Western Australia Surf Forecast by Craig Brokensha (issued Monday 21st August)

Best Days: Perth and Mandurah tomorrow morning, protected spots around Margs when winds swing. Margs Wednesday, Thursday and Friday AM, all spots Saturday

Recap

Finally clean conditions across the South West Saturday but the swell was back to a smaller 4ft, while Sunday was a touch smaller again with less than ideal S'ly winds.

Perth and Mandurah were back to the 1-2ft range and best Saturday morning.

Today onshores were back in across the South West with a small 3-4ft of swell, while further to the north, Perth and Mandurah saw lumpy and fun 1-2ft surf with variable breezes. A new large SW groundswell is due to arrive later in the day across the South West, but more on this below.

This week and weekend (Aug 22 - 27)

A vigorous polar storm generated a great fetch of severe-gale W'ly winds west of and in the Heard Island region late last week. This has produced a large and inconsistent SW groundswell that's due to arrive later today and peak tomorrow morning around 6-8ft across the South West and 2ft+ further north.

Conditions will be best north of Margs with a variable tending offshore breeze, while W'ly tending S/SE breezes are due in the South West, favouring protected spots once winds swing.

Wednesday looks much cleaner with E/SE offshores across all locations but the swell will be smaller and easing from the 4-5ft range, helped by some mid-period reinforcing SW energy. This swell is being produced by a weak polar front currently north-east of Heard Island.

Thursday will be slightly smaller but clean again with an offshore breeze through the morning.

Into the end of the week and weekend we'll see some fun new swell filling in across the state, generated by a vigorous polar frontal progression forming late in our swell window.

An initial pre-frontal fetch of gale to severe-gale W/NW winds will generate a fun SW groundswell for Friday, but a broader and better aligned post-frontal fetch of W/SW winds should generate a larger S/SW groundswell for Saturday.

Margs should see good 3-5ft waves from the initial pulse Friday, maybe 1-1.5ft at magnets around Mandurah and Perth, with the S/SW groundswell coming in at 6ft+ across the South West Saturday and 1-2ft to the north.

Conditions are looking great with all day offshores, continuing Sunday as the swell eases, but beyond this there's nothing too major on the cards. More on this Wednesday.