Simulation of Track and Landfall of Tropical Cyclone Viyaru and Its Associated Strom Surges Using NWP Models

摘要

Simulation of track and landfall of the tropical cyclone Viyaru that formed over the southern Bay of Bengal during 11-16 May 2013 has been carried out using Weather Research and Forecasting (WRF) and MRI model. The WRF model was run in a single domain of 9 km horizontal resolution using KF cumulus parameterization schemes, WSM6 micro physics and YSU planetary boundary layer scheme. The model was run for 24, 48, 72 and 96 hrs using NCEP FNL initial and lateral boundary condition. The model has successfully predicted the tracks, re-curvature, areas and time of landfall of the selected tropical cyclone Viyaru. Even in the 96 hrs predictions the model has successfully predicted with reasonable accuracy. The lowest position error was found only 56 km and lowest time error was found 01 hour. The results clearly demonstrate that the track prediction error increases as the forecast hours increases except 24 hrs simulation. However, these results show the advantage of using WRF model with high resolution in prediction of the selected tropical cyclone Viyaru over the Bay of Bengal. Model simulated track was compared with that of BMD observed track and found that the model has captured the track in reasonably well. The storm surges and maximum tide was also simulated by MRI model at the time of landfall of Viyaru and compared with the BMD’s and Inland Waterways Transport Authority’s (BIWTA) estimated storm surges and maximum tide data. It is found that the model has also simulated the storm surges and maximum tide due to Viyaru in 24-hrs advance of landfall time.