Expanding the Road Weather Information System for Avalanche Support

Abstract

Transportation agencies use road weather information systems to support operations, maintenance, and informed travel decisions. Road weather capabilities have been expanded through the FHWA Weather Responsive Traffic Management’s advisory, control, and treatment strategies to address weather-related roadway impacts. Monitoring conditions that precede avalanches offers a new opportunity to leverage the road weather information system’s infrastructure. Wet avalanches, particularly wet slab avalanches, pose considerable risk. They can occur simultaneously across an extensive area, encompass a greater mass of material, create considerable energy, cause significant road closures, and lead to major injuries and fatalities. Roadside and at-altitude avalanche indicators can be monitored by adding sensors to existing road weather environmental sensor stations, deploying new environmental sensor stations at both roadside and at-altitude locations, and creating new, collaborative partnerships. The traditional sensor suite of the road weather information system can be augmented with new meteorological and snowpack sensors to monitor preavalanche conditions. Calibrated present weather detector sensors and heated precipitation gauges can provide improved estimates of the precipitation’s liquid water equivalent. Thermistor strings and lysimeters can provide snowpack stability evaluations. Adding environmental sensor stations, both at roadside and at altitude, can provide strategic observations of the atmospheric and snowpack conditions. Increased coordination between agencies on site selection, sensor choices, and data distribution can expand the role of road weather information systems to support avalanche forecasting.