NWP models have to cover a large spectrum of atmospheric scales, from the global long waves down to kilometric scales. The models are generally built around a “dynamical core” together with several physical parameterizations which represent processes inside the atmosphere and interaction processes with its environment. Operational NWP models are also constrained by real-time requirements, computing resources and the necessity to assimilate observations regularly. Moreover NWP models are systems which are often used for climate modelling and re-analysis.

This session is expected to gather presentations and posters on the following topics:
- general aspects of numerical schemes in NWP models;
- physical parameterizations and their interaction with a dynamical core;
- the challenges coming from the need to model a larger and larger ensemble of scales as well as more and more detailed basic processes;
- the challenges coming from the need to produce efficient models on massively parallel computers;
- the evaluation, validation, criticism and intercomparison of different numerical and physical schemes.