Initialization of a limited area model: a comparison between the nonlinear normal mode and bounded derivative methods

A nonlinear normal mode initialization method is applied to a baroclinic limited-area forecast model. This method is very effective in reducing the amplitude of the rapid oscillations during the first hours of the forecast. The results are compared with those obtained by using a bounded derivative initialization. The latter method gives equally satisfactory results, and requires less computation than the normal mode method.