Barre de Balizas Swell Statistics, Winter: Surf with Light or Offshore Winds
This image shows only the swells directed at Barre de Balizas that coincided with light winds or offshore conditions through a typical southern hemisphere winter and is based upon 6538 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 largest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the dominant swell direction, shown by the biggest spokes, was SE, whereas the the most common wind blows from the W. 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 31% of the time, equivalent to 28 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal southern hemisphere winter but 3% of the time we expect swell in the range 2-3m (6.5-10ft) 3%, equivalent to (3 days). Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Barre de Balizas is exposed to open water swells, we calculate that clean surf can be found at Barre de Balizas about 31% of the time and that surf is messed up by onshore wind 43% of the time. This is means that we expect 67 days with waves in a typical southern hemisphere winter, of which 28 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.