and recognize the boundaries of avalanche terrain while on the fly.

 

LOW avalanche danger continues for all elevations and aspects. Small isolated pockets of unstable snow may exist. Normal caution is advised. It is still early season with generally shallow snow coverage and numerous poorly covered obstacles to hit.

Low avalanche danger remains on all aspects and elevations.  Watch for unstable snow on isolated terrain features.  Early season snowpack conditions exist with the potential to collide with many obstacles.  The avalanche danger will rise as the storm system arrives late tonight and throughout Thursday.

CONSIDERABLE avalanche danger exists on slopes steeper than 32 degrees on NW-N-NE-E-SE aspects in near and above treeline terrain. MODERATE avalanche danger exists on these aspects in below treeline terrain. Wind slabs will exist on wind loaded slopes, and persistent slabs may exist on sheltered northerly aspects toady. Careful snowpack evaluation, cautious route-finding, and conservative decision-making are essential. Human triggered avalanches will be likely today.

CONSIDERABLE avalanche danger will form today above and below treeline on NW-N-NE-E-SE aspects on slopes 32 degrees and steeper. MODERATE avalanche danger for all other areas. Wind slabs and persistent slabs are todays avalanche problems. Significant uncertainty surrounds the potential for buried surface hoar below treeline on NW-N-NE aspects. Where surface hoar is buried, avalanche danger may exceed the regional rating of CONSIDERABLE and avalanche activity may occur on low angle slopes down to 25 degrees.

Pockets of Moderate avalanche danger exist on all aspects above treeline and on NW-N-NE aspects near treeline and below treeline.  Low danger exists for all other areas.  Avalanche problems for today consist of wind slabs and persistent slabs.  In isolated areas, human triggered avalanches are possible today.  Evaluate snow and terrain carefully, identify features of concern.

The avalanche danger has decreased to LOW for all elevations and aspects. LOW avalanche danger means that while avalanche activity may be unlikely, it is not impossible. Unstable snow in the form of small isolated wind slabs or persistent slabs could still exist on isolated terrain features especially in complex or extreme terrain.

MODERATE avalanche danger exists at all elevations on NW-N-NE aspects and in near and above treeline terrain on E-SE aspects on slopes 32 degrees and steeper due to the combination of wind slabs and persistent slabs. Where persistent slabs exist avalanches could occur on lower angle slopes as shallow as 25 degrees. Evaluate snow and terrain carefully before committing to a slope. If more snow falls than forecast, the avalanche danger could increase. Human triggered avalanches are possible today. 

Increasing avalanche danger will occur throughout the day today and tonight. CONSIDERABLE avalanche danger will exist today both near and above treeline on NW-N-NE-E-SE aspects as well as below treeline on NW-N-NE aspects on slopes 32 degrees and steeper. For all other areas, MODERATE avalanche danger exists. HIGH avalanche danger is expected to form tonight and last into the pre dawn hours tomorrow.

 

Avalanche danger is moderate on all aspects and elevations on slopes steeper than 35 degrees due to wind slabs and deep persistent slabs.  Our snowpack has doubled in size in most areas with a heavy, wet, dense layer of new snow.  Human triggered avalanches are possible today with large destructive avalanches possible in some areas.  Evaluate snow and terrain carefully.

Human triggered avalanches will remain possible today on slopes 35 degrees and steeper at all elevations on NW-N-NE-E-SE aspects and in above treeline terrain on all aspects. Wind slabs, loose dry avalanches, and some isolated storm slabs represent the main avalanche problems today with deep slabs on NW-N-NE aspects representing a very unlikely but not impossible problem. Evaluate snow and terrain carefully before committing to a slope.

MODERATE avalanche danger continues above treeline on all aspects and near treeline on NW-N-NE-E-SE-S aspects on slopes 35 degrees and steeper. For all other areas expect LOW avalanche danger. Wind slabs remain an ongoing problem with two small human triggered wind slab avalanches reported yesterday.

 

Avalanche danger is low for all aspects and elevations.  Watch for unstable snow on isolated terrain features.  Normal caution is advised today-use basic travel techniques to minimize risk.

This advisory will cover Dec. 31 and Jan. 1. The next update to the avalanche advisory will occur on Jan. 2 at 7:00 am. 

