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 parametrizations which represent subgrid processes inside the atmosphere and interaction processes with its environment. For a long time most NWP models made use of traditional latitude-longitude grids, however, there is an ongoing trend towards quasi-uniform grids derived from platonic solids (icosahedron, cube, etc.). This brings along a lot of benefits, but also some drawbacks that require novel solutions. 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 focus on the above points and to gather presentations and posters on the following topics:
• general aspects of numerical schemes in NWP models;
• issues regarding the coupling between physical parameterizations and dynamics, both in complex GCMs or idealized frameworks;
• variable-resolution modelling (static and/or adaptive mesh refinement);
• the need for scale-aware parameterizations, either due to the recent trend towards variable-resolution modelling, or due to the general need to model the convection and to handle the "grey zone" (transition from synoptic-scale to convective-scale modelling);
• the challenges coming from predicted future changes of computational infrastructure (ever growing need for parallelism, GPUs, Domain Specific Languages, etc.)
• the evaluation, validation, criticism and intercomparison of different numerical and physical schemes.