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 over a normal southern hemisphere winter. It is based on 7200 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 show increasing swell sizes and highest 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 prevailing swell direction, shown by the largest spokes, was SE, whereas the the dominant 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 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 think that that clean surf can be found at Barre de Balizas about 29% of the time and that surf is blown out 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.