1. European Storm Forecast Experiment A close look at a severe MCS during the Kyrill winter storm over Central Europe Christoph Gatzen, Pieter Groenemeijer, Oscar van der Velde, Jan Hoffmann, Angel Dimitrov, Helge Tuschy, Johannes Dahl

2. European Storm Forecast Experiment Ingredients-based theory 18 Jan 12 Z. 15 Z. 18 Z

3. European Storm Forecast Experiment Ingredients-based theory 18 Jan 12 Z. 15 Z. 18 Z ?

4. European Storm Forecast Experiment Estofex discussion: Ahead of the cold front… Instability Neutral/slightly moist-unstable lapse rates and rich low-level moisture At least minimal, but positive CAPE, even at low levels Forcing Strong QG forcing, low-level convergence, initiation along cold front Shear Strong vertical wind shear, favorable veering (SRH 0-1km ~800 J/kg) Expected Scenarios 1.Weak instability: Strongly-forced convective line along the cold front moving eastward. High winds the main threat, tornadoes possible 1.Significant CAPE: Well-developed MCS, cold pool and associated low level jets. Extremely high wind gusts at the leading gust front, tornadoes possible

5. European Storm Forecast Experiment Estofex discussion: Ahead of the cold front… Instability Neutral/slightly moist-unstable lapse rates and rich low-level moisture At least minimal, but positive CAPE, even at low levels Forcing Strong QG forcing, low-level convergence Shear Strong vertical wind shear, favorable veering (SRH 0-1km ~800 J/kg) Expected Scenarios 1.Weak instability: Strongly-forced convective line along the cold front moving eastward. High winds the main threat, tornadoes possible 1.Significant CAPE: Well-developed MCS, cold pool and associated low level jets. Extremely high wind gusts at the leading gust front, tornadoes possible

6. European Storm Forecast Experiment The Kyrill Storm: Satellite view Hourly images: 18 Jan 08 Z. 19 Jan 00 Z MSG WV6.2-WV7.3 IR9.7-IR10.8 WV6.2i copyright 2007 EUMETSAT

7. European Storm Forecast Experiment Associated MCS: Lightning copyright 2007 EUMETSAT© DWD/Siemens AG 2007 15, 16, 17, 19 Z

8. European Storm Forecast Experiment Associated MCS: Radar composit copyright 2007 EUMETSAT© DWD 2007 12 - 20 Z, radar ¼-hourly

9. European Storm Forecast Experiment Associated MCS: Radar composit copyright 2007 EUMETSAT© DWD 2007 18 Z

10. European Storm Forecast Experiment Associated MCS: Cold pool evolution LMK, surface observations © DWD 2007 16 - 20 Z

11. European Storm Forecast Experiment How did instability develop?

12. European Storm Forecast Experiment High low-level winds ahead of the front LMK – Analysis 800 hPa winds at 18 Z Windprofiler Bayreuth, 14-23 Z

13. European Storm Forecast Experiment Tornado occurrence over Germany Berlin Dresden Tornados occurred at the eastern flank of the cold pool, where low-level winds likely shifted towards the south strengthen of low-level veering increase of low-level convergence also increase of instability due to cool westerly flow overspreading the warm air mass as LMK suggests

14. European Storm Forecast Experiment Tornado occurrence over Germany Berlin Dresden

15. European Storm Forecast Experiment Doppler radar observations: Berlin

16. European Storm Forecast Experiment Cloud radar observations: Lindenberg

17. European Storm Forecast Experiment Doppler radar observations: Dresden

18. European Storm Forecast Experiment Vertical cross section

19. European Storm Forecast Experiment The tornadic supercell near Lauchhammer WER

20. European Storm Forecast Experiment The tornadic supercell near Lauchhammer

21. European Storm Forecast Experiment The tornadic supercell near Lauchhammer

22. European Storm Forecast Experiment The tornadic supercell near Lauchhammer

23. European Storm Forecast Experiment The tornadic supercell near Lauchhammer

24. European Storm Forecast Experiment Thanks! copyright 2007 EUMETSAT© DWD 2007 12 - 20 Z, radar ¼-hourly