Recent Development of The Generalized Cloud Analysis Package In Gridpoint Statistical Interpolation For The Rapid Refresh

Abstract

A generalized cloud analysis package with both stable and convective cloud modules has been developed and integrated into the Gridpoint Statistical Interpolation (GSI) analysis software. This cloud analysis package has been used at ESRL/GSD in real-time testing within the Rapid Refresh (RR) regional assimilation systems, which is planned to replace RUC for operation in 2010. Within RR, the cloud analysis package utilizes NESDIS GOES satellite-derived cloud top pressure and temperature data, surface METAR multi-level cloud and visibility information, as well as radar reflectivity data, to determine the cloud and precipitation distribution, hydrometeor mixing ratios, and the temperature tendency within convective systems. To extend cloud observation coverage in RR domain, additional data sets, including lightning and satellite-derived liquid and ice water path products, are being tested. The liquid and ice water path fields are derived by the NASA Langley Research Center in real-time utilizing multiple GOES channels. We will provide a brief overview of the cloud analysis system, then describe the specific procedures for using the various satellite fields and merging the information from the different data sources with the hourly cycled model cloud and hydrometeor fields. We will then illustrate the impact of these various data sources on the RR analysis and forecast fields, with particular focus on the use of the NASA Langley experimental water and ice path fields. Finally, we will discuss plans for evolving the current cloud analysis procedure into a variational hydrometeor analysis integrated within GSI.