Abstract: An iterative method is presented to determine perturbations that maintain their growth rate in the medium-range period. In order to study the efficiency of this approach, experiments are performed with a three-level ...

Abstract: Two experiments are performed to predict the regional forecast skill over western Europe using a three-level quasigeostrophic model with truncation T21 (T21QG). The predictor of skill, the maximal forecast error over the ...

Abstract: The sensitivity of the onset of two weather regimes with respect to initial conditions is studied. The weather regimes are a Euro?Atlantic blocking regime and a Euro?Atlantic strong zonal flow regime. Both regimes are ...

Abstract: The sensitivity of the wintertime tropospheric circulation to changes in the strength of the Northern Hemisphere stratospheric polar vortex is studied using one of the latest versions of the ECMWF model. Three sets of ...