Thursday, 1 May 2008: 9:30 AM
Palms H (Wyndham Orlando Resort)
A new technique for relating central pressure and maximum winds in tropical cyclones is presented, together with a method of objectively determining the Holland b parameter that includes the pressure drop into the cyclone center, intensification rate, latitude and translation speed. By allowing the b-parameter to vary, a realistic scatter in maximum winds for a given central pressure is obtained. This provides an improvement over traditional approaches that provide a unique wind for each central pressure. It can also be used to derive a radial wind profile to fit a core profile to outer wind observations from scatterometers.
I recommend that application of the Dvorak satellite interpretation technique be limited to derivation of a central pressure, with this wind model then providing the maximum wind estimates. I also find that the recent North Atlantic data archive is largely derived from use of the Dvorak technique, even when hurricane reconnaissance data are available, and that Dvorak overestimates maximum winds for intense hurricanes. Application of the P-W model to the full North Atlantic hurricane archive confirms the findings by Landsea (1993) of a substantial overestimation of maximum winds between 1950 and 1980 and shows that the Landsea corrections do not completely remove this bias.
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