Estimating Tropical Cyclone Precipitation Risk over the Continental North America

In 2017, two landfalling major hurricanes Harvey and Irma featured a busy Atlantic hurricane season. Heavy precipitation from Harvey induced massive inland flooding in Houston metropolitan area and caused 82 death tolls and massive damages in infrastructure and economics loss that worth $190 billion. Many regions on the Atlantic coast of North America are at risk of inland flooding that is caused by extreme rainfalls from Tropical Cyclones. In this study, we use two independent datasets/approaches to access and compare the long-term risk of TCP over the Continental North America. The first approach is using a recently developed Moving Radius of outermost closed isobar Boundary Technique (MRBT) to extract the daily TCP records from rain gauges and interpolate them into grids at 0.25° for all storms made landfall from 1930 to 2017. The second approach is to apply the synthetic hurricane technology to generate thousands of synthetic Tropical Cyclones and their rain fields, which significantly enlarged the sample size and tails of distributions for the existing records of historical TCs. We will look at spatial and temporal variations for both approaches and evaluate how they agrees and differs. TCP risk curves will be analyzed for selected metropolitan areas with large population and economics at stake of extreme TCP for our study region.