FORECASTING APPLICATIONS OF HIGH-RESOLUTION SATELLITE CLOUD COMPOSITECLIMATOLOGIES

In this paper, the authors describe experimental forecasting tools dev eloped from high-resolution satellite cloud composites. The satellite data were extracted from the new 5-km, hourly, global satellite databa se called Climatological and Historical Analysis of Clouds for Environ mental Simulations (CHANCES). Analysis was focused on a region over th e former Yugoslavia and Adriatic Sea during summer 1994. Cloud composi te images were constructed using digital infrared data for each hour o f the day. The value at each pixel in the cloud composites was the fra ctional coverage of cloud at that location for the season and represen ted its systematic variation. Composite images were also constructed f or conditional probabilities of cloud 1-12 h past each hour of the day . The values at any particular pixel in the composites represented the conditional probability of cloud given an initial condition of cloudy or clear in that pixel. Data from both types of composite images were combined to produce a climatological forecasting tool. Forecast table s were constructed of values for the pixel centered over Sarajevo. The se tables are similar to the conditional climatology statistics famili ar to forecasters in any weather station. A more sophisticated type of conditional probability was rested in which the initial condition was dependent on the average conditions of a region of pixels surrounding the Sarajevo pixel. Results demonstrate powerful operational applicat ions of high-resolution satellite cloud climatologies.