Joint WGNE,WGSIP,S2S&OMDP session presentations Pan-WCRP Modelling Groups Meeting and the 6th Session of the WCRP Modelling Advisory Council UK Met Office, Exeter, United Kingdom, 9‑13 October 2017 John McCormack: SPARC Report to the Working Group on Numerical Experimentation (WGNE) Oscar Alves, Craig Bishop, John Methven, Judith Berner: PDEF:Probability Dynamics Ensemble Forecasting William Merryfield, Mikhail Tolstykh, Francisco Doblas-Reyes,Tamaki Yasuda, Woo-Sung Lee: Initial Drifts/Shocks: WGSIP’s Long-Range Forecast Transient Intercomparison Project Carla Cardinali,Daryl Kleist, et al.: Data Assimilation & Observing Systems (DAOS)