A tide in which both semidiurnal and diurnal constituents are significant, so the two daily highs differ in height, the two lows differ, or both. The US Pacific coast, Hawaii and much of Alaska have mixed tides, which is why their tables list higher high, lower high, higher low and lower low waters. Mixed tides are subdivided as mainly semidiurnal or mainly diurnal on the basis of the form factor.
Mixed tide on the coast here, so read the table carefully, the morning low is barely a low at all.
Also heard as
- mixed semidiurnal tide
- mixed diurnal tide
Related terms
Semidiurnal tide
A tide with two high waters and two low waters of similar height in each lunar day.
Diurnal tide
A tide with a single high water and a single low water in each lunar day.
Diurnal inequality
How much the day's two high waters, or its two low waters, differ in height from each other.
Form factor
A ratio of diurnal to semidiurnal constituent amplitudes used to classify a tide as semidiurnal, mixed or diurnal.
Higher high water
The taller of a tidal day's two high waters, the one that matters most on mixed-tide coasts.