Tests of a Fine-Mesh Model over Europe and the United States

Abstract

Abstract Thirty–two 24 h forecasts have been run over western Europe and the eastern United States using a six-layer, 60 km mesh primitive equation model. The forecasts show considerable skill in forecasting cyclogenesis over the Mediterranean and the United States in spite of the inadvertent neglect of surface friction over half of the domain. The average 24 h S 1score for sea level pressure is 39.1 compared to an average of 45.9 for Fleet Numerical Weather Central's operational model and 73.4 for persistence. The initialization scheme is based on an objective analysis of the horizontal wind field. Following the wind analysis, we infer geopotential and temperature from the rotational part of the wind with a nonlinear form of the balance equation. We present detailed results from one initial analysis and error statistics from 30 analyses occurring from December 1977 through April 1978. Typical root-mean-square (rms) differences between first-guess and balanced analyses of geopotential and temperature are ...