Meteorological Applications of WVSS-II Water Vapor Data from Commercial Aircraft
The National Weather Service has collaborated with United Parcel Service and Southwest Airlines to collect water vapor data from over 120 aircraft equipped with the Water Vapor Sensing System version 2 (WVSS-II). WVSS-II data are a subset of aircraft meteorological data known as AMDAR (Aircraft Meteorological Data Report) that are collected from over 3,000 commercial aircraft around the world. AMDAR data are currently used by national meteorological centers as input to numerical weather prediction models, and directly by meteorologists to improve forecasts and warnings.
Despite being a relatively new source of atmospheric moisture data, meteorologists at National Weather Service Forecast Offices and national centers have found many applications of these data to improve forecasts and advisories. These include improved forecasts of convective initiation or inhibition, formation of low clouds and fog, aircraft icing, and precipitation type of winter storms.
The author(s) will first present a short historical discussion of efforts to collect water vapor data from commercial aircraft, including WVSS-I, TAMDAR, and WVSS-II. Several case studies will then follow that show WVSS-II sounding information, NWS Area Forecast Discussions that explain how the water vapor information was used in forecast decisions, and the observed weather that verified those forecast decisions. Finally, future plans to expand the number of aircraft collecting water vapor data will be discussed, as well as possible future applications of WVSS-II data.