Mean Low Water Neaps (MLWN) (MLWN)

The average height of the two successive low waters during neap-tide periods at a stated location and over a defined observation period.

MLWN is a local tidal datum associated with smaller astronomical tidal ranges. Neaps arise primarily because solar and lunar tide-generating effects are partly opposed, not because their gravitational attraction simply becomes weaker. The value is an average rather than the level of every neap low water and must be interpreted with the authority’s datum and method. Weather, river flow and other non-astronomical effects can change the observed level.