Examination of Land-falling Tropical Cyclones in an IPCC Extreme Climate Scenario

Land-falling tropical cyclone (TC) properties are examined in an extreme scenario of future climate for the years 2098-2100 using a high resolution, multiply-nested numerical weather prediction (NWP) model. The study is facilitated by taking pseudo-radiosonde observations from the NCAR Community Climate Model System 4 [CCSM4] and IPSL [CM5A] climate model simulations for the Representative Concentration Pathway (RCP) 8.5 scenario of the Fifth Climate Model Intercomparison Project (CMIP5). The pseudo-radiosondes are assimilated by the Navy 4DVAR Data Assimilation System (NAVDAS-AR) to create global analyses consistent with the future extreme climate for the Navy Global Environmental Model (NAVGEM). These future global analyses are then used to drive a multiply-nested regional TC prediction model (the Coupled Ocean-Atmosphere Mesoscale Prediction System – Tropical Cyclones [COAMPS-TC]) at a cloud resolving horizontal resolution (5-km). The COAMPS-TC simulations are seeded using a Monte Carlo approach and the results are examined with particular focus on the impact of land-falling TCs. Overall, the distribution of simulations exhibits a tail of distinctly higher intensity TCs than are observed in the present climate, reinforcing the idea that future extreme climates may support exceptionally strong TCs. Distributions and composites of TC properties including intensity, tracks, scale, structure, and precipitation will be shown. The results will offer a window into how land-falling TCs in a future climate may differ from those in the present climate.