South Australian Surf Forecast by Ben Matson (issued Monday 21st October)

Best Days: Tues/Wed/Thurs: nice waves at Victor. Wed/Thurs: small and fun though very inconsistent swell on the Mid, clean Wed but winds are a risk Thurs. Fri: stormy options on the Mid, easing Sat. Sun: improving both coasts with  easing swells. Next week: more long range swells.

Recap: Saturday was large and onshore across both coasts, but Sunday delivered rapidly improving options with lighter winds at Victor and light offshores on the Mid. Surf size peaked around 6-8ft down south and 3ft+ along the Mid, and this morning has remained clean with light offshore winds on both coasts and strong though easing swells from 4-5ft at Middleton and 2ft along the Mid Coast.

Triggs looking really nice Sunday morning - set wave sequence

This week (Oct 22 - 25)

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Tomorrow is looking great across the Victor stretch. 

Declining size from today means the Mid Coast will be well and truly into grovel territory (actually, it’s already there now) but with winds remaining light out of the NE, we’ll see clean conditions down south and there’ll be quality options across the Middleton stretch (3ft, inconsistent and easing) with larger, punchier surf around at Waits and Parsons. 

On Wednesday morning, the Cape du Couedic wave buoy will pick up the leading edge of a long range groundswell, generated over the last few days from an unusually stationary sequence of lows out near Heard Island. It’s a real shame that this pattern was so far from the mainland, as the swell will be of very high quality - but once it reaches South Australian longitudes it’ll be greatly diminished in size and consistency. 

Nevertheless, we’re looking at some really nice waves across the coast as the swell fills in, and the W/SW direction will also favour the Mid Coast. 

The bulk of the swell will be located some ~18 hours behind the leading edge (so, Thursday is a better chance for the most size), but late Wednesday afternoon should see a slow and inconsistent but otherwise reasonably building trend before the Thursday plateau is reached. The more favourable parts of the tide should pick up 2ft, almost 2-3ft sets on the Mid Coast though the swell direction will probably cap the South Coast around 3ft+ at Middleton. 

Conditions look best Wednesday with generally light NE winds and afternoon sea breezes, but Thursday has a risk that early N/NE winds will pick up and trend N/NW during the day. Of course, this is fine for the South Coast but may otherwise spoil proceedings on the Mid Coast.

Thursday’s northerly breeze will precede a cold front expected to cross the coast later Friday, so we’ll see strengthening W/NW winds ahead of a late W’ly thru’ W/SW change. 

As it is, the earlier stages of this front - immediately south-west of WA on Tuesday - will have been in the form of an intense cut-off low, with core winds up to 50kts (see below). This will kick up a concurrent groundswell that should produce 3-4ft waves on the Mid Coast, and 4-5ft+ surf on the South Coast (again, the W/SW direction capping size compared to a SW or S/SW swell). 

Local windswell may add a little more size into the mix along the Mid Coast, so there’s a chance for some small metro beachies on Friday if local winds hold above 25kts for most of the day. I’ll have more on that in Wednesday’s update.

This weekend (Oct 26 - 27)

Friday’s late frontal passage will dominate Saturday’s surf conditions with gusty SW winds easing, and a combo of swells producing 5-6ft+ surf at Victor and 3ft+ surf along the Mid Coast. Winds should ease more quickly on the Mid so conditions should improve during the day, but it’ll likely remain bumpy. 

Smaller surf is expected on Sunday with light variable winds and gradually improving waves along both coasts. There should still be some fun small waves on the Mid around 2ft+; Victor will be bigger but average with lumpy 3-5ft surf. 

Next week (Oct 28 onwards)

A very long period groundswell is expected to push into the coast on Monday, generated by an intense low pushing east from Madagascar longitudes over the coming days. The enormous travel distance will create very inconsistent waves, but we’ll see large periods (20+ seconds) at the CdC buoy and there’s a reasonable chance for a few small waves along the Mid Coast Monday and Tuesday with light winds. 

Otherwise, there are no other major swell sources expected to provide new swell through the first half of next week as a blocking pattern takes up residence across our swell window. 

Looking further ahead and another series of fronts are lurking at the tail end of the model runs and are suggesting we’ll see an upswing through the second half of the week, but that’s still some time away. I’ll have more details on Wednesday.