1. Slide 1 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 T-NAWDEX THORPEX- North Atlantic Waveguide and Downstream Impact Experiment proposed by the working group Predictability and Dynamical Processes for the European THORPEX Science Plan suggested to be performed in 2011/2012 in conjunction with HYMEX address the triggering of waveguide disturbances by different processes and the disturbances’ subsequent downstream evolution study of the downstream impacts of the waveguide disturbances over Europe, the Mediterranean, and northern Africa

2. Slide 2 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 PV@320K on January 16, 2002 Model - Analysis Model FC96 Analysis Marco Didone, ETH Zürich courtesy of H. Davies Marco Didone, ETH Zürich courtesy of H. Davies T-NAWDEX: Forecast Errors

3. Slide 3 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 T-NAWDEX: Forecast Errors PV distribution “Fcst-Analysis” field at 320 K. for a 72hrs forecast to 10 Oct. 2001 (ECMWF IFS T511 model). 2pvu isoline: analysis, forecast Pertinent questions: (i)Is the difference pattern typical, and does it persist in today’s upgraded prediction suites? (ii)Is the analysis field itself likely to be inadequate? (iii)Is the difference dynamically significant and/or operationally important? (iv) What is the causes of the difference ? (v) How can it be rectified ? (courtesy of Huw Davies)

4. Slide 4 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 For a specific forecast time the fields have a similar spatial structure Systematic difference in representing synoptic development FC96 FC48FC72 Marco Didone, ETH Zürich courtesy of H. Davies “Forecast -Analysis” fields for forecasts of different time-spans

5. Slide 5 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 Heavy precipitation events on the Alpine south-side Distinctive mesoscale topography Events of Alpine heavy precipitation Downstream wave-breaking resulting in a PV-streamer - 6d - 12d 180 W180 E Event Composite of preceeding Hovmöller trace Olivia Martius, Alexia Massacancd, ETH Zürich

6. Slide 6 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 MODIS (Aqua) 14:55 UTC 24 November 2003 Greenland Tip Jet - Wind Lidar observation FL200 z~6.0 km

7. Slide 7 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 Horizontal Wind Speed - Wind Lidar (One Scanner Revolution) North South

8. Slide 8 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 North South Horizontal Wind Speed -  LIDAR-ECMWF

9. Slide 9 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 Question (ii):Is the analysis field itself likely to be inadequate ? PV distribution on 310 K surface Error > 15 m/s Wind speed Wind direction Flight altitude & height of 310K surface Aircraft measurements ECMWF NCEP ? Sandro Buss,ETH Zürich courtesy of H. Davies

10. Slide 10 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 Errors in medium range forecasts for Europe mainly due to a small number of 'busts', e. g. from ET, DRW (Cardinali/Buizza) There are systematic patterns of forecast errors in extratropical cyclones, e. g. the downstream side of the trough in developing cyclones should be sharper (Davies) Are these deviations potentially associated with latent heat release, the most poorly understood/modelled part of the dynamics? Kilometer-resolution models appear to dramatically better, at least at short range (MAP D-PHASE), but need to be evaluated for THORPEX timescales Comparison with research aircraft shows even analysis faulty (resolution and/or diabatic effects?), so research measurements required Advanced observing technologies, (air-, spaceborne platforms, active/passive remote sensing, in-situ sensors,...) are now well- established and can be deployed Motivation for T-NAWDEX

11. Slide 11 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 Triggering of waveguide disturbances by different processes Subsequent downstream evolution of the disturbances, esp. diabatic effects Downstream impacts of the waveguide disturbances over Europe, the Mediterranean and northern Africa. e.g. cooperation with HYMEX Scientific Objects of T-NAWDEX

12. Slide 12 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 T-NAWDEX Planning (1) Use HALO-Demonstration Mission HALO-THORPEX as nucleus for field phase Savannah, Georgia, USA October, 22 2008

13. Slide 13 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 Aims of HALO-THORPEX - demonstrate the possibility of simultaneous airborne remote sensing observations of wind, water vapor and temperature from the lower stratosphere to the boundary layer - investigate the three-dimensional water vapor field and dynamical structures of streamers and their relationship to extreme precipitation events - perform HALO flights to test targeting observing strategies to improve the predictive skill of high-impact weather events over Europe

14. Slide 14 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 T-NAWDEX Planning (2) Workshop 19/20 February 2009 in Erding/Germany (close to MUC) (a) Formulation of the Science Plan - scientific aims and questions - methods to address the questions (theoretical, numerical, experimental) - responsible persons (b) Implementation Plan (c) National/International Cooperation and fund raising

15. Slide 15 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008

16. Slide 16 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008

17. Slide 17 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 HALO-THORPEX Andreas Dörnbrack, Gerhard Ehret, Ulrich Schumann DLR Oberpfaffenhofen Volker Wulfmeyer, Andreas Behrendt, Hans-Stefan Bauer Universität Hohenheim Sarah Jones Universität Karlsruhe/Forschungszentrum Karlsruhe A 50 h Demonstration Mission of the German HALO Aircraft planned for autumn 2010 or 2011

18. Slide 18 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 Instruments - 1.6  m scanning Doppler Wind Lidar (DLR, IPA) - 4 wavelength water vapor DIAL (DLR, IPA) - Basic Meteorology (DLR, FB) - Dropwinde sondes (DLR, Uni/FZ Karlsruhe) - Microwave Temperature Profiler (DLR) - Scanning rotational Raman Lidar (Uni Hohenheim)

19. Slide 19 7th Session of the THORPEX International Core Steering Committee WMO Headquarters, Geneva, 19 November 2008 THORPEX interest for HYMEX T-NAWDEX - upstream conditions, global models, TIGGE, observing strategies international meteorological links: Europe, North America, Africa HYMEX interest for THORPEX HYMEX - mesoscale and local measurements, high resolution modeling and data assimilation SERA - end to end trial, hydrology, end users THORPEX-HYMEX Links