1. Vorticity Structures Accompanying Eyewall Replacement in Hurricane Rita (2005) R.A. Houze, Jr., and B.F. Smull Department of Atmospheric Sciences University of Washington AMS 28th Conf. on Hurricanes & Tropical Meteorology Orlando, Florida - 29 April 2007 Photo within Rita (CAT 4-->5) on 21 Sept 2005 courtesy M. Black, NOAA/AOML/HRD Photo within Rita (CAT 4-->5) on 21 Sept 2005 courtesy M. Black, NOAA/AOML/HRD

2. Multi-day Intensity Trends for Hurricane Rita Period of ELDORA Observations Documenting Concentric Eyewall Structure on 22 September 2005 Best-track Central Pressure & Max Sustained Surface Winds

3. 22 September 2005 - GOES Visible + P-3 Tracks Eyewall Replacement Phase

4. M a t o e n d o a c r y S a r y m i r P Concentric Eyewall Reflectivity Structure 2.0 km MSL 1801-1820 UTC NRL P-3/ELDORA Circumnavigation (Units: dBZ)

5. Double Wind Maximum - Horizontal Wind Speed 2.5 km MSL 1801-1820 UTC NRL P-3/ELDORA Circumnavigation (Units: m/s) M a t o e n d o a c r y S a r y m i r P

6. Double Wind Maximum - Horizontal Wind Speed 0.5 km MSL 1801-1820 UTC NRL P-3/ELDORA Circumnavigation (Units: m/s) M a t o e n d o a c r y S a r y m i r P

7. Patterns of Vertical Vorticity Accompanying Eyewall Replacement Patterns of Vertical Vorticity Accompanying Eyewall Replacement

8. ~Axisymmetrized Primary Eyewall  vs. High Wavenumber Secondary Eyewall Structures NW Quadrant 80 x 80 km 2 SE Quadrant 80 x 80 km 2 Location of NW & SE Quadrant Analysis Domains (  Units: 10 -4 s -1 )

9. WE NW Quadrant NW Quadrant Vorticity - 1.25 km MSL Contrasting scale/orientation of primary vs. secondary eyewall Vorticity features Evidence of vorticity dipoles in region of secondary eyewall formation (  Units: 10 -4 s -1 ) Marks and Houze 1983

10. WE EyeMoat NW Quadrant Radial Section Radial Section - Reflectivity: Vertically coherent concentric eyewall/moat structure - Contrasting depth/tilt of primary & secondary eyewall features (Units: dBZ)

11. WE Radial Section - Horizontal Wind Speed Contrasting depth/slope of isotach patterns - Comparatively shallow, sloped secondary eyewall wind maxima EyeMoat NW Quadrant Radial Section (Units: m/s)

12. WE Radial Section - Vertical Vorticity Corresponding contrasts in primary vs. secondary eyewall  Tremendous vertical coherence of secondary eyewall dipoles EyeMoat NW Quadrant Radial Section (  Units: 10 -4 s -1 )

13. WE Radial Section - Vertical Vorticity & Doppler-Derived Air Motion Vectors Tendency for  & w to be correlated EyeMoat NW Quadrant Radial Section (  Units: 10 -4 s -1 )

14. Reproducibility of Observed Structures In Other Quadrants Reproducibility of Observed Structures In Other Quadrants

15. Vertical Vorticity - 2.0 km MSL Radial section crosses intense primary eyewall mesovortex & high wavenumber secondary eyewall features beyond WSW ENE (Units: 10 -4 s -1 )

16. Radial Section - Vertical Vorticity ENEWSW Eye SE Quadrant Radial Section (  Units: 10 -4 s -1 )

17. Tangential Section Vorticity @ 2.0 km - Evidence of high wavenumber structures SW NE (  Units: 10 -4 s -1 )

18. Corresponding Tilted Vorticity Structures Structures within Secondary Eyewall NESW x x x x x (Units: 10 -4 s -1 ) SE Quadrant Tangential Section Flow Shear

19. Wind Speed in Secondary Eyewall Near-sfc wind maxima at ~5 km spacing Structures within elevated (2-5 km) layer tilt downshear xxxx x (Units: m/s) SE Quadrant Tangential Section Shear NESW

20. Conclusions Unprecedented high-resolution view of concentric eyewall structure & dynamics Primary eyewall “triangular” with upright local vorticity maxima Secondary eyewall  High wavenumber (~25) wind perturbations  Wind max strong but shallow & sloped  High wavenumber vorticity extrema  Tilt radially outward and tangentially downshear  Tend to correlate with w  Possibly associated with near-surface wind maxima

21. Thanks for your attention…

22. 21 Sept 2005 - GOES Visible + P-3 Tracks

23. 21 Sept 2005 - LF/WSR-88D Composite Intense Cat-5 Phase

24. 22 September 2005 - GOES Visible + P-3 Tracks Eyewall Replacement Phase

25. 23 Sept 2005 - WSR-88D Composite + Tracks Strongly-sheared Landfall Phase

26. Mesovortex along Primary Eyewall of Rita Associated Reflectivity @ 0.5 km MSL (Units: dBZ)

27. Mesovortex along Primary Eyewall of Rita Wind Speed @ 0.5 km MSL (Units: m/s)

28. Mesovortex Along Primary Eyewall of Rita Vertical Vorticity @ 0.5 km MSL (Units: 10 -4 s -1 )

29. 3-D Exploration of Mesovortex Structure Map @ 0.5 km MSL & Radial Cross Section) dBZ Vorticity (  ) (  Units: 10 -4 s -1 )

30. Possible Convective Origins Suggested by Accompanying Precipitation Structures x x x x x (Units: dBZ) SE Quadrant Tangential Section

31. Radial Section - Reflectivity ENEWSW EyeMoat SE Quadrant Radial Section (Units: dBZ)