Saline water intrusion in relation to strong winds during winter cold outbreaks: North Branch of the Yangtze Estuary

•Strong wind events and saline water intrusion correlate significantly.•Strong northerly and northeasterly winds can induce dramatic water level setup.•Flood-tide current velocities are increased and ebb-tide velocities are decreased.•Freshwater inflow into the North Branch of the Yangtze Estuary is decreased.•The Ekman transport from remote winds is the main mechanism.