South Australian Surf Forecast by Craig Brokensha (issued Friday August 18th)

Best Days: Keen surfers Mid Coast tomorrow but mostly the South Coast, Mid Coast Sunday morning, down South all day, South Coast Monday and Wednesday, Mid Coast early Monday and Wednesday, both coasts Thursday (Mid Coast morning)

Features of the Forecast (tl;dr)

• Mod-large mix of SW swells Sat, easing and smaller Sun
• Gusty W/NW-W winds Sat (lighter at times on the Mid), W/NW Sun (possibly variable early on the Mid)
• Moderate sized mid-period W/SW swell Mon with fresh N/NW winds (N/NE early Mid Coast)
• Mod-large mid-period W/SW swell building Tue ahead of a larger SW groundswell Wed
• Strong SW winds Tue, tending W/SW through the day
• Light to mod NW winds Wed
• Easing surf Thu with local offshore winds, tending N/NW through the day

Recap

A good pulse of W/SW groundswell provided 2ft waves on the Mid Coast yesterday cleanest early before becoming wind affected and choppy through the day. The South Coast was also a fun size and to 3-4ft across the Middleton stretch, cleanest in the morning and a little windy after lunch.

Today a strong frontal system is moving through whipping up 2-3ft of choppy swell for the Mid with 4ft+ waves down South.

This weekend and next (Aug 19 – 25)

Today's frontal is linked to the weakening low bringing tomorrow's pulse of stronger SW swell energy, with a fetch of persistent gales generated through our swell window throughout this week.

We should see the South Coast coming in at a stronger 4-6ft across the Middleton stretch with 2ft to occasionally 3ft sets on the Mid Coast under gusty W/NW winds. There will be periods of more moderate W'ly winds across the Mid Coast through the day but all in all it'll be bumpy and for the keen.

W/NW winds look to persist Sunday morning as the swell eases back from the 4ft range on the South Coast, 2ft across the Mid and with likely variable winds in the gulf through the early-mid morning.

Later in the day Sunday but more so Monday, some new mid-period W/SW swell is due to fill in, generated by pre-frontal W/NW gales sliding in from the south-east Indian Ocean, today, under Western Australia this evening.

This will then be followed by a secondary burst of tighter, similar strength winds, producing a reinforcing pulse of SW groundswell for Monday afternoon.

The Mid Coast should persist 1-2ft through Monday with 3-4ft waves across Middleton along with favourable N/NW winds across the South Coast, N/NE early on the Mid.

Looking at Tuesday and more so Wednesday, we've got some larger mid-period and groundswell on the way thanks to the following Southern Ocean frontal progression moving in behind the pre-frontal W/NW gales.

A broad, slow moving fetch of W/SW gales should generate some moderate-large W/SW mid-period swell for Tuesday, building through the day, while a stronger, tighter low forming on the backside of the progression looks to generate severe-gale W'ly winds on top of an active sea state. This will produce a larger SW groundswell that looks to peak Wednesday.

Size wise, the Mid Coast on Tuesday should build to 3ft through the afternoon with Middleton building to 4-5ft, with Wednesday persisting around 3ft on the favourable parts of the tide across the Mid Coast, 6ft+ down South.

Winds currently look poor Tuesday as a trough clips us, bringing a strong SW change, shifting W/SW through the day. Wednesday should see winds revert back to the NW, favouring the South Coast but only light so the Mid Coast should be workable. As the swells ease on Thursday, light local offshore winds are likely, but we'll confirm this Monday. Have a great weekend!