In an effort to better characterize the four-dimensional distribution of water in the atmosphere with a view toward improving our understanding of its impact on deep convection, the International H2O Project (IHOP-2002) field experiment will take place over the Southern Great Plains from 13 May to 25 June 2002. The four focus areas of IHOP are: 1) quantitative precipitation forecasting (QPF), 2) convective initiation, 3) atmospheric boundary layer processes and 4) instrumentation research.

CAPS is a participant in IHOP, with a focus on the optimal utilization and impact of water vapor and other high resolution observations in storm-scale QPF. To support the real time operations of IHOP and to obtain an initial assessment of the model performance for the IHOP cases, CAPS will run its Advanced Regional Prediction System (ARPS) in real time at 18, 6 and 2 km resolutions in large nested domains (512x512 points for 2 km grid) during the entire field campaign. The unique aspect of this work is the use of broadband, Level-II data from a network of radars through the Collaborative Radar Acquisition Field Test (CRAFT) project. The ADAS (ARPS Data Analysis System) cloud analysis procedure to be used and the processing of the radar data will be described. The details of forecast configurations and an sample forecast will be given in the extended abstract. More detailed verification statistics and analysis will be presented at the conference.