Global Impacts of the extratropical transition of Hurricane Noel (2007)

The impacts of the extratropical transition (ET) of Hurricane Noel (Oct 31 – Nov 3, 2007) were not confined to coastal sections of North America. In fact, a preliminary analysis of the hemispheric flow indicates that the flow pattern evolved from a wave 1 configuration which resembled a positive phase of the Arctic Oscillation, in the week preceding Noel, to a highly amplified wave 3 configuration in the week following Noel. This amplification seems to be in part attributable to the diabatically enhanced ridging associated with Noel. This ridging in turn led to a strengthening of a trough over Europe, which resulted in the development of an intense cyclone. The role of Noel in the development of this cyclone will be analyzed in detail using a combination of global and high resolution model data. The high resolution data will be examined in order to elucidate the details of the diabatic feedback on the eventual strength of the cyclone. Furthermore, potential vorticity inversion will be utilized in order to asses whether or not the European cyclone would have developed without regard to the ET of Noel.