The scientific challenges.
The main scientific challenges for future global NWP relate to the main themes that have produced key advances in the recent past and that have brought weather forecasting to the level where it is today: physical process parameterization, analysis and forecast uncertainty formulation through ensembles, and the provision of physically consistent initial conditions for forecasts using observations. There are a number of key areas in which substantial progress can be expected in the future that also require significant advances compared to current thinking.