Torrential rainfall processes associated with a landfall of Typhoon Fitow (2013): A three-dimensional WRF modeling study

摘要

In this study, Weather Research and Forecasting Model (WRF) with triply nested grid and the finest grid size of 3 km is utilized to simulate Typhoon Fitow (2013). The simulation is verified with available observations. The model well captures the track, eyewall, and rainband structures and also reproduces radar reflectivity and vertical profiles of temperature, water vapor mixing ratio, and winds. Area mean budget shows that water vapor convergence leads to condensation, which produces rainfall through accretion of cloud water by rain and melting of graupel. Over convective regions, water vapor convergence generates condensation, which feeds convective rainfall and supports transport of raindrops to stratiform regions through accretion of cloud water by rain. Over stratiform regions, melting of graupel and the transport of raindrops from convective regions are major sources for stratiform rainfall. The results are further strengthened by the analysis of the data in a storm-following coordinate using different convective-stratiform rainfall separation schemes.