This session will focus on the dynamics and predictability of weather systems at lead times up to a few days ahead, as well as some physical processes affecting these systems. The atmospheric systems which generate high impact weather will receive a special attention. The session will accept papers on a wide range of topics that include the following:

- Study of the dynamics of fronts, jet-streams, cyclogeneses, tropical and mid-latitude cyclones.
- Study of processes generating convective events, including (e.g.) stationary convective bands due to orography.
- Theoretical, modelling and observational studies of the dynamical sequence of events that result in well, but also poorly predicted high impact weather events (e.g. : Mediterranean precipitation events).
- Investigations into the dynamical and physical factors that limit the skill of current predictions (e. g. : moist processes in synoptic-scale and convective scale event).

Case studies coming from the operational experience of forecasters and / or field experiments (such as HYMEX or DIAMET) are welcome. These case studies may also use the tools developed for a specific downstream application of NWP forecasts (hydrology, risk of floods, of icing,etc...).