Definitions for "Mean higher high water"
The arithmetic average of the elevations of the higher high waters of a mixed tide over a specific 19-year period. For shorter periods of observation, corrections are applied to eliminate known variations and reduce the result to the equivalent of a mean 19-year interval.
A tidal datum. The average of the higher high water height of each tidal day observed over the National Tidal Datum Epoch. For stations with shorter series, simultaneous observational comparisons are made with a control tide station in order to derive the equivalent datum of the National Tidal Datum Epoch.
The average height of the higher of the two high tides in the San Francisco Bay.