The Met Office is due to implement new operational global and mesoscale forecast models, during the first half of 2002. The new model, commonly referred to as the 'New Dynamics', includes major changes to both the physics and dynamics. It is non-hydrostatic and has a semi-lagrangian advection scheme. There are new formulations for many of the parameterization schemes as well as other changes including increasing the vertical resolution from 30 to 38 levels.

The new model configuration has been undergoing comprehensive acceptance trials comparing its performance against the current operational model. In the Northern Hemisphere, RMS errors verified against observations have been improved by up to 5%, in all seasons. Systematic biases have been reduced and there is evidence which shows extreme event forecasting has improved.

This paper will present the trials results and report on the model's implementation.