1. THE 11-13 MARCH 2006 MID-SOUTH TORNADO OUTBREAK... WHY IT NEVER OCCURRED Dan Valle National Weather Service Memphis, TN

2. Synoptic Overview

3. Upper Air Loop Several Shortwaves +120kt Jet Broad Upper Trough Lifting Out Phasing of Polar/Subtro pical Jets Divergence over Mid- South

4. Surface Features 18Z – Sat 11th NAM

5. Surface Features 00Z – Sun 12th NAM

6. Surface Features 06Z – Sun 12th NAM

7. Surface Features 12Z – Sun 12th NAM

8. Surface Features 18Z – Sun 12th NAM

9. Surface Features 00Z – Mon 13th NAM

10. Surface Features 06Z – Mon 13th NAM

11. 850mb Winds 00-12Z 12th NAM

12. 850mb Winds 00-12Z 13th NAM

13. NAM Sounding 21Z/11th MLCAPE = 3100 J/KG Lifted Index = -5.5 o C 0-3km SRH = 82 m 2 /s 2 0-6km Bulk Shear = 46kts LCL Height = 3157ft

14. NAM Sounding 00Z/12th MLCAPE = 2100 J/KG Lifted Index = -4.8 o C 0-3km SRH = 221m 2 /s 2 0-6km Bulk Shear = 53kts LCL Height = 1927ft

15. NAM Sounding 03Z/12th MLCAPE = 1500 J/KG Lifted Index = -4.0 o C 0-3km SRH = 362m 2 /s 2 0-6km Bulk Shear = 50kts LCL Height = 1271ft

16. NAM 0-1km EHI 00Z/12th ~ 1.5 m 2 /s 2

17. NAM 0-1km EHI 03Z/12th ~ 1.5 m 2 /s 2

18. NAM Sounding 00Z/13th MLCAPE = 2700 J/KG Lifted Index = -7.0 o C 0-3km SRH = 341m 2 /s 2 0-6km Bulk Shear = 58kts LCL Height = 1845ft

19. NAM Sounding 03Z/13th MLCAPE = 2700 J/KG Lifted Index = -7.0 o C 0-3km SRH = 414m 2 /s 2 0-6km Bulk Shear = 57kts LCL Height = 1291ft

20. NAM 0-1km EHI 00Z/13th ~ 4.0 m 2 /s 2

21. NAM 0-1km EHI 03Z/13th ~ 4.5 m 2 /s 2

22. SPC’s Forecast

26. How Bad Was It?

27. Storm Reports for March 11th

28. Storm Reports for March 12th

29. Storm Reports for March 13th

30. What went wrong?

31. 00Z 12th NAMObserved (LZK)

32. Surface Features 00Z/12 th and 06Z/12 th GFS

33. Radar Echos 00Z/12 th and 06Z/12 th GFS

34. Thanks Jason Beaman – NWS Memphis Jonathan Howell – NWS Memphis Gerry Rigdon – NWS Memphis