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Piha-The Ditch ratings
Quality on a good day: 3.0
Consistency of Surf: 3.0
Difficulty Level: 3.0
Crowds: 3.0

Overall: 3.2

See all 18 ratings

Based on 3 votes. Vote

Surf Report Feed

Piha-The Ditch Swell Statistics, March: All Swell – Any Wind

The rose diagram describes the range of swells directed at Piha-The Ditch over a normal March. It is based on 2716 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the best grid node based on what we know about Piha-The Ditch. In the case of Piha-The Ditch, the best grid node is 6 km away (4 miles).

The rose diagram illustrates the distribution of swell sizes and directions, 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 2% of the time. Green and yellow show increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how often that size swell was forecast.

The diagram indicates that the most common swell direction, shown by the biggest spokes, was WSW, whereas the the dominant wind blows from the SSE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Piha-The Ditch and offshore. We group these with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Piha-The Ditch, 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 March, swells large enough to cause surfable waves at Piha-The Ditch run for about 98% 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.