83rd Annual

Wednesday, 12 February 2003: 4:45 PM
Wind-Profiler Derived Snow Level Monitoring: California Highway I-80 Donner Summit
Elizabeth J. Carter, Firnspiegel LLC, Kings Beach, CA; and F. M. Ralph, A. B. White, T. S. Dye, and S. N. Goates
Poster PDF (1011.4 kB)
The goal of this operational project is to improve the accuracy of short-term (0-24 hour) snow-level forecasts for winter storms affecting the Sierra Nevada mountains near Donner summit as well as evaluating the potential use of these data in the decision-making process for highway snow operations. Interstate 80 is the major highway that traverses through the Sierra Nevada mountains. Donner summit is the highest point along I-80 in the Sierra. Donner summit receives an average of 409 inches (1,039 cm) of snowfall a year with the least snowiest year in 1881 receiving only 153 inches (389 cm) and the snowiest year in 1938 receiving 819 inches (2,080 cm). Another impact of snow level on the Sierra is of course accurate forecasts for the traveling public and interstate trucking.

Recent advances in wind profiler technology at the Environmental Technology Laboratory (ETL) NOAA have created the capability to monitor the altitude of the snow level in storms approaching and striking the Sierra Nevada mountains. Profilers deployed along the coast and in the western Sierra foothills as part of the PACJET (Pacific Landfalling Jets Experiment) have provided data that is being used to test this concept. Initial impressions are that the coastal observations of snow level can provide information about what the snow level will be 4 to 10 hours later near Donner Summit.

During the 2000-2001 winter season the California Department of Transportation (CalTrans) spent $13 Million dollars on snow removal for the I-80 region of California. An incorrect forecast of snow level (either too high or too low) causes a great loss in money of CalTrans through such things as overtime pay, improper staffing, not enough equipment in the proper road regions. With more accurate timing of event as well as more accurate snow levels CalTrans will be more effective in the amount of staffing they need, where to concentrate their efforts and what resources to use.

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