Predicting Cyclone Damage Potential from Days out to Decades

Three recent U.S. landfalling tropical cyclones (Irene, Isaac and Sandy) have shown that damage from low intensity cyclones can be significant, even far inland from coastal regions. It is therefore important to delineate other potential factors in addition to maximum winds at landfall in driving hurricane damage. Recent work has highlighted the importance of cyclone size in controlling not only the scale of the impacted area, but also the wind duration and likelihood of wind directional change. Further work has shown correlation between local scale wind damage and three cyclone wind parameters: duration, directional change and maximum value.

We expand the concept of the Saffir-Simpson hurricane categorical scale to include these key damaging cyclone parameters in a new Cyclone Damage Potential (CDP) index. Applications of the CDP include real-time forecasting of damage potential and assessing climate variability and change impacts on damage potential. The CDP is further developed using relationships between large-scale climate variables such as potential intensity and steering flow and damage. The resulting index bypasses the need for tropical cyclone-specific data and expands the scope of the index significantly to damage projections on seasonal, decadal and climate timescales.