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 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 illustrate increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In both graphs, 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 largest spokes, was SE, whereas the the prevailing 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 29% of the time, equivalent to 26 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise 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 ratio of these swells that coincided with expected offshore winds, and given the fact that Barre de Balizas is exposed to open water swells, we estimate that clean surf can be found at Barre de Balizas about 29% of the time and that surf is messed up by onshore wind 42% of the time. This is means that we expect 65 days with waves in a typical southern hemisphere winter, of which 26 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.