Army Beach Swell Statistics, Março: 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 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 illustrate increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. 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 biggest spokes, was NW, whereas the the prevailing 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 16% of the time, equivalent to 5 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal March but 7% of the time we expect swell in the range 2-3m (6.5-10ft) 7%, equivalent to (2 days). Taking into account the proportion 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 16% of the time and that surf is spoilt by onshore wind 53% of the time. This is means that we expect 21 days with waves in a typical March, of which 5 days should be clean enough to surf.
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.