South Australian Surf Forecast by Craig Brokensha (issued Friday September 3rd)

Best Days: Mid Coast for the keen tomorrow afternoon and early Sunday, South Coast early tomorrow morning, South Coast Tuesday, Wednesday and Thursday

Features of the Forecast (tl;dr)

• Reinforcing W/SW groundswell building tomorrow PM with early variable winds on the Mid Coast, tending fresh S'ly, light W/NW down South, tending fresh S'ly
• Easing W/SW groundswell Sun with fresh S/SW tending SW winds (likely S/SE early on the Mid)
• Low point in swell Mon with W/NW tending SW winds 
• Mod-large SW groundswell building Tue, peaking in the PM with light WNW tending S/SW winds down South, variable on the Mid
• Easing mix of swells Wed with N/NW tending NW winds down South (N/NE early on the Mid), easing Thu with strong N/NW winds

Recap

It looked like all the size was seen into Wednesday across both coasts, with the stronger groundswell energy for yesterday coming in a bit smaller than expectations, more to 3ft+ across Middleton and 2ft on the Mid Coast but with choppy conditions.

Winds shifted from N/NE to N/NW down South switching up options (choppy on the Mid), while an evening change moved through, leaving variable winds and fun 2ft sets on the Mid Coast this morning (owing to a reinforcing W/SW groundswell), and 3ft on the sets across Middleton.

Good surf early this AM

This weekend and next week (Sep 4 - 10)

There's a window of lighter winds due across the South Coast tomorrow morning from the W/NW ahead of a S'ly change as a ridge of high pressure moves in from the west. We'll fall in between swells though with smaller 2-3ft waves across Middleton. The Mid Coast looks to be back to 1-1.5ft, and with similar variable winds before freshening from the S'th.

Into the afternoon, our new W/SW groundswell is due to fill in generated by the final frontal system in the progression linked to the last few days of swell. This was a broad, strong polar front projecting north-east towards Western Australia and it should kick the Mid Coast back to the 2ft range through the afternoon, with 3-4ft sets across Middleton.

The swell is expected to ease through Sunday with moderate to fresh S/SW tending SW winds (likely S/SE early on the Mid Coast).  Easing 2ft sets are due on the Mid Coast, 3ft+ down South.

We'll start to see the high pressure ridge moving in and across us early next week, swinging winds back around to the W/SW-SW generally, but the Victor region should see a period of W/NW winds but further drop in swell from 2ft across Middleton.

Tuesday and Wednesday are much better with variable winds due on the Mid Coast most of the day (weak sea breezes) and W/NW tending light to moderate S/SW winds down South. This will be along with a strong, new, building SW groundswell.

The source of this swell is a strong polar low that formed around the Heard Island region last night. This low will move slowly east through our swell window over the coming days, generating severe-gale W/NW winds, weakening to the gale-force range south of Western Australia Saturday evening.

This should produce a moderate to large SW groundswell that's due to arrive overnight Monday, building Tuesday ahead of a peak into the afternoon. Middleton should see 4-5ft waves, if not for the odd sneaky bigger cleanup into the afternoon, with the Mid Coast only coming in at 1-1.5ft.

A reinforcing pulse of additional swell from a secondary strong front firing up on the tail of the initial low looks weaker now, with the swell just slowing the easing trend into Wednesday.

Conditions are looking great for the South Coast Wednesday with N/NW tending NW winds (N/NE on the Mid) with easing 1-1.5ft sets on the Mid Coast and 4ft sets across Middleton, easing through the day.

Thursday will see stronger N/NW winds as the swell continues to ease. Longer term there's plenty more swell activity on the cards for next weekend, but we'll have a closer look at this Monday. Have a great weekend!