Western Australia Surf Forecast by Craig Brokensha (issued Wednesday 16th August)

Best Days: Perth and Mandurah Thursday and Friday mornings, South West and Perth Saturday morning

Recap

Large stormy onshore waves continued across all locations yesterday, easing in size back into this morning but with no let up in the winds.

A strong front currently pushing into the South West of the state should produce an increase in new SW swell later today, peaking tomorrow, but this is discussed in more detail below.

This week and weekend (Aug 17 - 20)

A vigorous frontal system is currently clipping the south-west of the state, with a fetch of gale to severe-gale SW winds being generated in our swell window.

A large SW groundswellwill result and this swell should build later this afternoon ahead of a peak tomorrow morning in the 10-12ft range across the south West and 3-4ft in Perth and Mandurah.

Winds are still looking OK around Perth and Mandurah with a variable breeze likely to develop if not light E/NE, creating favourable conditions. Winds will also be weaker across the South West but still moderate from the W/NW, strengthen through the day as a small trough/low pushes up towards us.

This low is expected to move slowly east across the coast at some stage during Friday but the where the axis of the low sits depends of what winds the coast will receive.

It's real tricky to discern at the moment but the latest updates have the axis just sitting west of Margs, resulting in N/NW winds all day. If the low shifts east earlier we'll see winds tend variable and even light SE, but keep an eye on the local observations and weather radat. Perth should see N/NE breezes.

This will be along with easing levels of SW groundswell from 5-6ft across the South West and 2ft in Perth.

Saturday will see the low truly pushing east and with this we'll see SE tending stronger S/SE winds as the swell continues to fade (S/SE to S/SW winds Sunday).

Longer term a couple of good SW groundswells are due into early and mid-next week from strong back to back polar lows.

The first long-period swell for later Monday and Tuesday looks to be in the 8ft range and with variable winds during the mornings, while a secondary slightly smaller swell is due Thursday with SE offshores. More on this Friday.