With all eyes on the South Pacific in the lead up to the Olympic Games, it’s impossible not to notice the big purple blob of swell forecast to soon hit Tahiti.

At present, surfing's Olympic athletes are in Teahupoo preparing for the games. Yet as they familiarise themselves with the reef, a potent mix of weather is combining 3,000 kilometres to the southwest of them.

Yes, that purple blob.

In the coming days, a significant Southern Ocean frontal progression is set to develop south of New Zealand, squeezed by the near record-breaking high pressure system currently straddling southern Australia. 

It’s this squeezing between the high pressure system and polar westerly winds that will set in motion a swell that, from this vantage point, will invite comparison to the infamous Code Red swell from thirteen years ago - August 27, 2011, to be exact.

The driver will be a strong node of the Long Wave Trough (LWT) developing southeast of New Zealand. The Long Wave Trough is an upper atmospheric feature which effectively steers surface features, such as cold fronts, towards where it is amplified. 

With the LWT focussed southeast of New Zealand we’ll see Southern Ocean storms steered toward this region over the next week.

The undulation is the path of the Long Wave Trough, which storms broadly follow. Later this week the path of the Long Wave Trough will shift to be southeast of New Zealand setting up a corridor of swell aimed at Tahiti.

During today and tomorrow, an initial polar frontal system will generate a broad swathe of westerly gales south of New Zealand, setting in motion an active sea state.

An active sea state is essentially an agitated sea surface that works as a primer for any following storm, allowing wave growth to accelerate faster than it would off a placid sea state.

Over that active sea state, an even stronger frontal system will pass this weekend and early next week. With wind speeds expected to reach storm-force (55kt - 100km/h) as it moves past New Zealand’s East Coast, we’re expected to see open ocean seas reaching 45 feet, or 13.5 metres, aimed squarely at Tahiti.

It will arrive in Tahiti amid a week of large surf with the peak being either late on Wednesday 10th July or sometime on Thursday 11th - two weeks before the Games begin.

It'll create a spectacle only witnessed every few years. The surf will be in the 15 foot+ range - or five to six times overhead - and most definitely tow only. Quality of the surf will depend on local winds which we'll monitor closely over the coming days.

The image that came to define Code Red 2011 - Nathan Fletcher loses contact deep in the maw of Teahupoo (Brian Bielmann)

The Code Red swell of 2011 got its name from the signal used by Tahitian authorities to shut down any nautical activities for 24 hours. To date, it's only been exercised twice, the second time in July 2022, yet despite the bureaucratic stop sign, surfers have ridden waves at Teahupoo during both Code Red swells.

With the eyes of the world on the region, it’ll be interesting to see what sort of policing will be called upon if a third Code Red is announced.

There’s also the expected damage to local infrastructure due to the inundation of the Tahitian coast in such swells.

The Paris Olympics begin on Friday 26th July, with the waiting period for surfing beginning the very next day.

// CRAIG BROKENSHA