Correlation between Observed Snowfall and Operational Efficiency at Major U.S. Airports

As the volume of air traffic operations at major US airports increases, significant weather events have an increasing effect on safety, commerce, and the overall operational efficiency of the National Airspace System (NAS). In addition, each airport has a varied impact given a similar weather event making efficient planning all the more difficult. This study examines the impact of observed snow events (one or two inches in a calendar day based on location) during peak operational hours on the total number of air Instrument Flight Rule (IFR) operations at Core 30 airports. Additional parameters used to define a snow event include local time of day in which snowfall occurred, snow intensity, visibility, predominant precipitation types, and impacts from prior day large weather events. The period of study is 2007-2017, and operational efficiency is based on historical FAA Operations and Performance Data. The result is a graph with snow events versus percent of normal operations for each airport. This includes a best-fit curve to provide operational decision makers in airline, airport, and air traffic operations with an intuitive graphical tool to maximize operational efficiency for forecasted snow events. Initial results for a small set of 2018-snowfall events demonstrated skill in predicting the number of IFR operations for both forecasted and observed snowfall events. This Impact Based Decision Support Services (IDSS) tool has diverse utility from aviation partners to National Weather Service Weather Forecast Office (WFO) and Center Weather Service Unit (CWSU) forecasters to correlate forecast snowfall to NAS impacts.