http://FMSAC.org
MSAC Avalanche Advisory Print E-mail

  The Mt. Shasta Avalanche Center - US Forest Service  

Link to video of 5/30 slab avalanche near Helen Lake 

A good sized wet avalanche released at 7 pm in the Trinity chutes in upper Avalanche Gulch (13,200 ft.) and traveled to the right moraine above Helen at around 10,800 ft.  No one was injured, but it did come close to hitting a few people. 

We had a large avalanche during the Martin Luther King Jr. storm of 2010 which paralyzed the City of Mt. Shasta.  The slide traveled around 3.25 miles, dropped 5800 vertical feet and is still 20 ft. deep in July!  It also had a strong air blast in front of it which snapped limbs and small trees.  The evidence of this is now visible in July:
 

January avalanch debris in July, 2010

Tree debris from the air blast during a large avalanche on Mt. Shasta, January 2010.  Photo July 10, 2010, Eric White

 

Have a few minutes to help? Currently, FMSAC is working on planning and long term goals. We would really appreciate your input. Please take a minute or two to complete our survey by clicking here. Thank you!
                  
April 18, 2010 was our last avalanche advisory of the season.  To look at the avalanche advisories of the season, go to "Archived Advisories" in the left column of this page, or click here.  Thanks for your support!!!  A big thank you to FMSAC for providing this  web page, paying for maintenance of our weather stations, and other budget funding!  We also thank our families for patience and support through early morning hours and long work days!
General Information Pertaining to Spring & Summer Avalanche Conditions:

Spring Time brings us the possibility of corn snow, powder or rain.  Remember it is possible for spring storms to dump impressive amounts of snow and rain.  Most of the avalanche activity associated with these spring storms occurs during or shortly after the storm event.  Timing is critical when playing in avalanche terrain.

Terrain:  Remember most of the terrain that we like to play on is greater than 30 degrees.  Avalanches are possible on anything steeper than 30 degrees, especially wet snow avalanches.  Avoid cornices, rock bands, terrain traps and runout zones of avalanche paths.

Weather:  When there are storms in the spring, they can bring impressive amounts of rain, snow and wind.  This can greatly increase the avalanche danger during and after storms.  Heed the signs: Wind (significant snow transport and depositions), Temperature (rapid/prolonged warming, which in turn weakens the snowpack), and Precipitation (Snor or rain add weight and stress to the current snowpack).

SnowpackIf snow accumulates, give the snowpack a chance to adjust to the new snow load before you play on or near steep slopes (greater than 30 degrees).  Most direct action avalanches occur within 24-48 hours of recent snowfall.  Watch for obvious signs of snowpack instability such as recent natural avalanche activity, collapsing of the snowpack (often associated with a “whumphing” sound), and shooting cracks. If you see these signs of instability, limit your recreation to lower angle slopes.

If during the warmer parts of the day you see signs that the surface snow is getting warm, such as snowballs rolling down the slope or you find the snow is sloppy enough that you sink in to your boot tops, it would probably be a good idea to play it cool and find another slope to play on or under, or call it a day. If this does happen, avalanches can be triggered.  If the snow only freezes at night, an early start will be imperative.  The snow does soften quickly and will become increasingly unstable throughout the day as it is warmed by solar radiation.  If the snow is soft early in the morning due to a lack of freezing overnight, it is probably a good idea to play another day.

Human Factor: Don’t forget to carry and know how to use avalanche rescue gear. You should NOT be skiing or climbing potential avalanche slopes without having beacons, shovels, and probes.  Only one person in a group should be exposed to potential avalanche danger at a time.  Remember, climbing, skiing, and riding down the edge of slopes is safer than being in the center.  Just because another person is on a slope doesn’t mean that it is safe.  Be an individual!  Make your own decisions.  Heed the signs of instability: rapid warming, “whumphing” noises, shooting cracks, snowing an inch an hour or more, rain, roller balls, wind loading, recent avalanche activity.

Wet slide in Avalanche Gulch on Mt. Shasta during July.Wet Slides:  While both soft slabs and hard slabs have occurred on Mt. Shasta during the spring and summer, wet slides are more common.  These types of avalanches are more difficult to predict, harder to trigger, and not as fast as other avalanches.  While wet slides are more difficult for people to trigger, many of the popular climbing routes on Mt. Shasta are in avalanche pathways.  Wet slides occur more frequently when temperatures stay above freezing for 24 hours or longer, or moderate to heavy rain falls.  Watch for:  unusually warm temperatures, sinking into slush to your boot tops, water running on or in the snow pack, roller balls, wet sluffs, ski pole sinks to hand grip, moderate to heavy rain fall, recent wet slides.  Glide avalanches are another type of wet slide and are also more common in Spring.  We see more of these in the Castle Crags Wilderness and Castle Lake area where smooth rock surfaces exist.

