An Improved Fuzzy Logic System For Automated Short Term Aviation Weather Forecasts

The Federal Aviation Administration (FAA) aviation weather policy has emphasized the need for accurate and timely predictions of the onset, severity, and dissipation of low ceilings and visibility conditions in the airport terminal area. FAA studies have also identified the need for graphical forecast products that are focused on the 0-8 hour time period. Harris Corporation, provider of WARP and OASIS weather processing systems for the FAA, has a fuzzy logic based forecast system for short term ceiling and visibility forecasts that has demonstrated significant skill over a verification period of almost four years. Recent improvements in this forecast system have led to ceiling and visibility forecasts for Instrument Flight Rule (IFR) conditions that have demonstrated consistent improvement over persistence and have outperformed official National Weather Service forecasts for IFR conditions as well. The forecasts are based on fuzzy systems utilizing multiple numerical weather forecast models and current surface conditions as inputs.

The fuzzy logic forecast system produces automated ceiling, visibility, wind and weather forecasts for 1344 terminal locations in the continental United States. Forecasts, both textual and graphical, are generated upon arrival of each new surface observation (METAR) and are therefore always current. This paper describes improvements to the Harris short-term aviation forecast system and provides detailed verification statistics that show its performance relative to other guidance and official forecast products. The paper will also briefly discuss how this tool fits into other aviation-related initiatives at Harris.