Average height of the highest one-third of the WAVES for a stated interval of time.
Defined traditionally as the mean height of the highest third of the waves, but now usually defined as four times the root-mean-square of the surface elevation (or equivalently as four times the square root of the first moment of the wave spectrum).
The average height of the highest 33% of all waves in a swell train or in a wave generating region. It also approximates the value an experienced observer would report if visually estimating sea height. This is the predicted height given in the Coastal Waters Forecast.
The generation of waves on water results not in a single wave height but in a spectrum of waves distributed from the smallest capillary waves to large waves indeed. Within this spectrum there is a finite possibility of each of the wave heights to occur with the largest waves being the least likely. The wave height most commonly observed and forecast is the significant wave height. This is defined as the average of the one third highest waves. The probability of encountering such a wave is about 1 in 10 while 1 in 1000 waves will be nearly double the significant wave height or higher
(Hs,Hmo, H 1/3) - This is the average of the highest 1/3 of all waves in a time series. It can be closely approximated from a time series of wave heights as four times the standard deviation of the time series. The value can also be approximated from four times the square root of the area under the energy spectrum of a FFT analysis. This is typically called Hmo.
The mean or average height of the highest one third of all waves in a swell train or in a wave generating region. It also approximates the value an experienced observer would report if visually estimating sea height.
The average wave height of the one-third highest waves of a given wave group.
The average height (trough to crest) of the 1/3rd highest waves. An experienced observer will most frequently report the highest 1/3rd of the waves observed.
Significant Wave Height, also known as SWH or Hs, is the average height (trough to crest) of the largest one third of waves. A well developed significant wave is approximately four times the standard deviation from sea level.