APPLICATION OF GOES-8 9 SOUNDINGS TO WEATHER FORECASTING AND NOWCASTING/

Since April 1994 a new generation of geostationary sounders has been m easuring atmospheric radiances in 18 infrared spectral bands and thus providing the capability for investigating oceanographic and meteorolo gical phenomena that far exceed those available from the previous gene ration of Geostationary Operational Environmental Satellites (GOES). M enzel and Purdom foreshadowed many of the anticipated improvements fro m the GOES-8/9 sounders. This article presents some of the realization s; it details the in-flight performance of the sounder, presents both validated operational. as well as routinely available experimental pro ducts, and shows the impact on nowcasting and forecasting activities. For the first time operational hourly sounding products over North Ame rica and adjacent oceans are now possible with the GOES-8/9 sounders. The GOES-8/9 sounders are making significant contributions by depictin g moisture changes for numerical weather prediction models over the co ntinental United States, monitoring winds over oceans, and supplementi ng the National Weather Service's Automated Surface Observing System w ith upper-level cloud information. Validation of many sounding product s has been accomplished by comparison with radiosondes and aircraft me asurements. Considerable progress has been made toward assimilation of soundings from clear skies and cloud properties in cloudy regions in operational as well as research forecast models; GOES-8/9 moisture sou ndings are now being used in the operational Eta regional forecast mod el.