South Australian Forecast by Ben Matson (issued Wednesday March 12th)

Features of the Forecast (tl;dr)

• Small leftovers down south with light winds Thurs AM
• New swell arriving late Thurs, holding Fri with small waves on the Mid and better surf down south
• Fun smaller waves Saturday down south
• New long period groundswell building late Sat, peaking Sun, though will become spoiled by freshening onshores
• Stacks of swell for next week

Recap

The Mid saw small lines on Tuesday though nothing much more than a lazy foot. Better surf was found at Victor with clean 2ft surf building to 2-3ft at Middleton during Tuesday, with bigger surf at the swell magnets. Size has slowly eased today. Winds have been light for the most part, so conditions have been clean, though freshening S’lies kicked in mid-afternoon down south both days. 

This week (Mar 13 - 14)

Lingering S/SE winds are expected across the South Oz coast on Thursday. There won’t be much strength in it so conditions should be reasonable at Victor (though not great), and it’ll be ideal for the Mid Coast. Light variable winds and sea breezes are due Friday so any surface wobble we see Thursday (down south) should disappear for the last day of the working week.

As for surf, Thursday will start out very small but a new long period swell is expected to build during the afternoon, and will probably show best into the evening and/or early Friday morning. 

This swell will have been generated by a large, slow moving polar low well SW of WA earlier this week. However, this is a distant source so there’ll be very long breaks between the sets. 

We’re looking at a peak across the Middleton stretch around 2-3ft+ (bigger at the swell magnets) but the Mid Coast probably won’t reach much more than a lazy one foot. 

With the Cape du Couedic buoy still out of action, your best options will be to monitor the surfcams for signs of life after lunch. 

Expect an easing trend through Friday so aim for an early paddle for the most size. 

This weekend (Mar 15 - 16)

We’ve got a weekend of two halves on the way. 

Saturday looks nice and clean with light to moderate N/NE winds and initially small leftover groundswell from Friday. with perhaps some minor reinforcements from mid-range energy sourced from a pre-frontal W/NW flow sitting just ahead of a significant Southern Ocean low (see below), that’ll generate a solid swell for Sunday.

For the most part Saturday will be on the small side (0.5-1ft on the Mid, 2ft+ at Middleton), but late in the day the new swell should start to muscle in. 

Sunday’s looking at a peak in size around 4-5ft+ by late afternoon across the Middleton stretch, though gusty onshore winds are expected to kick in early as a strong front crosses the coast. So Victor will largely become blown out - early morning may offer a brief window of lighter winds, though probably only W’ly at best.

I’m not super keen on the swell direction for the Mid Coast and suspect we’ll see slow 1-2ft sets with perhaps some minor windswell loading on top if the onshore breeze gets above 20kts. Either way, early morning will have the best conditions of the day. 

I’ll fine tune these numbers on Friday. Regardless, aim for a Saturday session down south and a small grovel on the Mid on Sunday.

Next week (Mar 17 onwards)

No change to the outlook for next week, with a strengthening conveyor belt of Southern Ocean fronts expected to generate an extended period of elevated wave heights across the South Oz Coast from Sunday thru’ next Thursday or thereabouts.

Even better, the high pressure belt will probably remain in place across the coast, so - apart from Monday, which looks like it’ll be influenced by a vigorous frontal passage - most of next week should see relatively light winds, therefore spreading opportunities across more coastal regions. 

Either way we’ve got a great run of autumnal swell coming up for the entire state.