OCR Text |
Show Contributory Avalanche Factor Values Factor 1. Old Snow Depth 2. Old Snow Surface 3. New Snow Depth 4. New Snow Type 5. Average Density 6. Snowfall Intensity 7- Precipitation Intensity 8. Settlement 9. Wind 10. Temperature Definitely Favorable to Large Avalanches 24" or sufficient to cover surface obstructions. Crusts. Avalanche action probably confined to surface 12". Must be associated with wind Very dry, very wet, damp in large quantities. Granular and pellet forms. Transition type. .11 and above; .06 and below. Abnormal density for the type. Settlement is very important. l"/ hr. or higher with critical wind. 0.6 or higher if wind well above critical, level. ,10"/ hr. or higher, continuously. Wind action important, 15$ or less 15- 25$ is borderline. 15 mph plus or minus, in combination with heavy trans port of snow. Lee exposures are most hazardous Rising during a storm. Very low during and after a storm. Radical changes. Rapid rise after a storm. 24 hrs. continuous thaw. Definitely Unfavorable to Large Avalanches Insufficient to cover surface obstructions. Loose or damp snow. If avalanches occur on top of loose snow, penetration likely. Less than 12" if underlying snow is stable. Normal dry crystalline. Damp in moderate quantities. Between .07 and « i09 the factor is essentially neutral. Settlement important. ,5"/ hr. or less. High S. I.' s of short duration are neutral. Less than .10"/ hr. High P. I.' s of short duration are neutral. 35$ and above. Between 25- 35$ other factors more important. Below 10 mph or with little transport of snow. Windbeaten exposures are least hazardous. Normal temperature patterns are neutral. - 53 - |