Boundary Conditions for Fine-Mesh Limited-Area Forecasts

Abstract

A fine-mesh, limited-area, nondivergent barotropic forecast is initialized with fine-scale wind data with time-variant lateral boundary conditions derived from a large-scale, coarse-mesh forecast. Undesirable instabilities develop in the vicinity of the outflow boundaries of the fine-mesh region. A numerical technique which eliminates these instabilities is presented and tested.