The Five Red Flags of Avalanche Danger any time of year include:  1) Recent/current avalanche activity  2) Whumpfing sounds or shooting cracks  3) Recent/current heavy snowfall  4) Strong winds transporting snow  5) Rapid warming or rain on snow. 


Morning looking up Broadway ridge at
8000 ft. Mt. Shasta, winter 2010Morning photo looking up Broadway ridge on the south side of Mt. Shasta at 8000 ft.  Note wind patterns and texture.  Photo by Mike Hupp/Dawn Patrol Images

2009/2010 Winter Season:  Drought conditions were experienced from 2006/2007 through 2008/2009.  In October of 2009, Columbus day brought a strong storm to our area.  A period of well below normal temperatures in the first half of December created a widespread weak layer of facets and depth hoar.  Winter finally kicked in and we slowly watched the weak layer get buried and disappear in January.  A huge storm beginning on Martin Luther King Jr. Day in January brought 8-10 feet of snow (12-13 inches of water - SWE) to the mountain and paralyzed the local town with heavy snow snapping trees causing widespread damage.  Overall, the winter was warm and wet with precipitation in the City of Mt. Shasta at 125% of normal on 4/22/10.  The April snow survey showed snow pack depth in our area at 127% of normal.  El Nino conditions became strong this winter and are expected to return to neutral this summer.  Winds were not as strong as normal this year and were more frequently from the SE as opposed to our normal big winds from the NW.  Many natural avalanches occurred during and shortly after storms, with one large avalanche during the big January storm event.  That slide covered 5600 ft. vertically and 3 miles horizontally, piling up 30+ ft. deep over several acres.  Several human triggered avalanches occurred with only minor injuries and no fatalities this season.

The final avalanche advisory for the season was 4-18-22.  Remember that the potential for avalanches exists as long as snow on steep slopes exists, so be observant looking for clues to instability.  We will be updating the Climbing Advisory page weekly as conditions change: www.shastaavalanche.org.  Avalanche information will be posted when significant storms are expected.  We would like to thank you for your interest in this service.  This includes everyone who sent in avalanche and snowpack observations. These observations are a vital part of the daily avalanche hazard assessment and we really appreciate your input. We hope that we have helped in making your backcountry experience safer.  If you have any suggestions or comments please feel free to contact us:  U.S. Forest Service, Mt. Shasta Avalanche Center, 204 W. Alma St.  Mt. Shasta, CA 96067.  We look forward to sharing more avalanche information with you next season.  In the mean time, enjoy your spring and summer, and be safe out there!         

Heavy snowfall on 4/10-4/12 caused widespread natural avalanches in the Castle Lake area.  Many slides piled up on the south end of the lake like the one above.  Photo by Chris Carr.

Some of this seasons video links:
Link to video showing results of Rutschblock near Castle 3/20/10
 

Link to video showing criblet ridge after avalanche 3/2/10

Link to video showing Rutschblock stability test 2/27/10

Link to video showing Extended Column Test 2/27/10

Link to video showing Rutschblock stability test 2/5/10

Link to video showing Rutschblock stability test 1/14/10

Link to video showing stability test 1/9/10 

Link to video showing the 1/2/10 Pelican Butte avalanche accident (recovered alive) 

Link to short video #1 from 1/2/10 showing wind loading Mt. Shasta

Link to short video #2 from 1/2/10 with Rutschblock test results, Mt. Shasta

Link to short video showing shallow snow pack and facet layer on ground, 12/24/09.

Go to "Photos/Avy Shots" for photos of recent avalanches.  

Please report weather and snow observations- you could help save a life:  (530)926-9614  Thanks!  


 

The Five Red Flags of Avalanche Danger any time of year include:  1) Recent/current avalanche activity  2) "Whumpfing" sounds or shooting cracks  3) Recent/current heavy snowfall  4) Strong winds transporting snow 5) Rapid warming or rain on snow.

  

 


Ranger Station Info

Avalanche/Climbing Hotline (530)926-9613
Avalanche Specialists & Lead Climbing Rangers:
Eric White & Dan Towner
Climbing Rangers:

Nick Meyers, Jon Dove & Forrest Coots
For more information call: (530) 926-4511
Summer hours:  Mon - Sun, 8am-4:30pm
Mt. Shasta Avalanche Center and Wilderness Dept.
Mt. Shasta Ranger Station
Shasta-Trinity National Forest
204 West Alma Street
Mount Shasta, CA 96067


Live Shasta Cam

Mount Shasta Snow Cam courtesy of SnowCrest, Inc.
Courtesy of SnowCrest, Inc.