Del Mar Jetties Surf Stats

This chart shows the variation of swells directed at Del Mar Jetties through an average September, based on 2880 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the optimum grid node based on what we know about Del Mar Jetties. In the case of Del Mar Jetties, the best grid node is 26 km away (16 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast only 70% of the time. Green and yellow show 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 commonly that size swell was forecast. The diagram implies that the most common swell direction, shown by the longest spokes, was WSW, whereas the the prevailing wind blows from the W. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Del Mar Jetties and away from the coast. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are good for surfing at Del Mar Jetties, you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical September, swells large enough to cause clean enough to surf waves at Del Mar Jetties run for about 30% of the time.

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