Awatoto Rivermouth Swell Statistics, August: Surf with Light or Offshore Winds
This image shows only the swells directed at Awatoto Rivermouth that coincided with light winds or offshore conditions through a typical August. It is based on 2480 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. Green and yellow show increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the most common swell direction, shown by the largest spokes, was ESE, whereas the the most common wind blows from the WNW. The chart at the bottom shows the same thing but without direction information. For example, swells larger than 1.5 feet (0.5m) coincided with good wind conditions 31% of the time, equivalent to 10 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal August but 8% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 8%, equivalent to (2 days). Taking into account the fraction of these swells that coincided with predicted offshore winds, and given the fact that Awatoto Rivermouth is exposed to open water swells, we calculate that clean surf can be found at Awatoto Rivermouth about 31% of the time and that surf is messed up by onshore wind 30% of the time. This is means that we expect 19 days with waves in a typical August, of which 10 days should be surfable.
IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.