Western Australia Surf Forecast by Craig Brokensha (issued Friday 18th August)

Best Days: Swell magnets Margs tomorrow morning, Perth and Mandurah Tuesday morning, Margs Wednesday onwards

Recap

Large onshore surf continuing across the South West with a new SW groundswell while further north conditions were great with clean 3-5ft sets around Mandurah and 3ft+ waves up in Perth.

This morning the swell is back down to 2ft around Perth and 2-3ft in Mandurah with early favourable winds, while Margs remained onshore and poor.

This weekend and next week (Aug 19 - 25)

The surf will become smaller again tomorrow as winds finally swing offshore across the South West. A surface low sitting to our west will move east and across us overnight, with light E/SE offshores due before the low keeps moving east, bringing a S'ly change.

Sets are only due to be around the 4ft range across the South West, easing through the day, with tiny fading 1-1.5ft waves to the north.

S'ly winds will persist into Sunday, swinging more onshore during the day as the swell bottoms out.

Our new SW groundswell due into early next week is still on track, with a vigorous polar frontal progression firing up west of Heard Island yesterday, generating a broad fetch of severe-gale W'ly winds through our swell window. The storm will slowly weaken over the coming days, with the long-period SW groundswell due to build through Monday ahead of a peak Tuesday morning.

Winds will unfortunately be onshore Monday and from the W/NW across the South West, while Perth and Mandurah look clean but tiny in the morning.

The swell should build to 6ft+ later Monday and peak around 8ft Tuesday morning across the South West, with 2ft+ waves in Perth and Mandurah. Winds are a little suss for Margs again with a lingering W'ly after Monday, while Perth and Mandurah should see light morning offshores.

After this the swell will drop away with offshore winds kicking in around Margs Wednesday and easing 4-6ft sets.

Longer term there's only small to moderate sized swells due late week and into the weekend along with offshore winds, but more on this Monday. Have a great weekend!