The figure shows the variation of swells directed at The Cove at Sandy Hook through a typical March. It is based on 1723 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 best grid node based on what we know about The Cove at Sandy Hook. In this particular case the best grid node is 41 km away (25 miles).

The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These happened only 57% of the time. Green and yellow represent 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 happens.

The diagram suggests that the prevailing swell direction, shown by the longest spokes, was SSE, whereas the the prevailing wind blows from the NW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from The Cove at Sandy Hook and away from the coast. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at The Cove at Sandy Hook, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average March, swells large enough to cause clean enough to surf waves at The Cove at Sandy Hook run for about 18% 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.