South Australian Surf Forecast by Ben Matson (issued Friday 8th September)

Features of the Forecast (tl;dr)

• Today's large storm swell easing steadily through Saturday with winds tending W'ly and abating
• Light winds Sunday with fun waves at Victor and small leftovers on the Mid
• Good winds down south all of next week
• Nice S/SW swell building down south Mon, easing Tues
• Small clean surf down south Wed/Thurs
• Not much on the Mid next week until Thurs when we'll see a small new swell
• Good W'ly swell options for the Mid around next weekend and beyond

Recap

Small swells on both coasts with freshening westerly winds made for generally average surf on Thursday. We've seen a very large southerly storm swell build today, offering some of the largest waves in a long time at Victor Harbor, along with a bog standard Mid Coast stormy. It's hard to put a size on things down south, but exposed spots look easily 8-10ft (how's the lines of whitewater at the Dump!). 

The Dump showing lines and lines of whitewater breaking way outside the usual take off zone this morning

This weekend (Sep 9 - 10)

The main features for the weekend are a rapidly easing swell and a steadily abating wind that'll tend westerly on Saturday before becoming light and variable on Sunday. 

The mid-latitude low responsible for today's south swell is moving out of our swell window so expect size to ease pretty quickly, maybe some leftover 5-6ft sets early Saturday, down to 3-5ft by the afternoon and then leveling out around 3ft+ on Sunday. 

Initially, the southerly swell component will maintain a broader coverage of size across the region than what we uually see under predominant SW swells, which means good potential for protected spots. However there will be plenty of leftover wobble from today's winds. 

The Mid Coast should see small lumpy leftovers on Saturday, easing from a lacklustre 2ft or so, smaller into Sunday with a minor reinforcing swell not expected to contribute much new energy. However there will be waves for the grommets. 

Next week (Sep 11 onwards)

Light variable winds tending northerly are expected throughout most of next week, which should create great conditions across all regions. 

As for surf, we'll see a temporary low point at dawn on Monday, but over the following hours a new S/SW swell is expected to fill in, towards a broad peak in size from late afternoon through Tuesday. 

This swell will have been generated by an interesting slow moving polar low currently skirting the ice shelf, which is expected to stall, broaden and intensify right on the eastern periphery of our swell window over the weekend (see below).

Nice fetch sitting below Tasmania on Sunday, that'll generate a decent S/SW swell for Mon/Tues

Once again, the extra southerly component in the swell direction should be a benefit to South Coast locations that are partially sheltered (under SW swells). At this stage we should see wave heights build into the 4-5ft range at exposed coasts by Monday afternoon, easing slowly through Tuesday, bottoming out Thursday with nice small options across the open beaches under the offshore wind regime.

Small residual swells will pad out the Mid Coast for the first half of next week with no major surf on the radar at this stage. The storm track is currently not well lined up for this swell window. 

Beyond this, the long range surf outlook is quite promising, with an initially quiet Southern Indian Ocean expected to fire up mid-next week, developing a northern storm track through the Bight, which suggests a series of inbound westerly swells that'll be really good for the Mid Coast.

The first new swell is due around Thursday, but much bigger pulses are due the following weekend (worth putting into the diary) and the expected synoptic pattern trailing behind looks favourable at this (very) early stage. 

More on this in Monday's update. Have a great weekend!