Numerical Simulation of Rapid Intensifying Hurricane Patricia (2015)

Hurricane Patricia (2015) was an unusual case with extraordinary intensification that broke records in both the peak intensity and the intensification rate over Eastern Pacific. All the operational centers failed to predict Patricia’s extreme intensification, leaving a challenge to the model prediction of the case. In this study, a successful simulation of Patricia is obtained using the NCEP reanalysis as the model initial conditions and lateral boundary conditions, and a nested-grid version of the Weather Research Forecast (WRF) model with the finest resolution of 333 m. The WRF model reproduces Patricia reasonably well in many aspects compared to the best-track, satellite, and the hurricane-penetrating aircraft observations obtained during the Tropical Cyclone Intensity (TCI) field program. For example, the simulated maximum sustained surface wind and the minimum central sea level pressure are 94.5 and 877.6 hPa, respectively, which are comparable to the observed 95 m s^-1 and 872 hPa. The unprecedented rapid intensification (RI) of 54 m s^-1 (24h)^-1 is also captured by the simulation. The model also reproduces the inner- and outer-core structures, such as an intense warm eye, a small sized eyewall, and active rainbands, as observed. In particular, the model predicts a small-sized eyewall less than 10 km measured by the radius of the maximum sustained surface wind. Several sensitivity simulations are performed to study the relative importance of detailed sea-surface temperature, horizontal and vertical resolutions, moisture, and initial vortex structure in determining the rapid intensification of the storm. The related results will be presented during the conference.