Anna Bay-Morna Point Swell Statistics, September: Surf with Light or Offshore Winds
This image shows only the swells directed at Anna Bay-Morna Point that coincided with light winds or offshore conditions through a typical 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. Green and yellow represent increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the dominant swell direction, shown by the longest spokes, was ESE, whereas the the prevailing wind blows from the NW. 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 13% of the time, equivalent to 4 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal September but 11% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 11%, equivalent to (3 days). Taking into account the fraction of these swells that coincided with forecast offshore winds, and given the fact that Anna Bay-Morna Point is slightly protected from open water swells, we estimate that clean surf can be found at Anna Bay-Morna Point about 13% of the time and that surf is messed up by onshore wind 22% of the time. This is means that we expect 10 days with waves in a typical September, of which 4 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.