The rose diagram shows only the swells directed at Longnook Beach that coincided with light winds or offshore conditions through a typical June and is based upon 1594 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 show increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In each 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 biggest spokes, was E, whereas the the dominant wind blows from the SW. 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 12% of the time, equivalent to 4 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal June. Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Longnook Beach is exposed to open water swells, we think that that clean surf can be found at Longnook Beach about 12% of the time and that surf is blown out by onshore wind 17% of the time. This is means that we expect 9 days with waves in a typical June, of which 4 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.