P redictability AN d D ynamics O f W eather Systems in the A tlantic- E uropean Sector

1. Moist Processes and Diabatic Rossby Waves European Windstorms Severe Convection Upper-level Rossby wave trains: triggering, propagation and wave-breaking High Impact Weather Mediterranean Cyclones Tropical Cyclones Ensembles and Adaptivity Predictability ANd Dynamics Of Weather Systems in the Atlantic-European Sector PANDOWAE DFG Forschergruppe (Research Unit) 896

2. Motivation Mitigation of impact of severe weather requires accurate numerical weather forecasts Accuracy of weather forecasts limited not only by technical factors but also by gaps in our knowledge of the processes involved and their representation in forecast models www.wmo.int/thorpex

3. Motivation PANDOWAE initiative developed directly out of THORPEX Aim of PANDOWAE: “ to advance our knowledge and understanding of the dynamical processes responsible for the development of high impact weather systems, to elucidate the factors that limit the predictability of such systems, and to contribute the basic research that will lead to the development of innovative interactive weather forecasting systems” PANDOWAE aims to carry out basic research with strong societal and economic relevance PANDOWAE is motivated by operational needs but not constrained by them PANDOWAE represents a major contribution to answering some of the fundamental scientific questions posed in THORPEX

4. What is a DFG Research Unit? • DFG guidelines: • medium-sized research group collaborating closely on specific medium-term research project • manageable number of projects that all deal with the same subject and that can only be worked on as a group in the proposed manner • topic is current and relevant, basic concept highly innovative and coherent, justifying six year time-frame • constitutive feature is cooperation between the individual proposed projects • Research Units contribute towards: • providing young scientists with an opportunity to develop their research skills • strengthening cooperation with non-university partners • expanding international cooperation • improving the infrastructure of university-based research

5. PANDOWAE Timeline First Phase 2008-2011: Funding for 3 (+1) Postdocs, 8 (+1) Ph.D. Students Midterm review Autumn 2010 Second Phase 2011-2013

6. Weather Systems 1 day to 2 week weather forecasts

7. 3 Fundamental Research Themes Upper-level Rossby waves: What triggers them? How do they develop as they propagate downstream? What determines their predictability? What is their role in severe weather events? Analysed 500 hPa height anomaly heavy precipitation event time days prior to the event time wave composites (autumn season) 180W 180E Martius, Schwierz and Davies (2007) Elbe flooding

8. 3 Fundamental Research Themes Moist processes and diabatic Rossby waves: How do they influence the evolution of weather systems? What is their role for predictability? How frequent are diabatic Rossby waves? dynamical tropopause (2 pvu) DRW: diabatically produced PV anomaly in lower troposphere „Lothar“: 26. Dezember 1999, 7 UTC Wernli et al. 2002

9. 3 Fundamental Research Themes Adaptivity and Ensembles: What is the value of adaptive observations using different targeting methods? How can uncertainty be represented in ensembles in a flow-dependent way? What insights come from TIGGE for PDP questions? COSMO-LEPS Flow-dependent sampling Verbunt et al. (2007)

10. 3 Fundamental Research Themes Upper-level Rossby waves: What triggers them? How do they develop as they propagate downstream? What determines their predictability? What is their role in severe weather events? Moist processes and diabatic Rossby waves: How do they influence the evolution of weather systems? What is their role for predictability? How frequent are diabatic Rossby waves? Adaptivity and Ensembles: What is the value of adaptive observations using different targeting methods? How can uncertainty be represented in ensembles in a flow-dependent way? What insights come from TIGGE for PDP questions? The THORPEX Interactive Grand Global Ensemble: a multi-model, multi-analysis, multi-national ensemble prediction system

11. PANDOWAE Projects PANDOWAE-Project Office: Aurelia Müller PANDOWAE-ET: Sarah Jones, Doris Anwender, Christian Grams, Julia Keller, Simon Lang PANDOWAE- DIAC: Heini Wernli, Maxi Böttcher, Jana Čampa PANDOWAE-MED: Christoph Kottmeier, Ulli Corsmeier, Claus-Jürgen Lenz PANDOWAE-SESUWAT: Volkmar Wirth, Hartmut Borth (Hamburg), Ilona Türschmann PANDOWAE-VARNAER: Dieter Peters PANDOWAE-ADOBS: Martin Weissmann, Florian Harnisch Link to HALO-THORPEX / T-NAWDEX: Andreas Dörnbrack PANDOWAE- ADENS: George Craig, Pieter Groenemeijer

12. Research Areas • Focus on joint research questions within the research areas • All partners contribute to more than one research area • Significant overlap between the research areas • Enhanced collaboration between partners

13. High Impact Weather PANDOWAE

14. Approach • Research questions will be addressed through: • Climatologies linking dynamical processes to forecast error • Joint case studies based on operational analyses and forecasts / TIGGE data and applying diagnostic techniques • Idealised and real-case modelling studies • Data denial and data impact studies • Application and further development of ensemble systems • Synergy between theoretical studies / analysis of NWP data / numerical modelling / planning and analysis of observational campaigns

15. First results: TTISS Presentations Martin Weissmann et al. (DLR, Germany):Overview of T-PARC Falcon operations and first results from ECMWF data denial experiments Florian Harnisch and Martin Weissmann (DLR):Observation impact of dropsonde Data Christian Grams and Sarah Jones (U. Karlsruhe): The interaction of Typhoon Jangmi (2008) and the midlatitude jet Simon Lang (U. Karlsruhe), Sarah Jones, Martin Leutbecher:The structure of singu- lar vectors associated with extratropical transition of tropical cyclones Doris Anwender (U. Karlsruhe), Sarah Jones, Carla Cardinali: Data denial experiments for extratropical transition Maxi Boettcher and Heini Wernli (U. Mainz): A case study of an explosively deepening, diabatic Rossby-wave induced cyclone: the inuence of environmental conditions Ilona Tuerschmann (U. Mainz): The role of a long-lived Rossby wave train in the Elbe flooding on 10-12th of August 2002. Heini Wernli and Jana Campa (U. Mainz): A climatological analysis of diabatic processes associated with extratropical cyclones Julia Keller (U. Karlsruhe) Sarah Jones and Doris Anwender: Investigation of predictability during the extra-tropical transition of tropical cyclones using TIGGE

16. Collaboration within PANDOWAE • Joint case studies (August – October 2008) • Use of common tools (COSMO Model, ECMWF IFS, Diagnostics, ....) • Analysis of TIGGE data • Workshops • Young Scientists Meetings 9-11 June 2008 Höfen 16-18 Feb 2009 Murnau 6. – 8. July 2009 in Mainz 15. – 17. Dec. 2008 in Karlsruhe

17. External partnerships • Associated Projects: DLR, Leeds, ETH • DWD • ECMWF • THORPEX • Major part of PDP WG programme • Contribution to DAOS WG • Contribution to T-PARC • Contribution to Plan for Europe • Further partners at national and international level

18. www.pandowae.de