Army Beach Swell Statistics, July: Surf with Light or Offshore Winds
This image shows only the swells directed at Army Beach 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow represent increasing swell sizes and red shows the highest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the prevailing swell direction, shown by the longest spokes, was NW, whereas the the dominant wind blows from the ENE. 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 0.6% of the time, equivalent to 0 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal July. Taking into account the ratio of these swells that coincided with forecast offshore winds, and given the fact that Army Beach is exposed to open water swells, we calculate that clean surf can be found at Army Beach about 0.6% of the time and that surf is messed up by onshore wind 5% of the time. This is means that we expect 2 days with waves in a typical July, 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.