The Influence Of Mid-Latitude Troughs On The Predictability Of Rapidly Intensifying (Ri) Hurricanes In The Gulf Of Mexico
Presenter: Samuel Dahl1
Co-Author(s): -
Advisor(s): Dr. Eyad Atallah
1Department of Hydrology and Atmospheric Sciences, University of Arizona
Rapidly intensifying (RI) hurricanes in the Gulf of Mexico (e.g., Katrina, 2005; Laura, 2021) have caused substantial loss of life and economic damage upon landfall in the Southern States. These storms are often forecasted poorly, with under-forecasting of intensity at landfall just a couple days out in the forecast period (Cangialosi, 2021). This low bias can mean that people along the Gulf Coast are preparing for a far less intense storm than will likely make landfall, costing lives and dollars. The National Hurricane Center (NHC) uses both dynamical and statistical models to forecast hurricane intensity. In the Atlantic basin, dynamical models have been more skillful at predicting rapid intensification than statistical models in recent. A new RI metric produced by the NHC shows that RI forecasts have improved by 20-25% since 2015 (DeMaria et al. 2021). However, one reason for continued low skill in RI forecasting in the Gulf region is the lack of understanding of the effects of mid-latitude troughs on tropical systems. Our objective is to explore the effects of mid-latitude troughs on hurricane RI and assess whether forecast skill is influenced by the presence of mid-latitude systems. Using several research lenses, including PV dynamics and an analysis of official NHC forecast skill, initial findings show that mid-latitude cyclones do not directly impact RI. Rather, internal tropical cyclone dynamics and principles of ocean-atmosphere coupling likely lead to unexpected RI prior to landfall.