Statistiques de Houle pour San Miguel - Areias, Janvier: Vagues avec Vents Légers ou Favorables.
This image shows only the swells directed at San Miguel - Areias that coincided with light winds or offshore conditions over a normal January. It is based on 2372 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 red illustrates the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the prevailing swell direction, shown by the biggest spokes, was NW, whereas the the prevailing wind blows from the WSW. 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 28% of the time, equivalent to 9 days. Open water swells exceeding >3m (>10ft) only occur 4% of the time in a typical January, equivalent to just one day but 17% of the time we expect swell in the range 2-3m (6.5-10ft) 17%, equivalent to (5 days). Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that San Miguel - Areias is slightly protected from open water swells, we think that that clean surf can be found at San Miguel - Areias about 28% of the time and that surf is messed up by onshore wind 44% of the time. This is means that we expect 22 days with waves in a typical January, of which 9 days should be clean enough to surf.
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.