Evaluation of tropical near-surface wind forecasts using ground observations

Abstract

This paper evaluates near-surface wind forecasts of the Weather Research and Forecasting (WRF) model with the aim for developing an accurate wind forecasting system for northeastern Thailand. Hourly wind speeds and directions at 65 and 90 m above ground covering 3 full months in 2012 forecasted using 3 different methods are evaluated using observations from 12 and 9 wind measuring stations, respectively. Analyses and forecasts from the NCEP Global Forecast System are used for initial and boundary conditions. Forecasted wind fields from 6 to 12 h after the initial time are used for accuracy evaluation. Results show that grid nudging significantly improves forecast accuracies. Employing USGS topography at 0.0083° resolution instead of SRTM topography at 90-m resolution does not affect accuracies of wind forecasts at 5-km resolution much. Forecasted wind speeds and directions agree well with observations at both altitudes with good utility for wind speeds above 2 m/s. The wind forecasting system illustrated in this paper is useful for wind energy planning and management in northeastern Thailand.