South Australian Forecast by Craig Brokensha (issued Monday 19th December)

Best Days: Mid Coast Wednesday, both coasts Thursday morning, South Coast Friday morning, both coasts Monday

Recap

Poor onshore waves on the South Coast Saturday with tiny surf on the Mid.

Sunday was much better across both coasts with a light offshore wind down South and peaky workable waves at all breaks, while the Mid Coast saw a bit more size than expected with 1-1.5ft sets.

Today the swell was event straighter and cleaner down South with excellent waves across the swell magnets. The Mid was back to 0.5ft.

This week and weekend (Dec 20 – 25)

An onshore change due this evening will be linked to a weakening mid-latitude low passing south of us.

This low has been generating a moderate to large W/SW groundswell for the state, forming in the southern Indian Ocean last week and producing a fetch of W/SW gales.

The system is now weaker and moving south of the Bight, with a fetch of strong W/SW winds being aimed through our western swell window.

What we should see is small waves most of tomorrow, ahead of a late afternoon kick in size across the Mid from 1ft+ through the morning, to 2ft on the sets by dark.

A peak in size is due through Wednesday to 2ft to possibly 3ft on the favourable parts of the tide, smaller from 1-2ft Thursday morning.

The South Coast should peak Wednesday to 3-4ft off Middleton and 5-6ft at Waits and Parsons.

Winds aren't ideal, with a S/SW-SW breeze possible most of Wednesday, tending S/SE late. We could see a morning S/SE'ly though, tending SW and then reverting back to the S/SE late, so keep an eye on the local obs during the morning. The South Coast will see S/SW tending S/SE winds.

A more favourable E-E/NE breeze is likely to kick in across the South Coast Thursday as the swell eases from 3ft at Middleton.

Friday looks to offer the cleanest waves but small surf to 2ft off Middleton, while Waits and Parsons will be the go with a N/NE breeze before sea breezes kick in.

Conditions for the weekend are a little hard to pick at this stage with a couple of tricky surface troughs in the area.

We may see variable winds from the SE each morning, but no major swell.

An inconsistent W/SW groundswell is due Saturday but to no major size down South, while the Mid Coast may see 1ft sets.

Of greater importance is a better W/SW groundswell due early next week with favourable winds for both coasts, but more on this Wednesday.