1. October 2007

2. Why this Upper-Level Low? Not an especially severe weather system (near Ireland) Behaviour was a little unusual Surface charts would give you no clue to the evolution Demonstrates the value of some of the Meteosat Second Generation Imagery

3. Hand-drawn Surface Charts from the Met Eireann Central Analysis and Forecast Office

4. 12Z October 7 th

5. 00Z October 8 th

6. 12Z October 8 th

7. 00Z October 9 th

8. 12Z October 9 th

9. 00Z October 10 th

10. 12Z October 10 th

11. 00Z October 11 th

12. 12Z October 11 th

13. 00Z October 12 th

14. 12Z October 12 th

15. 00Z October 13 th

16. 12Z October 13 th

17. 00Z October 14 th

18. 12Z October 14 th

19. 00Z October 15 th

20. WV Imagery 00Z 7 th Oct to 00Z 15 th Oct

21. RGB Image from MSG – 00Z October 8 th

22. RGB Image from MSG – 12Z October 8 th

23. CROSS-SECTION

24. PV at 12Z October 8 th

25. Relative Humidity at 12Z October 8 th

26. Consequences over Ireland Some very heavy showers in the north and north-east some time after the passage of the cold front. Isolated thunderstorms A quickly-moving feature, so convection rapidly died down, as system moved southwards over Britain.

27. RGB Image from MSG - 18Z October 9 th

28. PV at 18Z October 8 th

29. Relative Humidity at 18Z October 9 th

30. Later...... This weather system became very active on the east coast of Spain Very heavy rain fell near Valencia Floods and one death resulted

31. Lessons...... Value of MSG Water Vapour and Airmass RGB imagery as a “first alert” Cross-Sections are a powerful tool to analyse such a case