La Paz Swell Statistics, January: All Swell – Any Wind
This picture describes the variation of swells directed at La Paz over a normal January. It is based on 2124 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the most applicable grid node based on what we know about La Paz. In this particular case the best grid node is 57 km away (35 miles).
The rose diagram describes the distribution of swell sizes and swell direction, 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 happened only 5% of the time. Green and yellow represent increasing swell sizes and highest 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 occurs.
The diagram implies that the prevailing swell direction, shown by the longest spokes, was SSW, whereas the the dominant wind blows from the NE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from La Paz and out to sea. We combine 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 La Paz, you can load a different image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical January, swells large enough to cause surfable waves at La Paz 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.