Observations and forecasting of a low visibility event in Hong Kong on New Year’s Eve

This paper investigates a unique low visibility event induced by haze in Hong Kong on New Year’s Eve 2023, characterized by significant spatial differences in visibility across Victoria Harbour. The study discusses the meteorological conditions, including weak northeast monsoon and localized wind variations, leading to the rapid fluctuation in visibility. Ground observations, remote-sensing data, and Aerosol Optical Depth (AOD) from satellites were utilized to analyze the phenomenon. The research highlights the impact of surface winds, boundary layer stability, and aerosol dispersion in understanding the visibility variation. Additionally, the study assesses the effectiveness of the current forecasting techniques, especially the high-resolution numerical weather prediction model utilized by Hong Kong’s Environmental Protection Department. The paper serves as a valuable resource for weather forecasters in the region and suggests further studies using high-resolution models to better understand localized visibility deterioration events.