Hurricane Isabel (2003): New Insights into the Physics of Intense Storms. Part I. Mean Vortex Structure and Maximum Intensity Estimates
Abstract
Hurricane Isabel was at or near category 5 on the Saffir Simpson scale (surface wind speed > 67 m s[expn -1]) from 12 to 14 September 2003. On 13 September, the strongest known horizontal wind (107 m s[expn -1]) recorded in a hurricane was obtained by a National Center for Atmospheric Research (NCAR) GPS dropwindsonde at 1752 UTC (Aberson et al. 2006, hereafter Part II; Hock and Franklin 1999). Multiple aircraft missions by the National Oceanic and Atmospheric Administration (NOAA) and U.S. Air Force (USAF) Hurricane Hunters obtained a uniquely comprehensive observational dataset during this period. Multiple dropwindsondes, in situ flight level data, airborne Doppler radar data, and high resolution satellite imagery provide an unprecedented view of the kinematic and thermodynamic structure of Isabel over 3 days. A synthesis of flight-level and dropwindsonde data during 12-14 September along with a detailed description of the dataset and analysis methodology is reported elsewhere (Bell and Montgomery 2006, manuscript submitted to Mon. Wea. Rev.); the focus of this two-part study is the analysis for 13 September. A nearly circular core of deep eyewall convection at 2218 UTC 13 September is represented in Fig. 1a by the cold (red) 85-GHz brightness temperature. Nonaxisymmetric structures inside the eye with cloud bands connecting to the eyewall are also apparent in the low-level stratus clouds at 1745 UTC (Fig. 1b), along with a pentagon-shaped region of high reflectivity seen in a NOAA P-3 lower-fuselage radar image at approximately the same time (Fig. 1c).
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2006
- Accession Number
- ADA594100
Entities
People
- Michael L. Black
- Michael M Bell
- Michael T. Montgomery
- Sim D. Aberson
Organizations
- Naval Postgraduate School