Statistiques de Houle pour Agnes Waters, Mars: Vagues avec Vents Légers ou Favorables.
This image shows only the swells directed at Agnes Waters that coincided with light winds or offshore conditions over a normal March. It is based on 2220 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 represent increasing swell sizes and red represents largest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the dominant swell direction, shown by the largest spokes, was E, whereas the the most common wind blows from the ESE. 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 6% of the time, equivalent to 2 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal March. Taking into account the proportion of these swells that coincided with forecast offshore winds, and given the fact that Agnes Waters is exposed to open water swells, we calculate that clean surf can be found at Agnes Waters about 6% of the time and that surf is blown out by onshore wind 68% of the time. This is means that we expect 23 days with waves in a typical March, of which 2 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.