Akito River Mouth and Reef Swell Statistics, Janeiro: Surf with Light or Offshore Winds
This image shows only the swells directed at Akito River Mouth and Reef 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 highest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the dominant swell direction, shown by the longest spokes, was SE, whereas the the dominant wind blows from the NNW. 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 24% of the time, equivalent to 7 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal January but 10% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 10%, equivalent to (3 days). Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Akito River Mouth and Reef is exposed to open water swells, we think that that clean surf can be found at Akito River Mouth and Reef about 24% of the time and that surf is messed up by onshore wind 35% of the time. This is means that we expect 18 days with waves in a typical January, of which 7 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.