Agnes Waters Swell Statistics, July: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Agnes Waters that coincided with light winds or offshore conditions through a typical July. It is based on 2480 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 shows the largest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the most common swell direction, shown by the longest spokes, was E, whereas the the most common wind blows from the SSE. 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 15% of the time, equivalent to 5 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal July. Taking into account the fraction of these swells that coincided with expected 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 15% of the time and that surf is blown out by onshore wind 33% of the time. This is means that we expect 15 days with waves in a typical July, of which 5 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.