The avalanche danger remains low on all aspects and elevations. While avalanches remain unlikely, some unstable snow could linger on isolated terrain features. Continue to use normal caution when traveling in the backcountry.

LOW avalanche danger continues for all elevations and aspects. Small wind slabs are a lingering issue today near and above treeline on NW-N-NE aspects. These wind slabs might remain sensitive to human triggering in isolated areas. Avalanche size is expected to remain too small to bury a person unless highly defined terrain traps are involved. Normal caution is advised.

 

Avalanche danger will rise to considerable today on slopes 32 degrees and steeper on all aspects and elevations due to wind slabs and storm slabs.  Natural avalanches are possible and human triggered avalanches will be likely today.  Areas of greatest danger will be along the Sierra Crest and South of Hwy. 50.  For other areas avalanche danger will range from Moderate to Considerable.  Dangerous avalanche conditions exist, cautious route finding and conservative decision making will be essential today. 

Human triggered avalanches remain possible today due to lingering wind slabs and storm slabs. MODERATE avalanche danger exists on all elevations and aspects on slopes 35 degrees and steeper. Evaluate snow and terrain carefully before committing to any slopes. 

Human triggered avalanches remain possible today due to new wind slabs and old and new persistent slabs. Persistent slabs exist on open slopes in near and below treeline terrain on W-NW-N-NE-E aspects. Wind slabs will exist on wind loaded NW-N-NE-E-SE aspects in near and above treeline terrain. MODERATE avalanche danger exists in those areas on slopes 32 degrees and steeper. Remotely triggered avalanches and avalanches that propagate long distances are possible today especially in near and below treeline terrain.

Unusual avalanche conditions persist with pockets of MODERATE avalanche danger in open areas at and below treeline on N-NE-E-SE aspects on slopes 35 degrees and steeper. Persistent slabs associated with the Jan 5 buried surface hoar layer exist in some areas. Where this weak layer is absent, LOW avalanche danger exists. Avoid steep terrain adjacent to areas of recent avalanche activity, even if the crown and debris are covered under a couple inches of new snow and now look old.

Considerable avalanche danger exists on NW-N-NE-E-SE aspects at all elevations due to persistent slabs and newly forming wind slabs.  On S-SW-W aspects at all elevations Moderate avalanche danger exists.  Careful snowpack evaluation, cautious route finding and conservative decision making are essential today.

On slopes steeper than 30 degrees, CONSIDERABLE avalanche danger exists on NW-N-NE-E-SE aspects at all elevations due to a combination of wind slabs and persistent slabs. Large human triggered avalanches are likely and natural avalanches are possible. Unusual avalanche conditions exist. Avalanches on steeper slopes could be remotely triggered by a person standing in lower angle terrain or may be triggered in places traditionally considered safe. Careful snowpack evaluation, cautious route finding and conservative decision making are essential.

MODERATE avalanche danger continues at all elevations on NW-N-NE-E-SE aspects on slopes 32 degrees and steeper due to a combination of persistent slabs and storm slabs. Human triggered avalanches remain a near daily occurrence within the forecast area. Identify the necessary differences between managing wind slab and persistent slab avalanche problems and adjust terrain selection and travel practices accordingly. Increasing avalanche danger is expected tonight into tomorrow morning.

Moderate avalanche danger exists on all aspects and elevations through the morning hours.  As the incoming storm intensifies by mid day, avalanche danger will rise to considerable.  Wind slabs will develop on NW-N-NE-E-SE aspects near and above treeline and persistent slabs will be possible on N-NE-E aspects near treeline and below treeline on slopes 32 degrees or steeper.  Natural avalanche activity will become possible this afternoon with human triggered avalanche activity possible to likely all day.  

 

Even though avalanches have become more difficult to trigger, human triggered avalanches remain possible on some NW-N-NE-E-SE aspects at all elevations due to lingering persistent slabs and wind slabs. The persistent slabs could occur on slopes steeper than 32 degrees, while the wind slabs would be more problematic on slopes steeper than 35 degrees. The avalanche danger is MODERATE today, but the consequences of a human triggered avalanche would be serious. Evaluate snow and terrain carefully; identify features of concern.

