An Autumn Lament

Autumn is the great aquatic unifier.

Not just for Australian surfers but worldwide. Summer doldrums fade away and, almost universally, the ocean comes to life. Sure, it takes winter for things to really kick in across the high latitude storm belts which fire up dry season Indonesia and boreal winter Hawaii, but it's autumn when the switch gets flicked.

For sub-tropical NSW, where I reside, the autumn story is a good one. It goes something like this.

The tale begins in February, the last month of austral summer, when tradewinds reach their seasonal maximums and it's rare to see days below three feet. Coral Sea and South Pacific cyclones are on the menu - statistically most prevalent in February. Lots of surf, potentially punctuated by significant cyclone swells. The only downer for February are the large highs, which are responsible for the trade swells, driving constant south-east to east winds across the sub-tropics. Fine if you've got north-facing points to provide wind-protecting alignments, but generally keeping surf on the open stretches on the scrappy side. This February was straight out of the mold: barely a day below head-high and tons of scrappy surf, with high wave count sessions on offer if you didn't mind dodging armadas of bluebottles.

Sometime in late February or during early March, so the historical data goes, there's a noticeable relaxation in the onshore flow. Temperature gradients between warm ocean air and cooler overnight land masses sees morning land breezes becoming more common. Swells remain predominantly from the east, sometimes large if tropical cyclone swells from the Coral Sea and South Pacific make landfall. March would be counted as one of the more delightful months for surf on the North Coast.

Through April the morning offshores become ever more reliable. Tasman Sea swells from the south through east-southeast join the party, particularly if low pressure forms. Anzac Day represents a reliable seasonal shift marker to a more deep autumn phase, characterised by cooler temperatures and massive inshore migrations of fish and bird species, which have produced some of the most iconic images of North Coast autumns. Morning backlit point surf with surfers racing schools of mullet represented some of the most evocative depictions of what Alby Falzon termed in Morning of the Earth a “fantasy of surfers playing in nature's oceans”.

Autumn culminates in May. Large Tasman Sea swells are expected. Over two decades of data from the Tweed River Sand Bypass Project has confirmed anecdotal observations that sand transport peaks in May. Whatever damage was done to sandbanks by cyclones in February or March is redeemed in May. Banks get shallow and groomed and deep tubes become as common as a morning cup of coffee. By this stage cups are overflowing and crowds mellow out. In between swells, small quality waves can be unattended as surfers recharge for the next swell. That's the story of a traditional autumn.

Scenes from a traditional autumn (Steve Shearer)

Autumn 2025 was nothing like that. For the second February in a row there was an ominous sign registering across the North Coast buoy array with sea surface temperatures (SSTs) comfortably above the 26.5 needed to sustain a tropical cyclone. Alfred showed up as a tropical low on the 21st February north-east of Cooktown. Almost two weeks later it was sitting as a Category 2 tropical cyclone due east of the Queensland border, marinating in those soupy SST's and quite content to sit there before beginning a straight westerly track back towards South-East Queensland, eventually fading to a tropical low as it crossed the coast at Bribie Island on the 8th March.

No need to recount the epic swell bender at Kirra or the immense and prolonged swell bombardment across the sub-tropics. Beach erosion was patchy yet profound in areas but the damage to inshore sandbanks was almost universal. Banks that had been merely ordinary or bad were now non-existent. The Superbank was dragged halfway to Tugun, forming a large outer storm bar that became known as 'The Meadows'. A metre of rain in catchments of the Tweed and Richmond Rivers (1,146mm in Springbrook, 856mm in Mullumbimby) caused major flooding and severely degraded water quality, particularly in the Richmond where a blackwater event caused the death of millions of tons of fish.

The swell bender and images of Kirra captured the imagination of surf media, and rightly so, but Northern Rivers surfers knew the hangover from Alfred was going to be prolonged. Unlike any other tropical cyclone of recent decades it was the extended nature of the event as Alfred sat and stewed offshore which has caused the damage. No-one knew how long it would take for nearshore sand reservoirs to rebuild.

Like most of my peers I sat out the aftermath of Alfred. Memories were still fresh of local surfers being hospitalised by bugs from the 2022 floods, and the onshore wind, brown water, and poor surf were no inducement to brave the bacterial load. That took out the rest of March. The first month of autumn down and if you missed the Kirra days you were still at the starting line.

