1. Model error diagnosis: One possible contribution of the PDP community to the THORPEX goals Thomas Jung 1,2 & members of the THORPEX PDP and WGNE & Mark Rodwell 1 European Centre for Medium-Range Weather Forecasts 2 Alfred-Wegener-Institute for Polar and Marine Research (AWI)

2. Outline Model error diagnosis Activities following the PDP/WGNE Workshop on "Diagnosis of Model Errors Extratropical cyclone diagnostics Hand-over to Mark Rodwell

3. What is model error diagnosis? Research that aims at understanding model errors at the process level Research that aids model development What is going wrong (descriptive)? Which regions are crucial (for certain errors)? Which processes are crucial? What is going wrong and how could this be improved? Development of diagnostic techniques Advise model developers Work together with model developers

4. The PDP-WGNE workshop Workshop report available from the THORPEX website!

5. Actions: Model error diagnosis workshop Start joint project on the Indian Summer Monsoon Build on collaboration between ECMWF and UK Met Office Discuss ongoing research in mailing group Report progress in future meetings Start joint project on Cyclonic systems Work on refining existing techniques to understand CS Give presentation entitled Diagnosis of Cyclonic Systems at the cylone workshop in Monterey Both projects Should consider NWP and climate models Benefit from Transpose AMIP activities Develop proposals that can be put forward to WGNE

6. Actions: Model error diagnosis workshop Report workshop results in upcoming meetings 26th session of WGNE (Dave Burride) Cyclone workshop in Monterey (no presentation) AWI/IUP block seminar (T. Jung, model error diagnosis) EGU Vienna 2011 (T. Jung, Relaxation diagnostics in seasonal forecasting) THORPEX European regional meeting (T. Jung, model error diagnosis) WWRP-JSC meeting in late winter 2011 (Mark Rodwell?) Publish workshop report in BAMS Chris Capella from BAMS has been contacted First response (although late) was positive Later Chris became concerned given that the workshop report has been published Chris wanted to tallk to editors (no response yet)

7. Impact: New convection scheme Jung et al. (2010), QJRMS

8. Extratropical cyclone composites Z850 Dynamics VDiff Convection Mean 6-hr wind-tend 925hPa Short-range forecasts (old and new convection) ERA-Interim period Archiving of tendencies Selection of 100 most intense winter storms Compositing Hodges and Jung, work in progress

9. Extratropical cyclone composites: New-old Z850 Convection 6-hr T-Tend Diff Conv 700hPa 6-hr T-Tend Diff Cloud 700hPa Z500 Diff

10. Diagnosis of cyclonic systems Work on producing extratropical cyclone composites for simulated physical processes has started. Composites for mean analysis increments have been produced (interpretation does not seem straightforward collaboration with Mark Rodwell) Produce composites for other quanitities Ensemble spread (see also work by Simon Lang) Observation usage Considerable progress possible

11. Handover to Mark Rodwell

12. Thank you!