Augusta Rivermouth Swell Statistics, Settembre: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Augusta Rivermouth that coincided with light winds or offshore conditions over a normal September. It is based on 2400 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. Green and yellow represent increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the dominant swell direction, shown by the longest spokes, was SSW, whereas the the dominant wind blows from the WSW. 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 7% of the time, equivalent to 2 days. Open water swells exceeding >3m (>10ft) only happen 4% of the time in a typical September, equivalent to just one day. Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Augusta Rivermouth is slightly protected from open water swells, we think that that clean surf can be found at Augusta Rivermouth about 7% of the time and that surf is blown out by onshore wind 15% of the time. This is means that we expect 7 days with waves in a typical September, of which 2 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.