Computations of the environmental wind profile throughout the life cycles of Tropical Storm Chantal, Hurricanes Erin, Felix, and Iris, and Michelle are analyzed. Time series of vertical shear quantities from average wind velocity in a hurricane centered 444 km radius circle reveal changes that are associated with hurricane intensity trend changes. They are discussed with respect to the ocean's forcing on intensity change and other potential influences.

Initial numerical model analyses are used from the CIMSS modified NOGAPS, the AVN, and the UKMet Global Model. The relationships between environmental vertical shear and quantitative measurements of cloud asymmetry using GOES IR images are shown. Applications of high density satellite winds to vertical shear measurements are also being investigated.

Preliminary results indicate that easterly shear inhibited TS Chantal's early development, while a shift to weak SSW shear was associated with intensity increase to near hurricane intensity. During the remainder of Chantal's track toward Yucatan, moderate southwesterly shear persisted, but relaxed to weaker shear values that permitted a slow intensification trend that was occurring at landfall.