There has been significant success in recent years in determining the maximum potential intensity, or MPI, that tropical cyclones can attain. Both theory and observation agree that sea surface temperature is a crucial ingredient in determining the MPI. Much less understood however, are the mechanisms responsible for the rapid intensity fluctuations often observed in tropical cyclones. Presently, intensification mechanisms are broadly classified into three categories: the air-sea interaction, internal storm interactions, and external storm interactions. The air-sea interaction, as the main energy source for the tropical cyclone, excites core convection through sea surface latent heat fluxes. Internal storm interactions are composed of both eye-eyewall processes and anomalous potential vorticity interactions. External influences result from the weakened inertial stability in the outflow layer associated with the decay of the primary circulation with height.

This study will focus on the influence of outflow layer asymmetries on intensity fluctuations. In particular, if pre-existing outflow channels in the tropical cyclone environment facilitate more rapid growth than would otherwise occur. Previous studies have focused on the role of angular momentum fluxes or potential vorticity superposition principles to explain strengthening. These techniques have yet to yield consistent results for the multitude of possible environmental interactions. Here, the idea is not so much to put a quantitative seal on environmental influences as to explore, through idealized three dimensional numerical simulations, the impact of changing environmental conditions on tropical cyclone intensity and core convection. the premise of this work is rooted in MPI theory. These theories do not incorporate the work done against the surrondings or the impact of the surroundings upon the tropical cyclone. Outflow channels can provide low inertial stability so that minimal work is required to vent the outflow against the radial pressure gradient and may provide regions of convergence to force subsidence against positive static stability. If there are pre-existing outflow channels in the vicinity of the tropical cyclone it is reasonable to expect less energy expenditures on behalf of the cyclone to exhaust it's anticyclonic angular momentum.

The numerical work will be completed using a three-dimensional primitive equation model. To simulate the effect of pre-existing outflow channels on intensification the tropical cyclone-jet streak interaction will be studied. This setup permits a region of weak inertial stability on the anticyclonic shear side of the jet for which the tropical cyclone outflow can plug into. By using various jet strengths and orientations with respect to the storm it is hoped a clearer picture of the environmental impact upon the tropical cyclone, the convective core region in particular, will be obtained.