A Street Swell Statistics, Janeiro: Surf with Light or Offshore Winds
This image shows only the swells directed at A Street 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 represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. Green and yellow show increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the most common swell direction, shown by the longest spokes, was SE, whereas the the most common wind blows from the WNW. 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 1.4% of the time, equivalent to 0 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal January. Taking into account the ratio of these swells that coincided with expected offshore winds, and given the fact that A Street is slightly protected from open water swells, we estimate that clean surf can be found at A Street about 1.4% of the time and that surf is spoilt by onshore wind 0.6% of the time. This is means that we expect 1 days with waves in a typical January, of which 0 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.