The stability of different symmetric wind profiles which have been used to represent tropical storms or tornados are investigated or reexamined. The stability analysis is carried out for nondivergent barotropic vortices centered in polar coordinates. Due to rapid changes in the vorticity gradient near the center, the stability domain boundary is sensitive to the finite-difference resolution of the differential equation. In the outer part of the vortex where the wind profile is usually smooth, the position of the outer boundary has less influence on the stability results. The maximum number of branches of unstable modes supported by the basic wind profile is determined by the number of times the basic vorticity gradient changes sign within the domain.
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