High Impact Weather Emerging challenge identified at CASXVI Mariane DIOP KANE Mariane DIOP KANE CASMG9, Geneva, April 2014

I. Recap of PRECAS 1.High impact weather project by S. Jones  few examples of high impact weather related to urban floods  Achievements of thorpex: Major international field programs, TIGGE Operational EPS data used by research community, YOTC Increased knowledge of processes and predictability associated with High Impact Weather Events Improved forecasts for such events on synoptic scales from days to about two weeks Advanced research on global observing and data assimilation systems and of adaptive observations (Campaigns, DTS) Fostered research on EPS and their usage Enhanced cooperation between operational and academic research communities First attempt to socio ‐ economic research applications (SERA)

CASMG9, Geneva, April 2014  what thorpex did not do address shorter time ‐ and space scales important for impact of severe weather events investigate role of model errors and nonlinear error growth focus on verification consider how to link High Impact Weather events to hazards consider how to meet requirements for applications investigate how to cover future needs of WMO members under processes of urbanisation or a changing climate

CASMG9, Geneva, April 2014 Need to capitalise on these advances New project Objective: “Promote cooperative international research to achieve a dramatic increase in resilience to high impact weather, worldwide, through improving forecasts for timescales of minutes to two weeks and enhancing their communication and utility in social, economic and environmental applications”

CASMG9, Geneva, April 2014 Benefit: Shaped by needs for applications, assessed through communication and interaction with stakeholders Focus on future needs of WMO members for decreasing vulnerability to High Impact Weather by considering urbanisation, increasing population, demographic changes, …….. Incorporate and foster advances in new predictive capability (e.g. cloud resolving ensembles) Focus on predictive time scales of minutes to two ‐ weeks, build upon THORPEX to improve warnings on High Impact weather events

CASMG9, Geneva, April W. Lang adressed the challenges for forecasters in the 21st century in a changing climate, risks and media with too much data 3.Lake Victoria projects and SWFDP by P. Maniha 4 components: - nowcast system, - SWFDP, - field project - capacity building interconnected with 3 WMO entities - SWFDP recommended by EC - HYVIC, a GEWEX hydroclimate project - WWRP lake Victoria

CASMG9, Geneva, April 2014

II. CAS summary/recommendations 1.Accelerated and focused research required especially at local scales 2.WWRP to coordinate the activities with WCRP, GFCS, relevant commissions, regional associations and appropriate WMO prog 3.WWRP and WCRP to prepare scientific studies on the impact of CC on high impact weather events 4.High priority to research into realizing the potential of coupled systems with appropriate observational capability for initialisation 5.WWRP to contribute to developing user oriented verification indices for high imapcts weather events 6.Draft of High Impact HIWeather project as post-Thorpex legacy 7.Importance to involve operational forecasters in the HIWeather project and predicting hydrological consequences

CASMG9, Geneva, April WWRP to promote research in the prediction of the societal impacts of the high impacts weather events 9.WWRP to refine the HIWeather project to ensure that - members needs are fully considered - the link with DRR is strong - cooperation between the academic and the operational community continues - the project is established in a similar manner as PPP and S2S with a resolution to establish a trust fund and an internatinal coordination office 10. members requested to support the project and make expertise and resources available to effectively develop and implement the project

CASMG9, Geneva, April 2014 III. CAS recommendations 1.Post-THORPEX activities  the working group on data assimilation and observing systems and the working on Predictability, dynamics and ensemble forecasting be established beginning 2015 under WWRP and funded on regular basis  the activities of the current THORPEX regional committees be continued under WWRP after the end of THORPEX, if the participating regional members decide to continue on a self- organizing and self-funded basis, in collaboration with the regional associations, the WWRP working groups and projects, including the three THORPEX legacy projects, research and development projects and forecast demonstration projects

CASMG9, Geneva, April 2014  THORPEX legacy projects work together to - to coordinate the respective roles of the projects in areas of common interest and - to share the results, techniques and accomplishments of the projects  the executive management oversight of the THORPEX legacy project trust funds be provided by the CAS MG