South Australian Forecast by Craig Brokensha (issued Wednesday 5th August)

Best Days: South Coast today and tomorrow morning, desperate surfers Mid Coast Friday, South Coast Monday morning and Tuesday

Recap

Poor conditions across the South Coast yesterday with a large S/SW groundswell filling in through the day ranging between 4-6ft across most breaks down South. The Mid was a bumpy 1-1.5ft, tiny into the afternoon.

Today conditions are cleaner across all coasts but very cold owing to the polar air mass moving over us, with tiny and unsurfable waves on the Mid Coast, a cleaner though lumpy 4ft on the sets down South.

This week and weekend (Aug 6 - 9)

Make the most of today and tomorrow morning on the South Coast, as from tomorrow afternoon we'll see poor conditions with strong onshore E/SE-SE winds kicking in.

This will be linked to a mid-latitude low moving in from the north-west, deepening as it squeezes a strong high to our south.

This will occur through tomorrow and more so Friday/Saturday, but ahead of this a morning E/NE-NE breeze is due down South with a further drop in size from today. Middleton looks to ease back from 2-3ft or so out of the S'th, with a bit more size on the exposed beaches, but with the southerly direction, not as much as normally seen. The Mid Coast will remain tiny.

Later in the day but more so Friday a new W/SW tending SW groundswell is expected across the state, produced by a strong polar low that developed south-west of Western Australia. A fetch of severe-gale W'ly winds were generated, with the low weakening and now traversing the polar shelf through our southern swell window.

While possibly being seen later Thursday a peak is due Friday with infrequent 1-1.5ft sets likely on favourable parts of the tide across the Mid Coast and strong but inconsistent 4-5ft waves across Middleton.

Winds will strengthen from the E/SE tending SE on Friday only favouring the Mid Coast with SE tending S/SE winds on Saturday as the groundswell eases. With these winds we'll also see poor levels of S/SE windswell across the South Coast, persisting Sunday with strong SE breezes.

Come Monday we'll likely see winds swing back to the NE with another approaching mid-latitude low from the west, and some reinforcing S/SW groundswell is on the cards for the South Coast owing to persistent fetches of polar W/NW gales through our swell window.

Size wise Monday should be around 3ft across Middleton, with a mix of weaker but easing S/SE windswell to a similar size, cleaner Tuesday with a fresher N/NW breeze but small 2ft wave.

The outlook beyond this is unclear as the models diverge on the shape, track and intensity of the incoming mid-latitude system. With this it's not worth speculating beyond Wednesday at the outlook for later next week. Check back Friday for more details.