Jacks Hole Surf Stats

The rose diagram shows the range of swells directed at Jacks Hole through a typical September. It is based on 3358 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coast so we have chosen the best grid node based on what we know about Jacks Hole. In this particular case the best grid node is 9 km away (6 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened 62% of the time. Green and yellow represent increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell happens. The diagram suggests that the most common swell direction, shown by the longest spokes, was S, whereas the the prevailing wind blows from the WSW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Jacks Hole and out to sea. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Jacks Hole, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average September, swells large enough to cause surfable waves at Jacks Hole run for about 10% of the time.

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