Agnes Waters Swell Statistics, Winter: Surf with Light or Offshore Winds
This image shows only the swells directed at Agnes Waters that coincided with light winds or offshore conditions over a normal southern hemisphere winter and is based upon 7266 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow represent increasing swell sizes and red represents biggest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the prevailing swell direction, shown by the largest spokes, was E, whereas the the prevailing wind blows from the SE. 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 16% of the time, equivalent to 15 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal southern hemisphere winter. Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that Agnes Waters is exposed to open water swells, we think that that clean surf can be found at Agnes Waters about 16% of the time and that surf is messed up by onshore wind 36% of the time. This is means that we expect 47 days with waves in a typical southern hemisphere winter, of which 15 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.