Components of atmospheric models used for numerical weather prediction over days, months, seasons and decades

Numerical weather prediction models are the tools used to provide the daily short-range weather forecasts issued to the public in the media.
However, most numerical weather centres run a range of models covering timescales from days to many months. These models may be global in
extent, or may only cover a local region. Due to computing resourcelimitations, even regional-scale models solve the equations of motions of a grid of points too coarse to resolve all processes and scales of motions that are of relevance. These have to be represented by
simplified models, or parametrizations. One example is convective and cloud processes which will be discussed. This talks will give an
overview of the components of models used from daily to seasonal tiemscales and beyond, highlighting some differences and similarities.
The systems of the European Centre for Medium Range Weather Forecasts will be used as an example. Active areas and outstanding questions
concerning future NWP model development will be raised.