A Street Swell Statistics, Dezembro: Surf with Light or Offshore Winds
This image shows only the swells directed at A Street that coincided with light winds or offshore conditions through a typical December. It is based on 2457 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 red illustrates the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the most common swell direction, shown by the longest spokes, was SE, whereas the the dominant wind blows from the NE. 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 4% of the time, equivalent to 1 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal December. Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that A Street is slightly protected from open water swells, we calculate that clean surf can be found at A Street about 4% of the time and that surf is spoilt by onshore wind 2.0% of the time. This is means that we expect 2 days with waves in a typical December, of which 1 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.