Which of the following is a predictor?

• A. Rapid and recent snowfall
• B. Dry spell with no thaw
• C. Surface crust formation
• D. Stable soil moisture

Answer: (A)

Rapid and recent snowfall directly loads the snowpack with fresh material, often forming slabs over weak, poorly bonded layers. This rapid addition of weight creates instability quickly, and the bonding between new snow and the existing layers hasn’t had time to strengthen, making a slide more likely. In avalanche forecasting, this freshly deposited snow is a strong short-term indicator of increased danger because it signals potential failure planes under a trigger such as a skier, additional loading, or sudden warming.

A dry spell with no thaw reduces new load and tends to stabilize the snowpack, so it’s not a signal of growing avalanche risk. Surface crust formation describes a particular surface condition that can influence how a layer might fail, but on its own it isn’t as reliable a short-term predictor of widespread danger. Stable soil moisture pertains to ground conditions and does not directly reflect the stability of the snowpack, so it doesn’t indicate imminent avalanche hazard.