The rose diagram shows only the swells directed at Morro Negrito that coincided with light winds or offshore conditions over a normal March. It is based on 1724 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 red illustrates highest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the most common swell direction, shown by the biggest spokes, was SSW, whereas the the dominant wind blows from the N. 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 80% of the time, equivalent to 25 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal March but 14% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 14%, equivalent to (4 days). Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Morro Negrito is exposed to open water swells, we calculate that clean surf can be found at Morro Negrito about 80% of the time and that surf is messed up by onshore wind 20% of the time. This is means that we expect 31 days with waves in a typical March, of which 25 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.