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

Best Days: South Coast tomorrow morning for the keen, later Wednesday possibly on the Mid Coast for the keen, Monday morning down South

Features of the Forecast (tl;dr)

• Small, fading mid-period S/SW swell tomorrow with N/NE tending E-E/SE winds
• Tiny Wed AM with fresh NE winds
• Inconsistent W/SW groundswell Wed PM to 1-1.5ft on the Mid, fading Thu
• Building W swell later Thu, peaking Fri with increasing W winds Thu and early W/NW tending SW winds Fri
• Weak SW swell for Fri PM down South, easing Sat with SW winds
• S/SW winds on Sun with a building S/SW swell, easing Mon with E/NE morning winds

Recap

Plenty of size for Saturday morning but average conditions with a S'ly wind down South, cleaner on the Mid Coast but with a drop in swell back to 1-1.5ft.

Yesterday was cleaner, smaller and peaky down South with a light cross-offshore wind and 3ft sets across Middleton, tiny and to 0.5-1ft on the Mid Coast.

This morning is similar across both coasts and for the keen down South.

This week and weekend (Sep 6 - 11)

Down, down down.

We've got a slow old forecast period ahead for the South Coast with the surf due to fade over the coming days as winds improve thanks to a strong high moving in slowly from the west.

A great N/NE offshore is due tomorrow morning but we're looking at fading 1-2ft sets out of the S/SW across Middleton, bumpy after lunch with E-E/SE sea breezes.

Wednesday morning will be tiny with a persistent, gusty NE breeze. A lay day down South. On the Mid Coast, a tiny inconsistent W/SW swell from the Indian Ocean may be seen with sets to 1-1.5ft but keep your expectations lowered.

Moving into Thursday and a mid-latitude low that's due to form west of the Bight tomorrow evening will push east while strengthening. A fetch of strengthening W/SW winds will project towards us on Thursday.

The only issue is that the European model which is generally more accurate has the low moving north on approach, aimed into the Eyre Peninsula, resulting in a smaller, weaker W'ly swell and lighter local winds on Thursday/Friday.

Being only a couple of days out, to have such divergence is rare so we'll have to check back on Wednesday for a much clearer idea on the expected size.

Clear model divergence for Wednesday evening. EC (top) has an average swell generating fetch for the Mid, GFS (bottom) is much better.

Basically, the windier it is, the bigger the swell will be and with lots of bump and chop on the Mid, though if winds are lighter Thursday we'll be looking at smaller, weaker surf.

At minimum we should see 1-1.5ft sets late Thursday through Friday, and maximum 2ft to nearly 3ft.

Either way Friday when the swell peaks onshore SW winds are likely, possibly W/NW for a period early down South. Looking at the South Coast and the W'ly energy won't get in and we rely on the backside of the low and local SW winds to whip up a weak SW windswell into the afternoon to 2-3ft.

Into the weekend the low will weaken and move east, bringing weaker SW winds and easing surf on Saturday. They won't be overly strong but with the weak nature of the swell it's not looking great.

Sunday looks average as winds freshen from the S/SW thanks to a polar front passing just south of us Saturday, then clearing to the east into Sunday and early next week, followed by a strong high.

This front should bring some new S/SW swell for later Sunday and Monday as winds swing more E/NE and then N/NE Tuesday. More on this and an update on the W/SW swell potential later Thursday/Friday on Wednesday.