vorticity structures accompanying eyewall replacement in hurricane rita (2005)
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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. - PowerPoint PPT PresentationTRANSCRIPT
Vorticity Structures AccompanyingVorticity Structures AccompanyingEyewall Replacement in Hurricane Rita (2005)Eyewall Replacement in Hurricane Rita (2005)
R.A. Houze, Jr., and B.F. SmullR.A. Houze, Jr., and B.F. SmullDepartment of Atmospheric SciencesDepartment of Atmospheric Sciences
University of WashingtonUniversity of Washington
AMS 28th Conf. on Hurricanes & Tropical MeteorologyAMS 28th Conf. on Hurricanes & Tropical MeteorologyOrlando, Florida - 29 April 2007Orlando, Florida - 29 April 2007
Photo within Rita (CAT 4-->5) on 21 Sept 2005 courtesy M. Black, Photo within Rita (CAT 4-->5) on 21 Sept 2005 courtesy M. Black, NOAA/AOML/HRDNOAA/AOML/HRD
Multi-day Intensity Trends for Hurricane Rita
Period of ELDORA Observations DocumentingConcentric Eyewall Structure on 22 September 2005
Best-track Central Pressure & Max Sustained Surface Winds
22 September 2005 - GOES Visible + P-3 TracksEyewall Replacement Phase
M a toen do ac r ySarymirP
Concentric Eyewall Reflectivity Structure2.0 km MSL
1801-1820 UTC NRL P-3/ELDORA Circumnavigation (Units: dBZ)
Double Wind Maximum - Horizontal Wind Speed2.5 km MSL
1801-1820 UTC NRL P-3/ELDORA Circumnavigation (Units: m/s)
M a toen do ac r ySarymirP
Double Wind Maximum - Horizontal Wind Speed0.5 km MSL
1801-1820 UTC NRL P-3/ELDORA Circumnavigation(Units: m/s)
M a toen do ac r ySarymirP
Patterns of Vertical VorticityAccompanying Eyewall Replacement
Patterns of Vertical VorticityAccompanying Eyewall Replacement
~Axisymmetrized Primary Eyewall vs. High Wavenumber Secondary Eyewall Structures
NW Quadrant80 x 80 km2
SE Quadrant80 x 80 km2
Location of NW & SE Quadrant Analysis Domains( Units: 10-4 s-1)
W E
NW Quadrant
NW Quadrant Vorticity - 1.25 km MSL Contrasting scale/orientation of primary vs. secondary eyewall
Vorticity features
Evidence of vorticity dipoles in Evidence of vorticity dipoles in region of secondary eyewall region of secondary eyewall
formation formation
Evidence of vorticity dipoles in Evidence of vorticity dipoles in region of secondary eyewall region of secondary eyewall
formation formation
( Units: 10-4 s-1)Marks and Houze 1983
WE
Eye Moat
NW QuadrantRadial Section
Radial Section - Reflectivity: Vertically coherent concentric eyewall/moat structure -
Contrasting depth/tilt of primary & secondary eyewall features
(Units: dBZ)
WE
Radial Section - Horizontal Wind Speed Contrasting depth/slope of isotach patterns -
Comparatively shallow, sloped secondary eyewall wind maxima
Eye Moat
NW QuadrantRadial Section
(Units: m/s)
WE
Radial Section - Vertical Vorticity Corresponding contrasts in primary vs. secondary eyewall Tremendous vertical coherence of secondary eyewall dipoles
Eye Moat
NW QuadrantRadial Section
( Units: 10-4 s-1)
WE
Radial Section - Vertical Vorticity& Doppler-Derived Air Motion Vectors
Tendency for & w to be correlated
Eye Moat
NW QuadrantRadial Section
( Units: 10-4 s-1)
Reproducibility of Observed StructuresIn Other Quadrants
Reproducibility of Observed StructuresIn Other Quadrants
Vertical Vorticity - 2.0 km MSLRadial section crosses intense primary eyewall mesovortex &
high wavenumber secondary eyewall features beyond
WSW
ENE
(Units: 10-4 s-1)
Radial Section - Vertical Vorticity
ENEWSW
Eye
SE Quadrant Radial Section
( Units: 10-4 s-1)
Tangential Section Vorticity @ 2.0 km - Evidence of high wavenumber structures
SW
NE
( Units: 10-4 s-1)
Corresponding Tilted VorticityStructures Structures within Secondary Eyewall
NESW
x x x x x
(Units: 10-4 s-1)SE Quadrant Tangential Section
FlowShear
Wind Speed in Secondary Eyewall Near-sfc wind maxima at ~5 km spacing
Structures within elevated (2-5 km) layer tilt downshear
x x x x x
(Units: m/s)SE Quadrant Tangential Section
Shear
NESW
Conclusions
•Unprecedented high-resolution view of concentric eyewall structure & dynamics
•Primary eyewall “triangular” with upright local vorticity maxima
•Secondary eyewall
High wavenumber (~25) wind perturbationsWind max strong but shallow & slopedHigh wavenumber vorticity extrema
Tilt radially outward and tangentially downshearTend to correlate with wPossibly associated with near-surface wind maxima
Thanks for your attention…Thanks for your attention…
21 Sept 2005 - GOES Visible + P-3 Tracks
21 Sept 2005 - LF/WSR-88D CompositeIntense Cat-5 Phase
22 September 2005 - GOES Visible + P-3 TracksEyewall Replacement Phase
23 Sept 2005 - WSR-88D Composite + TracksStrongly-sheared Landfall Phase
Mesovortex along Primary Eyewall of Rita Associated Reflectivity @ 0.5 km MSL
(Units: dBZ)
Mesovortex along Primary Eyewall of Rita Wind Speed @ 0.5 km MSL
(Units: m/s)
Mesovortex Along Primary Eyewall of Rita Vertical Vorticity @ 0.5 km MSL
(Units: 10-4 s-1)
3-D Exploration of Mesovortex Structure Map @ 0.5 km MSL & Radial Cross Section)
dBZdBZVorticity (Vorticity ())
( Units: 10-4 s-1)
Possible Convective Origins Suggested byAccompanying Precipitation Structures
x x x x x
(Units: dBZ)SE Quadrant Tangential Section
Radial Section - Reflectivity
ENEWSW
Eye Moat
SE Quadrant Radial Section
(Units: dBZ)