Accession Number : AD0286286

Title :   Baroclinic Forecasts with Unfiltered 5-Layer Model.

Corporate Author : DEUTSCHER WETTERDIENST AACHEN (WEST GERMANY)

Report Date : 31 MAY 1962

Pagination or Media Count : 1

Abstract : The numerical weather prediction group of the German weather service started experiments with an unfiltered 5-layer model using actual weather situations as initial data. In these computations horizontal gradients were approximated by finite differences in the conventional way; the lateral boundary condition was simplified (vanishing normal and tangential component). Though applying considerable horizontal smoothing, it was not possible to suppress an unstable amplification of the short wave-lengths for forecast periods longer than 48 hours. As the conventional finite difference approximation of horizontal pressure gradients is affected by serious defects encountered in the short wave-length range (between 2 and 4 grid increments) a new finite difference scheme was derived. (Author)

Descriptors :   *ATMOSPHERE MODELS, *WEATHER FORECASTING, BAROMETRIC PRESSURE, DIFFERENCE EQUATIONS, METEOROLOGICAL CHARTS, NORTHERN HEMISPHERE

Distribution Statement : APPROVED FOR PUBLIC RELEASE