The rose diagram shows only the swells directed at Sentinel that coincided with light winds or offshore conditions over a normal February and is based upon 1584 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. Green and yellow illustrate increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In both graphs, 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 longest spokes, was SSW, whereas the the prevailing wind blows from the NE. 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 0% of the time, equivalent to 0 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal February. Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Sentinel is quite sheltered from open water swells, we think that that clean surf can be found at Sentinel about 0% of the time and that surf is blown out by onshore wind 0% of the time. This is means that we expect 0 days with waves in a typical February, of which 0 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.