Discrepancies on Storm Surge Predictions by Parametric Wind Model and Numerical Weather Prediction Model in a Semi-Enclosed Bay: Case Study of Typhoon Haiyan

Tso-Ren Wu,Simon C Lin,Chun-Wei Lin,Yu-Lin Tsai,Chuan-Yao Lin,Eric Yen

doi:10.3390/w12123326

Abstract

This study explores the discrepancies of storm surge predictions driven by the parametric wind model and the numerical weather prediction model. Serving as a leading-order storm wind predictive tool, the parametric Holland wind model provides the frictional-free, steady-state, and geostrophic-balancing solutions. On the other hand, WRF-ARW (Weather Research and Forecasting-Advanced Research WRF) provides the results solving the 3D time-integrated, compressible, and non-hydrostatic Euler equations, but time-consuming. To shed light on their discrepancies for storm surge predictions, the storm surges of 2013 Typhoon Haiyan in the Leyte Gulf and the San Pedro Bay are selected. The Holland wind model predicts strong southeastern winds in the San Pedro Bay after Haiyan makes landfall at the Leyte Island than WRF-ARW 3 km and WRF-ARW 1 km. The storm surge simulation driven by the Holland wind model finds that the water piles up in the San Pedro Bay and its maximum computed storm surges are almost twice than those driven by WRF-ARW. This study also finds that the storm surge prediction in the San Pedro Bay is sensitive to winds, which can be affected by the landfall location, the storm intensity, and the storm forward speed. The numerical experiment points out that the maximum storm surges can be amplified by more 5–6% inside the San Pedro Bay if Haiyan’s forward speed is increased by 10%.

Highlights

IntroductionStorm surges caused by tropical storms can have a significant impact on coastal facilities [1]
Storm surges caused by tropical storms can have a significant impact on coastal facilities [1].In some cases, storm surges can interact with tides [2,3] and wind waves [4,5,6]
The 10-m winds and the sea-level pressures of Holland wind model (HWM) are compared to the observed data and Discussions at Results the Guiuan weather station, East Samar

Summary

Introduction

Storm surges caused by tropical storms can have a significant impact on coastal facilities [1]. Storm surges can interact with tides [2,3] and wind waves [4,5,6]. When a storm approaches coastal regions, winds can amplify the height of storm surges locally at least two times more than that in the open ocean [5,6]. To perform an accurate storm surge modeling, having a better understanding of storm-wind fields is critical. The uncertainties of storm surge predictions can attribute to the input data (e.g., bathymetry and winds), physics consideration (coupling with waves, tides, river flows, etc.), and numerical settings

Methods

Results

Conclusion