Accurate contrail forecasts allow pilots to avoid levels of the atmosphere that are conducive to contrail formation, reducing their likelihood of being visually detected by enemy forces. The primary object of this research was to evaluate the performance of the JETRAX contrail forecast algorithm currently used the Air Force Weather Agency to support military air operations.
A total of 397 ground-based observations were collected at Wright-Patterson Air Force Base (WPAFB) on 27 different days in the Fall of 1997. Observations were collected with the aid of the WPAFB air traffic control radar, which greatly facilitated the positive identification of overflying aircraft and provided necessary information such as aircraft type and flight level. This data set was used to validate corresponding contrail forecasts disseminated to operational users via the Air Force Weather Information Network (AFWIN).
Contrail forecasts produced with the JETRAX algorithm used assumed relative humidities of 40% from 300 mb level to 300 meters below the tropopause, 70% within 300 meters of the tropopause, and 10% at altitudes 300 meters above the tropopause and higher. For comparison, 333 contrail forecasts were produced using flight level relative humidities obtained with high-resolution radiosondes within 2 hours of aircraft observation. All forecast products derived using assumed relative humidities demonstrated greater skill than persistence, climatology, or other algorithms tested with real-time radiosonde data
The 8th Conference on Aviation, Range, and Aerospace Meteorology