ASC Avalanche Forecasting & Danger Ratings 3

Question 1

When applying a public avalanche forecast, what does the recommended 'distribution' of a danger rating indicate?

Accepted Answer

Which elevations and aspects are most affected by the rated danger level

Answer

Distribution specifies which elevation bands (alpine, treeline, below treeline) and aspects are most affected by the identified danger level and avalanche problems.

Question 2

A forecaster rates the danger at Considerable (3) for Persistent Slabs above treeline on north and east aspects. A guide is planning a route on a moderate north-facing slope at alpine elevation. How should the guide interpret this forecast?

Accepted Answer

The route falls squarely in the most affected terrain and should be avoided or requires careful evaluation

Answer

The guide's planned route matches all the high-risk criteria — north aspect, alpine elevation, and a slope angle within the range of human-triggered persistent slabs — requiring serious evaluation or avoidance.

Question 3

What is the primary reason forecasters update the avalanche danger rating daily?

Accepted Answer

Snowpack conditions, weather, and the reactivity of weak layers change continuously

Answer

Weather events, temperature changes, and snowpack evolution alter avalanche conditions on a daily basis, requiring forecasters to reassess and update the danger rating regularly.

Question 4

What is the significance of 'recent avalanche activity' as an instability sign when evaluating a forecast in the field?

Accepted Answer

Natural avalanche activity confirms that the snowpack is releasing and validates elevated danger ratings

Answer

Natural avalanche activity — regardless of aspect — confirms that the snowpack is releasing and is one of the most reliable signs that the avalanche danger is real and elevated.

Question 5

A 'whumpf' sound heard while traveling in the backcountry most directly indicates:

Accepted Answer

Sudden collapse of a weak layer beneath a slab, a strong sign of instability

Answer

A whumpf is the audible and tactile collapse of a weak layer beneath a slab, indicating that the snowpack has the structure needed to produce an avalanche and is a critical instability sign.

(ASC) Avalanche Safety Certification Practice Test

(ASC) Avalanche Safety Certification Practice Test

ASC Avalanche Forecasting & Danger Ratings 3