Apache Pier Swell Statistics, October: All Swell – Any Wind
This image shows the variation of swells directed at Apache Pier through an average October and is based upon 2480 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the best grid node based on what we know about Apache Pier. In this particular case the best grid node is 39 km away (24 miles).
The rose diagram describes the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These occurred 36% 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 frequently that size swell was forecast.
The diagram suggests that the dominant swell direction, shown by the longest spokes, was SE, whereas the the prevailing wind blows from the N. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Apache Pier and away from the coast. We group these with the no surf category of the bar chart. To keep it simple we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Apache Pier, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical October, swells large enough to cause surfable waves at Apache Pier run for about 64% 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.