Was This XL UK Swell the Biggest of the Past 10 Years?

Tony Butt

by on

Updated 25d ago

Cover shot by Clare James Photography

If the Cribbar was situated on the North Shore of Oahu, it probably wouldn’t get much attention. But the Cribbar is in England, and big-wave spots in England aren’t exactly as abundant as they are in Hawaii. The Cribbar is probably England’s biggest surfable wave, and the fact that it only gets really good a few times a decade, makes it special, perhaps even legendary. Here we're going to talk about the recent swell of Feb 2 2021, and see how it compares with two others, namely Oct 30 2011, and Dec 16 2016.

And a quick caveat, while this recent session may not have been the biggest ever swell to hit humble UK shores, it certainly was one of the cleanest and coupled well with those favourable winds. Things like the Hercules storm sent colossal swell to England, but it was marred at some of the exposed beaches by gale force wind. So, we're looking at the above sessions because they're what stick out as having that magic combo of XL swell and fairly favourable winds.

Forecast: UK + Ireland

The reason the Cribbar is so fickle is that it needs a lot of factors to coincide. For a start, you need a big enough swell for it to break: anything under about eight or ten feet and it won’t break outside of the headland itself. Then, of course, the swell has to be clean and lined-up, not a raging storm driven by storm-force onshore winds.

For the swell to be big enough but lined-up at the same time, a low pressure needs to track across the North Atlantic from west to east, and intensify while it is still a long way from the coast. Ideally, the system will weaken or veer away before it gets too close, so that the long-period swell isn’t contaminated by locally-generated short-period swell, and so that local winds have a chance of being light offshore or very light crosshore. Otherwise, the Cribbar won’t be realistically surfable.

The Cribbar is a finger of reef extending off Towan Head in Newquay. West swells are focused onto the reef, with the focusing being more intense with long-period swells.

The Cribbar is a finger of reef extending off Towan Head in Newquay. West swells are focused onto the reef, with the focusing being more intense with long-period swells.

The tides are really important as well. To give the Cribbar a better chance of breaking for longer during daylight hours, you need a fairly big low tide around the middle of the day. In Cornwall, when the tides are springs, low water occurs around midday, which is lucky. But who is to say that the right swell and wind conditions won’t occur during neap tides, with puny low waters at either end of the day. Unless the swell is truly humungous, the tide might never get low enough for the Cribbar to break.

Animated swell chart for 2011.

Animated swell chart for 2011.

Our at-a-glance swell chart for 2011.

Our at-a-glance swell chart for 2011.

Anyway, let’s see how the recent swell compares with two others. The general long-term pattern over the North Atlantic was similar for all three swells. For example, the upper airstream was shifted quite far south, which made the lows themselves track further south and pump swell into mid areas such as Cornwall. Also, the upper airstream was very strong as it exited from the North American continent out into the Atlantic, which made the lows intensify right at the beginning of their trajectory, on the far side of the Atlantic. As a result, all three swells arrived lined up and with exceptionally long periods.

How it Happened: Biggest UK Swell Ever?

However, there were also a few differences in the paths of the lows. For example, the 2011 system travelled in almost a straight line between Nova Scotia and Ireland, reaching peak strength north of the Azores. The 2016 system also peaked north of the Azores, but then drew an upwards arc, swinging northwards towards Iceland. But the behaviour of the 2021 system was the most unique of the three: it deepened explosively while it was still way over on the other side of the Atlantic, then peaked northwest of the Azores with much bigger open-ocean wave heights than the other two. It continued on towards Ireland in a more or less straight line, and then, before making landfall, suddenly swung south into Biscay.

Animated swell chart for 2016.

Animated swell chart for 2016.

Our at-a-glance swell chart for 2016.

Our at-a-glance swell chart for 2016.

There were also some differences once the waves arrived at the Cribbar reef itself. In 2011, the swell was bigger, but the wind was much stronger than the other two. In 2016, the swell was slightly smaller, but wind conditions were much better. In 2021, the offshore wave heights weren’t much different to 2016, but the periods were extremely long, hitting 25 secs at the beginning, and still around 19 secs at the wave-height peak. This gave an extra punch to the swell and would have made individual breaking wave heights bigger due to the focusing effect of the reef. In addition, local wind conditions for the 2021 swell were very good for most of the day. Finally, all three swells coincided with spring tides, with low water occurring between about 13:00 and 14:00.

Animated swell chart for 2021.

Animated swell chart for 2021.

Our at-a-glance swell chart for 2021.

Our at-a-glance swell chart for 2021.

In summary, the set of circumstances that came together for each of the three swells was rare. But the swell of 2nd Feb 2021 was even rarer – from the behaviour of the upper airstream over the north American continent, to the veering away of the storm at the last minute, resulting in a large, super-long period west swell with light offshore winds, on a day with low tide just after lunch.

The Cribbar has worked many more times than this over the years, and not always been ridden. If you know of a swell that was bigger and cleaner than this one, let us know and we’ll look into it.

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