Supertubos Unofficial Forecast

Portugal’s premier beach break tube offers forecasters a significantly more interesting challenge than South West France for the forthcoming Moche Rip Curl Pro. It’s anything but a typical beachbreak and requires an understanding of its complex bathymetry, hugely variable wave climate and tricky coastal winds. Here’s what we’ve learnt making the call.

Everything is key

It was relatively easy to cook up some ideal numbers for the Hossegor beachbreaks. Whilst direction will influence the way they break, it has a marginal impact on size. Reducing the equation to swell height and period, plus past experience, quickly dials you in. Supertubos is another beast altogether. The Cabo Carvoeiro to the North provides both obstruction, but also bathymetry which allows for significant refraction. If you’ve been reading up on your surf science you’ll be aware that this refraction is dependent on the period of the incoming swell. Longer period waves ‘feel’ the contours of this headland in deeper water and as a result slow and bend more than shorter period waves. Although the waves will bend the initial swell direction still matters. A lot.

For example push the period up to 18 seconds and even at 340 degrees a 6ft swell can show on the beach. Move down in period but put in some raw power and a 10ft@16 second swell can pump from the same northerly angle – more so than an 8ft@14 second swell from just north of west. To speed up our competition call we created charts and data for every possible scenario, calculating propagation in detail over the complex local bathymetry.

Wind is equally complicated. It’s far from unusual for the same storm systems that deliver swell to flirt with the coast bringing disruptive winds. Typically from the west or south these are tolerable on breaks to the north but offer no good news for Supertubos. Autumn also brings the tendency for an afternoon onshore breeze kicked up by a relatively cool ocean and warm land, albeit with the opposite effect often providing a morning of good offshore conditions. The coastline makes predicting this convection wind and its interplay with the larger scale synoptic wind almost a magic art and one that's hard to get right even with high resolution modelling.

Wave climate

While these subtleties aren’t unique, they’re coupled with one of the most variable wave and wind climates on the planet. With unobstructed fetch from Iceland to Brazil, the Peniche area will pick up anything the Atlantic throws at it and in October that can mean a huge amount of swell. We’ll regularly see numbers during the contest window that would put the Big Wave World Tour in the water. In fact the largest waves in the world are now being surfed just 20 miles to the North, amplified by the constructive interference created when these monster swells hit the deep water canyon at Nazare. Either side of these incredible swells we might have a run of conditions that’ll do little more than tickle the average beachbreak into life. Think back to 2009: 4ft@12 to 19ft@15 seconds within 24 hours – too small for interesting competition one day and contest site destroyed and tow-ins in the shelter of the harbour wall the next.

The right kind of sand

Once the swell finds its way to the beach, Supertubos' distinctive lip pitching ferocity is shaped by a small area of just the right kind of sand. The slope of a surfing beach is dictated largely by the size of the sand grains, itself dictated by the geography of the area. Fine sand is piled up by the incoming wave, then washed back as the spill retreats leaving a gently sloping foreshore. Coarser particles are washed up by the surf, but the water can then escape in part by draining back through the sand. This subtle interplay of sand and current leaves the steeper beach we need for barreling waves and, fortunately for competition, this small stretch of beach is a geographic anomaly in the region, offering perfect sand for super tubes.

Contest headache

If you’re planning a trip to Peniche there’s good news – the same headland Which obstructs Supertubos to the north offers a number of great north facing beaches with a variety of different waves. The smallest swells can kick up great beachbreak conditions at Belgas. The rock promontory at Lagide can moderate mid-sized swell from the north west and Molhe Leste can be ridden in almost the largest conditions the Atlantic can throw at it. This variety also gives shelter from the often strong winds that can occur as ocean storm systems affect the coast. Bottom line: you’ve got as good a chance of surfing every day here as anywhere in Europe.

For contest things are trickier. While in the past it has, technically, been mobile, in practice no one has wanted to carry the effort and expense of relocating miles to the north to beachbreak surf that, whilst decent, is unlikely to mesh with the idea of ‘the worlds best surfers in the worlds best waves’.

This throws up a conundrum. A world tour event in an incredibly consistent area but tied physically and emotionally to a spot that’s tricky to call, beset by variable and often unfavourable winds and somewhat fickle in the direction and period of swell needed to really light it up.

Falling as it does second to last in the tour schedule this event is always tense on the ground. World titles hang in the balance and requalification is still possible for those facing the cut. Supers typifies the paradox of a location where even increasing quality can mean an increasingly uneven playing field for competition. That’s before you add in the propensity for tide and convection winds to shorten the surfable day.

Of all the events on tour this is the one which most frequently takes organisers to the line looking for the right conditions. A situation that, in the past, has tested their resolve. It’ll be interesting to see if the new look tour is more prepared to use the mobile facility to manage these challenges – it should. It's not that dissimilar to the Quik Pro / La Graviere infatuation, and a move slightly further north there to a more consistently contestable bank doesn't look such a bad call with hindsight. That said 2011 saw stars align for a flawless two and a half days of competition in near perfect waves. Luck, as always, part of the surfing experience.

The surf outlook

A week from the start of competition we’re a long way out for detail. However European atmospheric models agree with the GFS we use for our principle forecasts. It looks likely that the start of competition will be on the back of a run of blocking high pressure over the Azores that’ll mean modest swell to start with. Around the 10 day mark (a few days into the window) we could see things start to return to life. The detail of this is likely to change but a slow start to competition looks possible with things hotting up into the following weekend - although the details at this range have been changing rapidly at this stage.