April tried. It really tried. The insane wet signal unleashed by Alfred showed signs of reversing back to norms but coastal troughs and onshores were there waiting with weeks of rain every time a sunny day with offshores showed up. We somehow missed scoring from the low which supplied 15 foot surf to Sydney and southern NSW. Onshore 4 foot rockrunners in the rain was the sum total of that event.

Good Friday was a classic swell with classic conditions, but in the absence of sand on the points wave quality was more like one of those classic nightmares. The ones where you try to run but somehow can't reach more than a slow, ungainly waddle. It could have been epic, it was barely mediocre.

Postcard from the Northern Rivers, 2025 (Steve Shearer)

May was a wet, soggy mess. Apart from the last week, it rained every day. Water quality went back to putrid and every swell went begging looking for a quality piece of sand to break on. The first 15 days were onshore. Of the 31 mornings in May, only 11 had westerly component wind.

Thousand yard stares became common on the point. Snippets of conversation were on the bleak side. Haven't surfed for three weeks. Played pickleball the other day. Fuck this, I'm moving south.

Now, three months post-Alfred, the sand still remains absent across almost all the quality sand bottom points in the region.

We take sand largely for granted but it represents a bathymetric paradox of vital concern for surfers.

Sand, by its nature, is individual - it's composed of grains - yet its power is in the collective. Each individual grain may be a magical artifact of geological time but for it to perform any meaningful bathymetric work in the surf zone we need millions of those grains and it needs to move and settle in unison. The collective nouns for the masses of sand required are unlovely. Laid down as a mass the sand is termed a 'slug'. In suspension with seawater it's a 'slurry'. Nothing is more loved, cherished, desired and studied in this neck of the woods than those slurries of sand when they are on the move and the final destinations of those slugs.

Freshly laid down across pointbreaks they transform wave quality with an immediacy that is shocking. Waves go from deep holes to unrideably shallow caves in a day. An 80 metre outside section breaking over rock turns into a 400 metre down the line miracle as the freshly laid slug turns swell energy into spinning tubes. They are truly a bathymetric miracle in the surfing world, one we probably take for granted in the age of the sand bypass mediated Superbank.

(Steve Shearer)

Conversely, you take the sand off a sand bottom point and you've got no surf spot. Or a vastly degraded one.

The slug delivery mechanism is not perfectly understood. We know that sometimes sand can trickle around points in modal wave conditions but it takes considerably more wave energy to create the suspended sand slurry and move the slug, usually from one side of a headland to the other. A sweet spot in wave energy and longshore sand transport is required. Too much and the existing bank is 'busted' and the sand slug is deposited on the storm bar or moved out of the area. Too little and there is insufficient energy to move and deposit the sand in the correct position.

Of course, there has to be upstream sand to move. In the post-Alfred eroded state, significant swell events from the south-east that had sufficient energy to transport a sand slug simply had no slugs available to transport. In the words of a local wag opining on the lack of sand: “there's nothing in the mail”.

What to make of this complete failure of an autumn across the North Coast points. Is this an anomaly we can just scratch off the score card or a new normal that requires explanation? I lean towards the latter.

As mentioned before, SST's well into NSW were sufficiently high to support a tropical cyclone for the last two summers, which is what came to pass when TC Alfred showed up. Warming in the Tasman Sea is occurring at twice the rate of the global average. SST's have been the highest or second-highest on record since July 24th.

Potential for destructive cyclones to not only provide days-long swell benders but massively erode inshore sand deposits needed for good surf is now a live reality. Where has all the sand gone from Alfred?  We simply don't know, nor on what time frame it will be available to rebuild destroyed sand banks.

As for the lack of typical autumn conditions, one of the strongest predictions about climate change has been an expansion of the Hadley Cells - the movement of heated air near the equator, which cools and descends near the sub-tropics - and a strengthening of the sub-tropical ridge. That ridge was a feature almost all autumn, usually in conjunction with a coastal trough. The result: days and weeks of onshore wind with relentless rain. Warmer water can hold more water vapour and the stronger onshore flow from the strengthened sub-tropical ridge is a more powerful engine to drive it ashore.

The effect isn't universal. Areas to the south of the ridge rejoiced in constant swell and good winds - an all-time autumn.

But the facts are now becoming clearer and the signal stronger. Seasonal norms in this part of the world are breaking down or becoming more exaggerated. Often to extreme and unreconisable levels. From winds, to sand flow, to size and duration of large swell events, to extreme rainfall, this autumn has shown that the old playbook no longer applies.

Our precious autumn is the season most under threat.

// STEVE SHEARER