This image shows only the swells directed at Ehukai/Gums that coincided with light winds or offshore conditions over a normal northern hemisphere summer and is based upon 5066 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 illustrate increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was NNW, whereas the the most common wind blows from the E. 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 9% of the time, equivalent to 8 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal northern hemisphere summer but 2% of the time we expect swell in the range 2-3m (6.5-10ft) 2%, equivalent to (2 days). Taking into account the proportion of these swells that coincided with forecast offshore winds, and given the fact that Ehukai/Gums is exposed to open water swells, we think that that clean surf can be found at Ehukai/Gums about 9% of the time and that surf is blown out by onshore wind 1.0% of the time. This is means that we expect 9 days with waves in a typical northern hemisphere summer, of which 8 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.