Modelling the Typhoon Haiyan storm surge on eastern Philippines using weather research and forecasting-advanced circulation

The Philippines is particularly vulnerable to the hazards presented by tropical cyclones, which make landfall an average of nine times in the country. Typhoon Haiyan (November 2013) proved to be an especially devastating storm, producing storm surges that made inland flooding along the coastline of eastern Philippines, causing an estimated $14 billion in damages with 6340 reported fatalities. A characterization of the effects of Typhoon Haiyan was the main objective of this study and was carried out by numerical modelling of the storm. 10-m surface wind and surface pressure data from the Weather Research and Forecasting (WRF) simulations were interpolated and forced into the 2D, depth-averaged, hydrodynamic Advanced Circulation (ADCIRC) model in order to characterize the wind and water elevation at specified locations severely affected by the typhoon. The Joint Typhoon Warning Center Best Track Data was also used to compare the results obtained from the WRF forcing. The results showed a 1.3 m storm surge at Tacloban using WRF forcing and 3.5 m using the JTWC forcing. Validation with the Typhoon Haiyan storm surge database of the (DOST-Project NOAH) showed that the simulated storm surge was underpredicted for both types of forcing relative to the 4.5 storm tide recorded by Project NOAH, due to the insufficient capturing of maximum sustained winds (200 kph) and central pressure (950 hPa) by the WRF simulations. Future studies can revolve around using wave forcing to capture the wave effects of a typhoon during a storm surge