August-September
NSF NOAA NRL NCAR UW UM
AGU, San Francisco, 12 December 2006
Katrina Ophelia Rita
Hurricanes investigated in RAINEX
Motivation for RAINEX
Understanding Rapid Intensity Changes
How do interactions of environment, eyewalls & rainbands in the mature storm… …lead to intensity changes like these?
rain
ban
d
Intensity change problem:Intensity change problem:
Intensity of Katrina (2005)
Max Wind Speed (knots)
24 25 2826 2927August
Willoughby 88
High-Resolution Multi-nested Vortex-Following Numerical Models at University of Miami:
• UM/RSMAS Coupled Atmos-Wave-Ocean Model
15 km
1.6 km
5 km
Mini ensemble MM5 and WRF forecasts using GFS, NOGAPS, CMC, and GFDL forecast fields as initial and lateral boundary conditions
Courtesy S. Chen
RitaKatrina
Model forecast of eyewall & rainbandsat 1.6 km resolution
Rain rate
Courtesy S. Chen
Distance from vortex center
Day Day
Rain Wind
KatrinaKatrina
Courtesy S. Chen
RitaRita
Rain WindRain
Distance from vortex center
Day
Courtesy S. Chen
Targeted
RAINEX Flight CoordinationRAINEX Flight Coordination
ELDORA radar
KatrinaKatrina
Katrina-28 AugustKatrina-28 August
ELDORA data
Barnes et al. ‘83
NRL
Katrina-28 AugustKatrina-28 August
Confirms “Barnes” structure
RitaRita
RAINEX Flights in Hurricane RitaRAINEX Flights in Hurricane Rita
Cat. 5
ConcentricEyewalls
Sheared
Concentric eyewalls in RitaConcentric eyewalls in Rita
Unpreceden
ted
Sample cross section through eyewalls of RitaSample cross section through eyewalls of Rita
Horizontal Distance (km)
Hei
ght
(km
)
Eye
Dropsonde in the “moat” region
1802 UTC 22 September ‘05
Rita-22 SeptemberRita-22 September
ELDORA observations
of vorticity in the eyewalls
ELDORA observations
of vorticity in the eyewalls
Maybe first observation of “axisymmetrization”
VorticityVorticity
ELDORA observations of the inner eyewall
ELDORA observations of the inner eyewall
Eye
VorticityVorticity
This has been called“turbo-
boosting” of the eyewall
EyeHeitht (km)
warm air
Vortex on
eyewall
Inner eyewall Outer eyewall
Turbo-boostingTurbo-boosting
Eye
Moat formationMoat formation
2ndary eyewall
taking over
2ndary eyewall
taking overCourtesy Michael Bell
Composite of all ELDORA dataComposite of all ELDORA data
Data AvailabilityData Availability
Katrina Ophelia Rita
Three important storms observed
Innovative satellite-based flight control
First use of ELDORA in hurricanes
Data available via NCAR field catalog
Operations and data analysis aided by high-resolution modeling
RAINEX Technical AccomplishmentsRAINEX Technical Accomplishments
Formation of “moat” documented during eyewall replacement in Rita
ELDORA shows high wave no. vorticity pattern in 2ndary eyewall
ELDORA confirms internal structure of rainband in Katrina
High-res. model captures eyewall replacement in Rita
RAINEX Science DirectionsRAINEX Science Directions
ThanksThanks