Fig. 2. 200 mb streamline and isotach analysis from a 1975 to 1991 climatology for the month of August. Windspeeds are contoured every 4 ms-1 with shading added for those winds greater than 8 ms-1. The dark dashed line indicates the mean TUTT axis. Closed circles denote regions where AVN 48 h wind errors were calculated. Climatological data are provided by the archive of tropical North Atlantic 200 mb winds courtesy of the National Oceanographic and Atmospheric Administration's Hurricane Research Division. Details on the dataset are available in Shapiro (1987).