Hurricanes possess an intrinsic ability to remain vertically aligned when tilted by external vertical shear flow. This resiliency of the vortex has been explained using dry dynamical models. Neglected in these models of the vortex-shear interaction is the azimuthal convective asymmetry that develops within and outside the hurricane eyewall. Observations and "full physics" numerical simulations show that in the case of strongly sheared hurricanes, the development of persistent azimuthal convective asymmetry often precedes the top-down weakening of the storm. Here we examine two days of observations of Hurricane Guillermo (1997) as it encountered moderate vertical shear during its strengthening phase, and then reached its maximum intensity. In particular we focus on the upper-level evolution of the vortex flow using 10 consecutive 3D dual-Doppler wind composites over 6 hours on each day. Insights are provided into the impact of the observed convective asymmetry on the upper-level flow evolution through a dynamical analysis of the data, as well as preliminary results from idealized numerical simulations using a fully compressible, nonhydrostatic primitive equation model.