Bauang Swell Statistics, July: All Swell – Any Wind
This picture describes the variation of swells directed at Bauang through a typical July. It is based on 1983 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the optimum grid node based on what we know about Bauang, and at Bauang the best grid node is 34 km away (21 miles).
The rose diagram describes the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These occurred 34% of the time. Green and yellow represent increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the dominant swell direction, shown by the largest spokes, was WSW, whereas the the dominant wind blows from the SSW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Bauang and out to sea. We group 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 surfable at Bauang, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average July, swells large enough to cause good for surfing waves at Bauang run for about 66% 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.