GPS Dropwindsonde Wind Profiles in Hurricanes and Their Operational Implications

Abstract The recent development of the global positioning system (GPS) dropwindsonde has allowed the wind and thermodynamic structure of the hurricane eyewall to be documented with unprecedented accuracy and resolution. In an attempt to assist operational hurricane forecasters in their duties, dropwindsonde data have been used in this study to document, for the first time, the mean vertical profile of wind speed in the hurricane inner core from the surface to the 700-hPa level, the level typically flown by reconnaissance aircraft. The dropwindsonde-derived mean eyewall wind profile is characterized by a broad maximum centered 500 m above the surface. In the frictional boundary layer below this broad maximum, the wind decreases nearly linearly with the logarithm of the altitude. Above the maximum, the winds decrease because of the hurricane's warm core. These two effects combine to give a surface wind that is, on average, about 90% of the 700-hPa value. The dropwindsonde observations largely confirm recent...

[1]  John F. Gamache,et al.  Dual-Aircraft Investigation of the Inner Core of Hurricane Norbert. Part I: Kinematic Structure , 1992 .

[2]  James L. Franklin,et al.  The NCAR GPS Dropwindsonde , 1999 .

[3]  James L. Franklin,et al.  An Investigation of Omega Windfinding Accuracy , 1985 .

[4]  F. Gifford A SIMULTANEOUS LAGRANGIAN-EULERIAN TURBULENCE EXPERIMENT1 , 1955 .

[5]  Hugh E. Willoughby,et al.  Concentric Eye Walls, Secondary Wind Maxima, and The Evolution of the Hurricane vortex , 1982 .

[6]  Frank D. Marks,et al.  Inner Core Structure of Hurricane Alicia from Airborne Doppler Radar Observations , 1987 .

[7]  David F. Jorgensen Mesoscale and Convective-Scale Characteristics of Mature Hurricanes. Part I: General Observations by Research Aircraft , 1984 .

[8]  F. H. Hawkins,et al.  Hurricane Hilda, 1964 II. Structure and Budgets of the Hurricane on October 1, 1964 , 1968 .

[9]  David P. Jorgensen,et al.  Mesoscale and Convective-Scale Characteristics of Mature Hurricanes. Part II. Inner Core Structure of Hurricane Allen (1980) , 1984 .

[10]  Peter G. Black,et al.  The relationship of hurricane reconnaissance flight-level wind measurements to winds measured by NOAA's oceanic platforms , 1990 .

[11]  Tastuo Izawa On the mean wind structure of typhoon , 1964 .

[12]  J. Angell,et al.  Lagrangian‐Eulerian time‐scale ratios estimated from constant volume balloon flights past a tall tower , 1971 .

[13]  Mark D. Powell,et al.  Evaluations of Diagnostic Marine Boundary-Layer Models Applied to Hurricanes , 1980 .

[14]  W. Frank,et al.  The Structure and Energetics of the Tropical Cyclone I. Storm Structure , 1977 .

[15]  R. H. Simpson,et al.  The hurricane disaster potential scale , 1974 .

[16]  F. Gifford,et al.  A SIMULTANEOUS LAGRANGIAN-EULERIAN TURBULENCE EXPERIMENT , 1955 .

[17]  R. C. Sheets The National Hurricane Center—Past, Present, and Future , 1990 .