Avalanche (Avi) Practice Exam

Understanding how snowfall rate influences avalanche risk in Continental climates is the main point being tested. In these climates, snowpack stability is sensitive to how fast new snow piles on. When fresh snow accumulates at about one inch per hour, the load is enough to push the snowpack toward instability without requiring extremely heavy storms. The rapid loading can promote the development of weak layers beneath the surface and reduce bonding, especially under typical temperature gradients for Continental regions. This creates a higher potential for avalanches when additional loading or wind drift occurs later. Slower rates, such as half an inch per hour, tend to allow more time for bonding and settling, which reduces the likelihood of sudden destabilization. Heavier rates, like 1.5 to 2 inches per hour, represent more extreme loading that can also be risky, but the threshold most often cited for Continental climates as the critical rate is around one inch per hour. That makes the one-inch-per-hour rate the best match for signaling when loading starts to meaningfully affect snowpack stability in this climate.