The cloud top pressure product is derived hourly from the CO2 sensitive channels on the Geostationary Operational Environmental Satellite (GOES) Sounder. Since 29 October 1999, these products have been produced operationally by the National Environmental Satellite Data and Information Service (NESDIS). The area of coverage is approximately 20 N to 50 N and 60 W to 160 W, which corresponds to the continental United States and the surrounding waters. A workstation version of the National Center for Environmental Prediction's (NCEP) 48Km Eta Data Assimilation System (EDAS) was used for this study. The cloud water mass was adjusted or "nudged" into the EDAS during the 3-hour model runs between 3-D Variational Analysis (3DVAR) cycles. At each cloud physics timestep (480 sec.) during the model integration the cloud water mass was removed down to the derived cloud top pressure level. Cloud water mass was then added at the cloud top pressure if none was present.

Parallel Eta forecast runs between the control Eta simulation without the cloud top pressure product and simulations with the cloud top pressure product will be presented and compared to satellite images.