South Australian Forecast by Craig Brokensha (issued Wednesday 7th June)

Best Days: Mid Coast later tomorrow, Friday, both coasts Saturday, South Coast Sunday through most of next week

Recap

Great waves across the Mid Coast yesterday with 2ft+ of W/SW swell holding all day with favourable winds.

Today the swell was still hanging in at 1-2ft on the sets across the Mid Coast, 1-1.5ft at most other breaks with straight offshore winds, while the South Coast saw improving conditions and easing waves from 3-4ft off Middleton.

This week and weekend (Jun 8 – 11)

The surf will continue to ease into tomorrow morning across both coasts and you'll have to brave the cold early down South as a dawn NW'ly will give into a S/SW change mid-morning.

Into the late afternoon the Mid Coast should start to see some new W/SW groundswell, generated by a strong polar frontal progression through the Indian Ocean and under WA, with the front linked to this swell bringing tomorrow's change as it passes under us.

We may see 1-1.5ft sets late with S'ly winds, but Friday is the day to surf.

Satellite observations have confirmed a great fetch of severe-gale to storm-force W/SW winds being projected through our western swell window and with this we should see the Mid Coast coming in at consistent 2-3ft from late morning, with Middleton due to kick to 3-5ft into the afternoon.

Unfortunately winds will be poor and fresh from the S/SE across the South Coast, but the Mid Coast should be good all day.

Over the weekend we'll see the W/SW swell ease, slowed across the South Coast but reinforcing SW swell energy from pre-frontal W/NW fetches swinging in from the Indian Ocean, under the country.

Winds will improve for the South Coast but conditions are still likely to be a little peaky Saturday with a morning E/NE-NE breeze. Middleton should ease from 3-4ft, with easing 2ft sets on the Mid Coast.

Sunday looks cleaner with a morning N/NE breeze, variable into the afternoon.

Into early next week some very inconsistent long-range W/SW groundswell is due to build Monday afternoon, easing Tuesday. This was generated in our far western swell window, south-east of South Africa and the wait between sets are due to be 10-15 minutes. Middleton should see 2ft to sometimes 3ft waves later Monday and early Tuesday, but of greater importance is a large and powerful mix of SW and W/SW groundswell due Wednesday/Thursday.

During this weekend a very significant storm is forecast to form in the Heard Island region (possibly reaching the specifications of a 'bombing low'), with a broad fetch of severe-gale W/SW winds generated with stronger core winds in the storm to hurricane-force range.

This low will project slowly east through our south-western swell window before weakening, only to spawn a secondary strong and more northern front. This will project a secondary broad fetch of severe-gale W/SW winds through our western swell window, with both swell events due to peak concurrently on Thursday morning.

The first super long-period SW groundswell is due to arrive through Wednesday though, building into the afternoon ahead of a peak Thursday.

We'll discuss the sizes in more detail on Friday but winds are looking excellent with N/NE offshores, but check back in a couple of days for the latest on this.