The application of adaptive finite elements for reliable numerical simulations requires they be executed in an automated manner with explicit control of the approximations made. In these applications, meshes are used to discretize the problem domains. Since there are no reliable a priori methods to control the approximation errors, adaptive methods must be applied. Adaptive meshing procedures provide a powerful tool for attacking problems such as fluid flows that can develop highly anisotropic solutions and can only be located and resolved through adaptivity. A mesh modification based procedure has been developed that accepts an anisotropic mesh size field defined using entity level correction indicators evaluated on the previous solution step. The mesh size field drives mesh refinement and coarsening operations on the mesh to yield a mesh that satisfies the requested mesh size field.