The Use of Satellite-observed Cloud Patterns in Northern Hemisphere 500-mb Numerical Analysis

Book excerpt: A quasi-objective method for deriving 500-mb geopotential heights with the aid of satellite cloud observations is presented. The method uses satellite-observed cloud patterns in conjunction with a forecast 500-mb height field which is separated into additive short- and long-wave component fields. Empirical relationships between the cloud patterns and the short-wave component field are used to modify the pattern of the latter, and regression equations are used to specify extrema values. The 500-mb heights are retrieved by the direct addition of the modified short-wavelength field to the long-wavelength field. Procedures for using this method operationally are presented, and results of real-time modifications can contribute to significant improvements in the analysis.