Wind setup

Wind setup, also known as wind effect or storm effect, refers to the rise in water level in seas, lakes, or other large bodies of water caused by winds pushing the water in a specific direction. As the wind moves across the water’s surface, it applies shear stress to the water, generating a wind-driven current. When this current encounters a shoreline, the water level increases due to the accumulation of water, which creates a hydrostatic counterforce that balances the shear force applied by the wind.^[1][2]

During storms, wind setup forms part of the overall storm surge. For example, in the Netherlands, wind setup during a storm surge can raise water levels by as much as 3 metres above normal tidal levels. In tropical regions, such as the Caribbean, wind setup during cyclones can elevate water levels by up to 5 metres. This phenomenon becomes especially significant when water is funnelled into shallow or narrow areas, leading to higher storm surges.^[3]

Examples of the effects of wind setup include Hurricanes Gamma and Delta in 2020, during which wind setup was a major factor when strong winds and atmospheric pressure drops caused higher-than-expected coastal flooding across the Yucatán Peninsula in Mexico.^[4] Similarly, in California’s Suisun Marsh, wind setup has been show to be a significant factor affecting local water levels, with strong winds pushing water into levees, contributing to frequent breaches and flooding.^[5]