The addition of weight on top of a snowpack, usually from precipitation, wind drifting, or a person.
Loading from Wind:
As we know, snow does not like rapid changes, especially a rapid increase in weight piled on top of a buried weak layer. By far, the quickest way to load snow onto a slope is from wind drifting. Wind can deposit snow ten times more rapidly than snow falling out of the sky.
Wind erodes snow from the windward (upwind) side of an obstacle and deposits snow on the leeward (downwind) side. Deposited snow looks smooth and rounded. You should always beware of recent deposits of wind drifted snow on steep slopes.
Loading from Snow or Rain:
The second fastest way to load a buried weak layer is through new snow or rain. Rapidly-added weight almost always means rapidly-rising avalanche danger. Remember that more precipitation usually falls at higher elevations than lower elevations and more on the windward sides of mountain ranges than the leeward sides (with the exception of wind drifting near the ridges).