Avalanche Awareness System

Table of Contents

Trail Report Red Flags Weather

Terrain Snowpack Human

Route Selection

Avalanche Safety is a state-of-mind and a set of learned skills. Your safely and your parties depends on your skills of interpreting the relationship of Terrain, Weather, Snowpack and Human behavior as it relates to the "I can" attitude as well as, caring the necessary tools to find someone that gets buried in an avalanche.

Your safety starts with following the Avalanche System Protocol that is listed below. This system consist of three parts.

First: Understanding the relations between the four critical variables of avalanche, and being able to use the same methodology each and every time to test the snows stability. This can be achieved by conducting the same snow stability tests in the same matter and at similar sites that are prone to avalanche activity. Considering: slope, angle, aspect, elevation, location, and conducting stability tests that look for Shear Quality, Failure Depth, Compression Test, and Rutschblock as part of this equation. The sites that we will be conducting our stability tests at are still under review. Tests areas that are being considered:

The SE slope near the top of the Rave trail by the weather station.

NW facing slope near the Rave trail just below Garfield Trail..

SW slope near the avalanche zone near Vida Ridge on the East Rim. .

Test site near the Watchman on the SW facing slope.

SE slope on Ranger Hill.

All slopes that patrollers cross or ski during their daily activities that have possible avalanche potential..

SW slope of Garfield, near Wildflowers upper ridge.

Secondly: Avalanche safety requires you to carry:

A metal bladed shovel.

A 10' or longer probe.

Reliable tracker

A working radio with extra batteries.

One patroller caring a snow saw to conduct snow stability testing.

Note paper to record results.

Thirdly: Reporting testing methodologies and results. These results need to be written in the trail report so anyone reading the report can understand what you are reporting.

Example. if you get a 2 result on the Rutschblock- you would write it up as a (Rutschblock -R2 -RED LIGHT) on the trail report.

Most importantly: the RED LIGHT would indicate a" NO-GO" situation and your route selection would require you to find safe passage around the avalanche area.

When conducting hasty pits, observations concerning layering, slope, angle, aspect, elevation, location, and results of stability tests for Shear Quality, Failure Depth, Compression Test, and Rutschblock need to be added to the daily report.

Other notable criteria could include:

Red Flag avalanche activity.

RED FLAG Warnings

     1. Observing natural occurring avalanches                       2. Observing recent avalanches              3. Hearing whoomphing noises

     4. Heavy dense snowfall or rain on top of new snow fall. 5. New snowfall greater than 12 inches, any density

    6. New snowfall rate greater than 1 inch per hour.          7. Wind loading greater than 15 mph.

    8. Long/clear/cold spells followed by significant snowfall or wind loading.

    9. Storms that begin cold and end warm.                         10. Rapid temperature rising during the day.

   11. Prolonged period of above-freezing temps.                 12. Intense sun especially near cliff bands.

An Avalanche Hazard Evaluation Checklist (click on link to view checklist) should always be carried in your radio harness and can be seen below. This checklist visual aid is a great way to tie all of your data together and will assist you in your decision-making process. Assigning a red, yellow, or green light to each of the four variables can clear up what might be a difficult decision. For example, if you are skiing low angle slopes, or green light terrain, all of the other factors can be red because the slope cannot avalanche. Or you can be on a steep slope, red light terrain, but if the other variables are green, go for it! The point is, this check list will help you if you have reached your goal, but aren't sure how to proceed. Stick with the data. Answer all the questions as it relates to the Avalanche Triangle and use the Interpreting Results KEY to aid your in your answer.

The interrelationship of four critical variables -- terrain, weather, snowpack, and human determines whether or not a potential avalanche hazard exists. Although these important variables are frequently changing, these changes are often detectable. Not only can critical information be observed, it can be measured, tested, evaluated, and acted upon. The bottom line is that our route selection and hazard evaluation decisions are only as good as the data we seek -- the primary causes of avalanche accidents are attitude and ignorance. Our attitude "filters" the data and warps it to our needs or desires. Our ignorance prevents us from seeking the answers before hand. Warning: Using this checklist may save your life. Follow these simple steps:

1) Seek out critical data.

2) Evaluate the potential level of hazard (red, green, yellow).

3) Add a level of caution for the "unknown".

4) Continually re-evaluate your situation without letting your attitude persuade you away from the facts..

*HAZARD LEVEL SYMBOLS: Think of data as being red, green, or yellow lights. G = Green light (go, OK), Y = Yellow light (caution, potentially dangerous), R = Red (Stop/Dangerous).

*This checklist is from Snow Sense, by Jill Fredston and Doug Fesler. Available from The Alaska Mountain Safety Center, 9140 Brewsters Drive, Anchorage, Alaska 99516, (907)-345-3566.

WEATHER: Has the weather been contributing to instability?

Look at past weather reports, weather book in dispatch, view weather data from the weather stations links on the ski patrol website before coming to Crater Lake.

Snow Pack Report Click here on hot link to attain information from the three different weather stations in the park.

Temperature. When the temperature is extremely low, settlement and adhesion occur slowly. Avalanches that occur during extreme cold weather usually occur during or immediately following a storm. At a temperature just below freezing, the snowpack stabilizes quickly. At temperatures above freezing, especially if temperatures rise quickly, the potential for avalanche is high. Storms with a rise in temperature can deposit dry snow early, which bonds poorly with the heavier snow deposited later. Most avalanches occur during the warmer midday.

Precipitation. About 90 percent of avalanches occur during or within twenty-four hours after a snowstorm. The rate at which snow falls is important. High rates of snowfall (2.5 centimeters per hour or greater), especially when accompanied by wind, are usually responsible for major periods of avalanche activity. Rain falling on snow will increase its weight and weakens the snowpack.

TERRAIN: Is the terrain capable of producing an avalanche?

Answer those questions as it relates to the area you plan on skiing?

Slopes as gentle as 15 degrees have avalanched. Most avalanches occur on slopes between 30 and 45 degrees. Slopes above 60 degrees often do not build up significant quantities of snow because they are too steep.

Slope Aspect: Snow on north facing slopes is more likely to slide in midwinter. South facing slopes are most dangerous in the spring and on sunny, warm days. Slopes on the windward side are generally more stable than leeward slopes.

HUMAN: Could you be a trigger or a victim, and are you prepared for the consequences?

SNOWPACK: Could the snow fail?

Do one or several of the stability tests listed below to determine current conditions at that point in time and place. See snow stability testing methods links on top of this page.( Rutschblock, Shear, Compression, Forecasting, and Trail Tests.

Stability Analysis. Look for nature’s billboards on slopes similar to the one you are on.

Evidence of Avalanching. Look for recent avalanches and for signs of wind-loading and wind-slabs.

Fracture Lines. Avoid any slopes showing cracks.

Sounds. Beware of hollow sounds—a "whumping" noise. They may suggest a radical settling of the snowpack.

Route Selection

The safest routes are on ridge tops, slightly on the windward side; the next safest route is out in the valley, far from the bottom of slopes.
Avoid cornices from above or below. Should you encounter a dangerous slope, either climb to the top of the slope or descend to the bottom—well out of the way of the run-out zone. If you must traverse, pick a line where you can traverse downhill as quickly as possible. When you must ascend a dangerous slope, climb to the side of the avalanche path, and not directly up the center.
Take advantage of dense timber, ridges, or rocky outcrops as islands of safety. Use them for lunch and rest stops. Spend as little time as possible on open slopes.
Since most avalanches occur within twenty-four hours of a storm and or at midday, avoid moving during these periods. Moving at night is tactically sound and may be safer.