Ajo Swell Statistics, Winter: All Swell – Any Wind
This picture shows the range of swells directed at Ajo over a normal northern hemisphere winter. It is based on 6931 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the most applicable grid node based on what we know about Ajo, and at Ajo the best grid node is 10 km away (6 miles).
The rose diagram illustrates the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 5% of the time. Green and yellow illustrate increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the prevailing swell direction, shown by the biggest spokes, was NW, whereas the the prevailing wind blows from the SW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Ajo and offshore. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are good for surfing at Ajo, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical northern hemisphere winter, swells large enough to cause clean enough to surf waves at Ajo run for about 95% of the time.
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.