The Impact of Satellite Soundings on the Numerical Forecasts of the Israel Meteorological Service

Abstract

Experiments with the numerical models of the Israel Meteorological Service show that the impact of satellite soundings can be substantial but depends on how the soundings are used by the models. The quasi-optimum use of satellite data in defining a first guess for the hemispheric analyses results in average reductions of error of up to 20% for 48-h predictions of sea level pressure and 10% for 500 mb height. The greatest average impact occurs at low levels in the atmosphere over the ocean near where the satellite data are introduced. Impact for individual cases tends to be large and concentrated near important synoptic features such as lows, but small elsewhere.