Snow types met in highway snow removal

Snow falling on the west slopes of the Cascades in Washington is usually of the wet type with large flakes of soft texture. Snow falling east of the Cascades’ summit is usually dry snow of small flakes due to the colder temperatures. ‘Tapioca’ snow is peculiar to the Columbia River area in Southern Washington, and consists of snow globules which form a slush soon after falling. High velocity north westerly winds during rain storms at temperatures around freezing, form an icing within a few minutes after falling. A third common snow type is a dry, fine drifting powder which is hard to compact and easily shifted by changing winds. Snow removal from highways with primitive and modern equipment is illustrated in photographs.