South Australian Surf Forecast by Craig Brokensha (issued Monday June 12th)

Best Days: Today South Coast, stormy options tomorrow on the Mid, South Coast Wednesday and Thursday morning, South Coast Saturday and Sunday

Features of the Forecast (tl;dr)

• Temp low point in swell tomorrow AM down South with strong W/NW tending W/SW winds
• Large mix of W/SW swells filling in on the Mid through the day, later down South, easing slowly Wed with fresh W/NW tending strong NW winds
• Easing surf Thu with fresh NW winds
• Building windswell Fri with gusty N/NW winds
• Mod-large W/SW groundswell for Sat with gusty N/NW winds, stronger NW Sun with a slight drop in swell
• Smaller Mon with strong W/SW winds

Recap

Excellent surf all weekend on the South Coast and around the state for that matter with a mix of moderate sized mid-period swell for Saturday morning being superseded by a large, strong pulse of SW groundswell.

Conditions were excellent for the South Coast with the surf reaching 6-8ft, while on the Mid Coast there were wind affected 2-3ft waves for the keen. Yesterday the swell started to ease but with great conditions on offer across the South Coast again, similar today with easing 3ft sets across Middleton. The Mid Coast is wind affected and a tiny 1-1.5ft.

Sets still on offer this morning

This weekend and next week (Jun 13 - 18)

Make the most of today before the swell drops further tomorrow morning and winds strengthen out of the W/NW, shifting W/SW as a strong mid-latitude low pushes in from the west.

We're looking at fading 2ft sets across Middleton ahead of some new W/SW swell from the mid-latitude low, discussed below.

The Mid Coast will see a large mix of building windswell, mid-period energy and groundswell, generated by the strong mid-latitude low, which fired up to the south-west of Western Australia on the weekend.

This low generated a great fetch of strong to gale-force W/SW winds while projecting east, and this will kick up a large 3-4ft of swell for the Mid Coast through tomorrow. The South Coast will see a bit less size owing to the west direction, building to 4ft across Middleton/Goolwa later in the day.

Both regions will ease in size on Wednesday from a similar range to that seen later tomorrow and winds will be best for the South Coast, fresh from the W/NW, strengthening from the NW through the day.

Smaller surf is expected into Thursday under fresh NW winds, but only easing from 2ft off Middleton.

As touched on in last week's update, we've got some new W'ly swell due from the Friday but more so the weekend and it will be quite a prolonged event thanks to a slow moving, southern ocean gyre setting up under the country.

This gyre will essentially be a large, broad area of low pressure with multiple low pressure centres spinning around inside it, producing multiple fetches of gales through our western swell window while moving slowly east.

This will produce multiple pulses of moderate to large W/SW groundswell that will peak on the weekend.

The first system will develop east of the Heard Island region this afternoon, projecting a fetch of gale to severe-gale W/SW winds east, generating an inconsistent W/SW groundswell for Saturday morning.

A better, larger secondary pulse of groundswell will override this though, generated by a secondary, closer in proximity fetch of gale to severe-gale W'ly winds under Western Australia on Thursday. A third, slightly weaker and less favourably angled fetch will then soften the easing trend on Sunday/Monday.

The Mid Coast looks to come in at 3ft+ on Saturday, easing slightly to 3ft on Sunday, with Middleton offering strong 4-5ft sets, possibly more 6ft towards Goolwa, then easing back from 4-5ft on Sunday.

Winds will shift to the N/NW and be gusty on Saturday ahead of the gyre moving slowly east, stronger NW on Sunday with the backside of the gyre moving through Monday, bringing a W/SW change.

We're expected to see moderate levels of weaker, mid-period energy through next week as weaker frontal activity continues, but check back Wednesday for more on this.