Annascaul Rivermouth Swell Statistics, February: All Swell – Any Wind
This chart shows the variation of swells directed at Annascaul Rivermouth through an average February, based on 2102 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the most applicable grid node based on what we know about Annascaul Rivermouth. In this particular case the best grid node is 35 km away (22 miles).
The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 20% 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 commonly that size swell was forecast.
The diagram implies that the most common swell direction, shown by the largest spokes, was WSW, 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 Annascaul Rivermouth and offshore. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Annascaul Rivermouth, 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 February, swells large enough to cause surfable waves at Annascaul Rivermouth run for about 68% 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.