Human triggered avalanches are likely today on NW-N-NE-E aspects and some W and SE aspects at all elevations on slopes steeper than 32 degrees due to newly formed wind slabs and the possibility of deep persistent slabs. The avalanche danger is CONSIDERABLE today. Today's avalanches could be large and have severe consequences and may occur in areas traditionally considered safe especially in the case of the deep persistent slabs. Careful snowpack evaluation, cautious route-finding and conservative decision-making are essential.

MODERATE avalanche danger is expected today above treeline on SE-S-SW-W-NW aspects on slopes 35 degrees and steeper in areas where new wind slabs form this morning. For all other areas, LOW avalanche danger exists. Normal caution is advised. Very isolated deep persistent slab avalanches are unlikely but not impossible in open near treeline and below treeline areas on N-NE-E aspects on slopes 32 degrees and steeper.

Avalanche danger remains low on all aspects and elevations.  Isolated areas of instability may exist.  Normal caution is advised.

CONSIDERABLE avalanche danger exists on all aspects and elevations on slopes steeper than 35 degrees due to a combination of wet snow instabilities caused by rain on snow and newly formed wind slabs at the upper elevations. Human triggered loose wet avalanches and wind slab avalanches are likely today and some isolated wet slab avalanches may be possible. People traveling in the backcountry should make careful snowpack evaluations, use cautious route-finding and conservative decision-making, and expect to get very wet.

Upper end MODERATE avalanche danger exists today for all elevations and aspects on slopes 35 degrees and steeper due to a combination of newly formed wind slab, storm slab, and loose dry avalanche problems. Natural avalanche activity in not expected today, but isolated natural activity is certainly not out of the question. Human triggered avalanches are expected today and should not be a surprise to backcountry travelers.

Moderate avalanche danger exists on all aspects near treeline and above treeline due to existing wind slabs and new wind slab development due to shifting winds.  Low avalanche danger exists on all aspects below treeline.  Evaluate snow and terrain carefully, identify features of concern.

MODERATE avalanche danger may form on sun-exposed near and below treeline E-SE-S-SW-W aspects as well as on some above treeline SE-S-SW aspects due to the possibility of loose wet snow instabilities. Wet surface snow and small instabilities like pin wheels and roller balls can indicate that loose wet avalanches have become possible. The amount of warming that actually occurs today will dictate how widespread these possible wet snow instabilities may be. 

LOW avalanche danger exists this morning. As the day warms up, some pockets of MODERATE danger may form on sun-exposed SE-S-SW aspects steeper than 35 degrees up to 9500 ft. due to the possibility of some small loose wet snow instabilities like pinwheels, roller-balls, and point release avalanches. Most of these loose wet snow instabilities should remain small and isolated, but a few could entrain enough snow to create issues for backcountry travelers on slopes that experience the most warming. 

Early this morning, LOW avalanche danger exists for all elevations and aspects. Pockets of MODERATE avalanche danger will form quickly in response to daytime warming on E-SE-S-SW aspects at all elevations on slopes 35 degrees and steeper. On W-NW-N-NE aspects, avalanche danger will remain LOW. Isolated wind slabs may exist above treeline on S-SW-W-NW-N aspects, but are not expected to be a widespread avalanche problem today.

Low avalanche danger will exist on all aspects and elevations in the early morning hours.  As daytime warming begins, pockets of Moderate avalanche danger will become possible on E-SE-S-SW aspects at all elevations due to loose wet avalanche instabilities.  On W-NW-N-NE aspects at all elevations, avalanche danger will remain Low throughout the day.

LOW avalanche danger exists this morning while the snowpack remains frozen. As the day warms up and last night's refreeze melts, pockets of MODERATE danger will quickly form slopes steeper than 35 degrees on E-SE-S-SW aspects due to the possibility of loose wet avalanches. Small human triggered roller balls, pinwheels, and point-releases should comprise most of the loose wet activity, but some loose wet avalanches could involve enough snow to cause problems for backcountry travelers. 

LOW avalanche danger continues for all elevations and aspects. Human triggered loose wet avalanches may occur this afternoon in isolated areas on E-SE-S-SW aspects on slopes 37 degrees and steeper. Normal caution is advised.