Recorded presentation13B.2
The distribution of helicity and intense convection in simulated tropical cyclones
Kathryn Shontz, UCLA, Los Angeles, CA; and K. L. Corbosiero
Convection within tropical cyclones embedded in strong vertical wind shear environments (> 10 m s-1) has proven to be highly asymmetric, aligned parallel to, and left of, the ambient vertical wind shear vector. This convection is hypothesized to help the storm maintain its intensity despite the harsh conditions, as storm intensities are not negatively impacted one to two days after the onset of shear. Recent observational studies have revealed that vast helicity values, coupled with moderate convective available potential energy and strong shear, imply the existence of supercell-type thunderstorms in some tropical cyclones similar to those in the middle latitudes. Numerical reanalysis of recent tropical cyclones that fit this paradigm will help to resolve outstanding questions about the tropical cyclone's intense convective response to vertical wind shear. Employing the Advanced Hurricane WRF model, Hurricane Gordon (2006) is the focus of a current study and this presentation. Additional simulations of pertinent tropical cyclones will be analyzed in expectation of augmenting the dynamical knowledge of tropical cyclones in a sheared environment.
Session 13B, Tropical Weather Part II
Thursday, 4 June 2009, 9:00 AM-10:00 AM, Grand Ballroom West
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