| In October of 2001, Hurricane Karen formed in the Atlantic Ocean near Bermuda, moved northward and eventually made landfall at tropical storm strength on the coast of Nova Scotia. The storm was undergoing a transition from a tropical system to an extratropical cyclone as it made its landfall.; Shortly before the storm made its landfall, a Canadian research flight sampled meteorological data along and across the storm's path, by launching dropsondes. The first part of this paper is an attempt to use this data to study the structure of the storm as it moved into higher latitudes and over colder waters. The presence of a very stable boundary layer is evident, with the warm moist tropical air residing above. In the second part of the paper, the dropsonde data is used to try to improve the simulation of extratropical transition by a high resolution numerical weather prediction model. The conclusions point out some areas where improvements in the model and in its initial conditions might help in future modelling studies. (Abstract shortened by UMI.)... |
