Numerical Forecasts of Stratospheric Warming Events during the Winter of 1979

Abstract

The predictability of the stratospheric warming events during the winter of 1979 is investigated by performing a series of 10-day forecasts using the UCLA general circulation model. In general, those events are predictable from several days in advance. The accuracy of the prediction, however, can be sensitive to the starting date and such model characteristics as the horizontal resolution. This sensitivity seems to arise because relatively small errors in the predicted tropospheric zonal mean wind can produce large differences in the characteristics of upward wave propagation and thereby large errors in the stratospheric forecast.