Abstract
Snow avalanches are a significant hazard in mountainous environments around the world. This paper investigates the major February 1986 avalanche cycle that occurred in the western United States, and broadly analyzes the avalanche, snowpack, and weather conditions at twenty sites. These analyses suggest that the avalanche cycle resulted from the interaction of a relatively `normal' snowpack with an exceptional storm event, which was particularly noteworthy for the amount of precipitation it produced. Composited 500-hPa anomaly maps show the event resulted from an uncommonly persistent blocking pattern that resulted in a strong zonal flow and copious moisture being funneled over the western United States. Understanding severe and widespread avalanche cycles may improve our long-term forecasting of these events, and help mitigate theresulting avalanche activity.
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Arkin, P. A. and Janowiak, J. E.: 1987, The global climate for December 1985-February 1986: conflicting ENSO signals observed in the equatorial Pacific, Mon. Wea. Rev. 115, 297–316.
Armstrong R. L. and Armstrong, B. R.: 1987, Snow and avalanche climates of the western United States, Int. Assoc. of Hydrol. Sci. Publ. 162, 281–294.
Armstrong, B. R. and Williams, K.: 1992, The Avalanche Book, Fulcrum Press, Golden, Colorado, 240 pp.
Bachman, D.: 1999, European avalanches of 1998-99, The Avalanche Review 17(6), 11.
Birkeland, K. W.: 1996, Avalanche hazard analysis for the various alternatives, New World environmental impact statement, Gallatin National Forest, Bozeman, Montana, USA, 25 pp.
Birkeland, K. W.: 1998, Terminology and predominant processes associated with the formation of weak layers of near-surface faceted crystals in the mountain snowpack, Arctic and Alpine Res. 30, 193–199.
Birkeland, K. W. and Mock, C. J.: 1996, Atmospheric circulation patterns associated with heavy snowfall events, Bridger Bowl, Montana, U.S.A., Mountain Res. and Dev. 16, 281–286.
Birkeland, K. W., Mock, C. J., and Shinker, J. J.: In press, Avalanche extremes and atmospheric circulation patterns, Ann. Glaciol. 32.
Björnsson, H.: 1980, Avalanche activity in Iceland, climatic conditions, and terrain features, J. Glaciol. 26, 13–23.
Butler, D. R.: 1989, Snow avalanche-dams and resultant hazards in Glacier National Park, Northwest Sci. 63(3), 109–115.
Calondar, G. P.: 1986, Ursachen, wahrscheinlichkeit und intensität von Lawinenkatastrophen in den Schweizer Alpen, Diplomarbeit Universität Zürich.
Cayan, D. R.: 1996, Interannual climate variability and snowpack in the western United States, J. Climate 9, 928–948.
Davis, R. E., Jamieson, B., and Johnston, C.: 1998, Observations on buried surface hoar in British Columbia, Canada: section analyses of layer evolution, Proc. 1998 Int. Snow Sci. Workshop, Sunriver, Oregon, 86-92.
Fitzharris, B. B.: 1976, An avalanche event in the seasonal snow zone of the Mount Cook region, New Zealand, New Zealand J. of Geol. and Geophys. 19, 449–462.
Fitzharris, B. B.: 1981, Frequency and climatology of major avalanches at Rogers Pass, 1909-1977, National Research Council, Canadian Association Committee on Geotechnical Research, DBR Paper No. 956, 99 pp.
Fitzharris, B. B.: 1987, A climatology of major avalanche winters in western Canada, Atmos.-Ocean 25, 115–136.
Fitzharris, B. B. and Bakkehøi, S.: 1986, A synoptic climatology of major avalanche winters in Norway, J. Climatol. 6, 431–446.
Fitzharris, B. B., Allison, I., Braithwaite, R. J., Bown, J., Föhn, P. M. B., Haeberli, W., Higuchi, K., Kotlyakov, V. M., Prowse, T. D., Rinaldi, C. A., Wadhams, P., Woo, M. K., and Youyu, X.: 1996, The cryosphere: changes and their impacts, in R. Watson, M. Zinyowera, and R. Moss (eds.), Climate Change 1995, impacts, adaptations and mitigation of climate change: scientific-technical analysis, Contribution of Working Group II to the Second Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, UK, pp. 241–266.
Föhn, P. M. B: 1992, Climatic change, snow-cover, and avalanches, Catena Supplement 22, 11–21.
Fredston, J. and Fesler, D.: 1994, Snow Sense - A Guide to Evaluating Avalanche Hazard, Alaska Mountain Safety Center, Anchorage, Alaska, 116 pp.
Frutiger, H.: 1990, Maximum avalanche runout mapping: a case study fromthe central Sierra Nevada, Proc. 1990 Int. Snow Sci. Workshop, Bigfork, Montana, pp. 245–251.
Gürer, I., Tunçel, H., Yavaş, Ø. M., Erenbilge, T., and Sayin, A.: 1995, Snow avalanche incidents in north-western Anatolia, Turkey during December 1992, Natural Hazards 11, 1–16.
Hächler, P.: 1987, Analysis of the weather situations leading to severe and extraordinary avalanche situations, Int. Assoc. of Hydrological Sci. Publ. 162, 295–304.
Höller, P.: 1999, Weather and avalanches in Austria: a brief synopsis of the Austrian Alps, The Avalanche Review 17(6), 10.
