Balanced boundary layers used in hurricane models

We examine the formulation and accuracy of various approximations made in representing the boundary layer in simple axisymmetric hurricane models, especially those that assume strict gradient wind balance in the radial direction. Approximate solutions for a steady axisymmetric slab boundary‐layer model are compared with a full model solution. It is shown that the approximate solutions are generally poor in the inner core region of the vortex, where the radial advection term in the radial momentum equation is important and cannot be neglected. These results affirm some prior work and have implications for a range of theoretical studies of hurricane dynamics, including theories of potential intensity, that employ balanced boundary‐layer formulations. Copyright © 2008 Royal Meteorological Society