Formulation of the Lateral Boundary Conditions for the NCAR Limited-Area Model

Abstract

The Limited-Area Model (LAM) developed at the National Center for Atmospheric Research for use in conjunction with the NCAR Global Circulation Model is described including details of the lateral boundary conditions. One set of experiments is described for which a 2½° glow simulation provides the correct or control data against which 2½° LAM forecasts are compared. Three cases are considered in which the LAM inflow boundary values are provided by the 2½° global forecast, a 5° global forecast, or are held fixed equal to the initial values. Forecasts produced by the LAM with finer gods (up to ?°) are also shown. Although based on simulated data, the results indicate that the Limited-Area Model shows good potential for short-range forecasting.