 Reconnaissance Aircraft and surface reports confirmed the existence of a circulation . Dean moved northwestward at 22 mph ( 35 km / h ) , under the influence of the Bermuda High to its northeast . The storm strengthened slightly to reach winds of 60 mph ( 95 km / h ) later on August 22 , though the circulation was exposed on the western edge of the convection due to the storm 's quick forward motion and persistent wind shear . Initial forecasts predicted the shear to decrease , allowing Dean to attain hurricane status with winds of over 80 mph ( 130 km / h ) . However , an upper @-@ level trough produced an increase of shear over the storm , and by August 23 Dean weakened to a tropical depression . Hours later , the circulation dissipated , and Dean degenerated into a tropical wave to the east of the Bahamas . Regeneration was considered unlikely at the time . 
