Baroclinic Forecasts with Unfiltered 5-Layer Model.
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 31, 1962
- Accession Number
- AD0286286