OCR Text |
Show High alpine zone ( Berthoud Pass, Arapaho National Forest, Colorado. Latitude 39° 48' N., Longitude 105° 47' W.). 1. Moderate snowfall, about 200 inches per year. 2. Few storms depositing 12 inches or more of snow. 3. Low temperatures, frequently below 0° F. 4* Very strong wind action. 5. Altitudes of 10,000 to 13,000 feet. 6. Principal hazard: slab avalanches, often delayed action. Middle alpine zone ( Alta, Wasatch National Forest, Utah. Latitude 40° 36' N., Longitude lli° 38' W.). 1. Heavy snowfall, about 400 inches per year. 2. Frequent storms depositing 12 inches or more of snow. 3. Medium temperatures, occasionally below 0° F. 4. Strong wind action. 5. Altitudes of 8,000 to 11,000 feet. 6. Principal hazard: direct action loose snow and slab avalanches. Coastal alpine zone ( Stevens Pass, Wenatchee National Forest, Washington. Latitude 47° N., Longitude 121° W.). 1. Very heavy snowfall, about 600 inches per year. 2. Ifeny storms depositing 12 inches or more of snow. 3. Moderate temperatures, seldom below 0° F. 4. Considerable wind action. 5. Altitudes of 4,000 to 7,000 feet. 6. Principal hazard: direct action damp and wet snow avalanches. The three alpine zones overlap. Each can and does develop all types of avalanche hazard. The principal advantage of the three stations is division of work and concentration on the hazards of highest frequency. Figures 3 to 6 are graphic and tabular comparisons of the zones. Alta is used as the basis of comparison since it has available the most descriptive data. When the other stations have been in operation over a period of years, it will be possible to make sharper distinctions between the zones. - 14 - |