Avalanche Forecasting & Danger Ratings Flashcards
7 cards from real ASC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Avalanche Forecasting & Danger Ratings flashcards as text
How many danger levels are on the North American Public Avalanche Danger Scale?
Answer: 5
The North American Public Avalanche Danger Scale has 5 levels: Low, Moderate, Considerable, High, and Extreme.
Which avalanche danger level is associated with the highest number of avalanche fatalities historically?
Answer: Considerable (3)
Considerable (Level 3) is associated with the most avalanche fatalities because it is the level at which human-triggered avalanches become likely and many travelers underestimate the risk.
On the North American Avalanche Danger Scale, at which danger level are 'natural and human-triggered avalanches certain'?
Answer: Extreme (5)
At Extreme (Level 5), natural and human-triggered avalanches are certain, and large to very large avalanches will occur.
What does the term 'avalanche problem' refer to in a forecast?
Answer: The type of snow instability likely to produce avalanches
An avalanche problem describes the type of snow instability present — such as Wind Slab, Storm Slab, or Persistent Weak Layer — that is most likely to produce avalanches.
Which organization is primarily responsible for issuing public avalanche forecasts in the United States?
Answer: The National Avalanche Center (NAC) and regional avalanche centers
The National Avalanche Center (NAC) coordinates a network of regional avalanche centers that issue public forecasts across the US.
What is the primary purpose of including 'likelihood' in an avalanche forecast?
Answer: To indicate the probability that avalanches will be triggered
Likelihood in a forecast communicates the probability that a person will trigger or encounter an avalanche, ranging from unlikely to certain.
What does 'size' in an avalanche problem assessment refer to?
Answer: The destructive potential of the avalanche relative to a person or structure
Size in avalanche forecasting refers to the destructive potential of the avalanche — from D1 (relatively harmless) to D5 (could destroy a large building or forest).