1. Convectively Coupled Kelvin Waves Multi-Scale Study Over Africa in 2011 Matthew Janiga

2. Overview of Convective Events May-Present Several westward propagating episodes of enhanced convection were observed over Africa in 2011. The average propagation speeds of these events was approximately 20 ms -1, typical of convectively coupled Kelvin waves. The most intense of these events passed over Africa around June 8. 0-10°N TRMM 3B42RT (mm day -1, shaded) and 850 hPa zonal wind anomalies (2, 4, 6 ms -1, contours)

3. Overview of Convective Events May-Present 0-10°N TRMM 3B42RT (mm day -1, shaded) and 850 hPa zonal wind anomalies (2, 4, 6 ms -1, contours) Westward propagating convective events are embedded within the envelope of enhanced rainfall associated with the Kelvin wave. Specifically we see two periods of especially heavy rainfall. 1.) June 8 over West Africa 2.) June 10 over East Africa

4. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

5. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

6. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

7. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

8. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

9. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

10. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

11. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

12. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

13. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

14. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

15. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

16. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

17. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

18. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

19. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

20. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

21. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

22. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

23. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

24. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

25. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

26. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

27. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

28. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

29. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

30. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

31. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

32. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

33. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

34. Kelvin Wave and Mid-Latitude Trough IR (°C, shaded), 500 hPa stream function anomalies (x10 6 m 2 s -1, green contours), and 850 hPa vector wind anomalies

35. Case Summary A clear connection was found to an upper-level mid- latitude trough as indicated by stream function anomalies and cloud pattern. Both heavy rainfall periods began in the afternoon and persisted until early morning consistent with the typical diurnal cycle over West Africa.