Jamieson, B. and Johnston, C.: 1998, Snowpack factors associated with strength changes of buried surface hoar layers, Proc. 1998 Int. Snow Sci. Workshop, Sunriver, Oregon, pp. 74–85.
Judson, A.: 1970, A pilot study of weather, snow, and avalanche reporting for western United States, National Res. Council of Canada Tech. Memo. 98, Ottowa, 123–134.
Klein, W. H. and Bloom, H. J.: 1986, The synoptic climatology of monthly precipitation amounts over the United States during winter in relation to the surrounding 700 hPa height field, in J. Cehak (ed.), Preprints, The Third International Conference on Statistical Climatology, Österreichische Gesellschafte für Meteorologie, pp. 527–534.
LaChapelle, E. R.: 1966, Avalanche forecasting - a modern synthesis, Int. Assoc. of Hydrol. Sci. Publ. 69, 350–356.
Mass, C. F.: 1993, The application of compact discs (CD-ROM) in the atmospheric sciences and related fields: an update, Bull. Amer. Meteor. Soc. 74, 1901–1908.
McCabe, G. L. and Legates, D. R.: 1995, Relationships between 700 hPa height anomalies and 1 April snowpack accumulations in the western U.S.A., Int. J. Climatol. 15, 517–530.
McClung, D. and Schaerer, P.: 1993, The Avalanche Handbook, The Mountaineers, Seattle, Washington, 271 pp.
McNulty, D. and Fitzharris, B. B.: 1980, Winter avalanche activity and weather in a Canterbury alpine basin, New Zealand J. of Geol. and Geophys. 23, 103–111.
Mears, A. I.: 1992, Snow-avalanche hazard analysis for land-use planning and engineering, Colorado Geological Survey Bulletin 49, Colorado Department of Natural Resources, Denver, Colorado, 55 pp.
Meiklejohn, B.: 1986, Regional roundup, The Avalanche Review 4(5), 5.
Mock, C. J.: 1995, Avalanche climatology of the continental zone in the southern Rocky Mountains, Physical Geography 16, 165–187.
Mock, C. J.: 1996a, Avalanche climatology of Alyeska, Alaska, U.S.A., Arctic and Alpine Res. 28, 502–508.
Mock, C. J.: 1996b, Climatic controls and spatial variations of precipitation in the western United States, J. Climate 9, 1111–1125.
Mock, C. J. and Kay, P. A.: 1992, Avalanche climatology of the western United States, with an emphasis on Alta, Utah, The Professional Geographer 44, 307–318.
Mock, C. J. and Birkeland, K. W.: 2000, Snow avalanche climatology of the western United States mountain ranges, Bull. Am. Met. Soc. 81(10), 2367–2392.
Mock, C. J., Birkeland, K. W., and Gress, G. J.: 2000, Snow avalanche climate extremes: two examples in the western United States, in J. G. West and L. Buffaloe (eds), Proceedings of the 16th Annual Pacific Climate (PACLIM) Workshop, Interagency Ecological Program Technical Report, California Department of Water Resources.
Perla, R. I. and Martinelli, M., Jr.: 1978, Avalanche Handbook, U.S. Department of Agriculture Forest Service, Agriculture Handbook 489, 254 pp.
Rangachary, N. and Bandyopadhyay, B. K.: 1987, An analysis of the synoptic weather pattern associated with extensive avalanching in western Himalaya, Int. Assoc. of Hydrol. Sci. Publ. 162, 311–316.
Rayback, S. A.: 1998, A dendrogeomorphological analysis of snow avalanches in the Colorado Front Range, USA, Physical Geography 19(6), 502–515.
Roch, A.: 1949, Report on snow avalanche conditions in the U.S.A. western ski resorts from the 26th of January to the 24th of April, 1949, Eidg. Institut für Schnee und Lawinenforschung Internal Report 174.
Roos, M.: 1996, The top ten California floods of the 20th century, in C. Isaacs and V. Tharp (eds.), Proceedings of the Eleventh Annual Pacific Climate (PACLIM) Workshop, Interagency Ecological Program, Technical Report 40, California Department of Water Resources, pp. 9–18.
Voight, B., Armstrong, B. R., Armstrong, R. L., Bowles, D., Brown, R. L., Ferguson, S. A., Fredston, J., Kiusalaas, J., McFarlane, R. C., and Penniman, R.: 1990, Snow Avalanche Hazards and Mitigation in the United States, National Academy Press, Washington, D.C., 84 pp.
Williams, K.: 1985, November 1985 avalanche notes, U.S. Forest Service Westwide Avalanche Network, Rocky Mountain Forest and Range Experiment Station, 2 pp.
Williams, K.: 1986, February 1986 avalanche notes, U.S. Forest Service Westwide Avalanche Network, Rocky Mountain Forest and Range Experiment Station, 2 pp.
Wilson, N. A.: 1986, A widespread cycle of unusual avalanche events, Proc. 1986 Int. Snow Sci. Workshop, pp. 153–154.
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Birkeland, K.W., Mock, C.J. The Major Snow Avalanche Cycle of February 1986 in the Western United States. Natural Hazards 24, 75–95 (2001). https://doi.org/10.1023/A:1011192619039
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DOI: https://doi.org/10.1023/A:1011192619039