Assessment of Indirect Fatalities from Winter Precipitation

Winter precipitation poses a threat to life and property across the United States. Fatalities from winter precipitation can be classified as either direct or indirect. Direct fatalities occur when the winter precipitation was a direct agent in the death, as in the case of a fatal slip and fall or an avalanche. Indirect fatalities occur when the winter precipitation contributes to the fatal event, with vehicle accidents and carbon monoxide (CO) poisoning among the biggest killers. The distinction between direct and indirect fatalities is important as indirect fatalities are not included in Storm Data, the primary source of information on weather fatalities used by meteorologists. Previous studies have estimated that winter precipitation is responsible for 40-70 fatalities per year; however these studies have only examined direct fatalities and have excluded indirect fatalities. This study seeks to explore the spatial and temporal characteristics of indirect winter precipitation fatalities. Multiple sources were used to gather information on indirect fatalities. Vehicle fatalities were obtained from the Fatality Analysis Reporting System (FARS) administered by the National Highway Traffic Safety Administration (NHTSA), and from records of the National Transportation Safety Board (NTSB). CO poisoning fatalities were primarily compiled from Centers for Disease Control and Prevention (CDC) datasets, news accounts, and some limited information available in Storm Data. Both vehicle and CO fatalities were analyzed in aggregate and also normalized by number of events and population to reveal underlying patterns of mortality. The addition of data on indirect fatalities to existing knowledge of direct fatalities will result in a more complete understanding of the hazards posed by winter weather.