Western Australia Surf Forecast by Craig Brokensha (issued Monday July 10th)

Best Days: Saturday all locations

Features of the Forecast (tl;dr)

• Large, long-period W/SW groundswell peaking tomorrow PM, easing Wed with strong NW winds (slim chance N/NE early Wed to the north)
• Large mid-period W/SW swell Thu with fresh W/SW winds, strong SW Fri with a reinforcing large SW swell
• Easing SW swell Sat with light E/NE winds in the north, E/NE-NE across Margs
• Low point in swell Sun with strengthening NW winds in the South West, NE early to the north
• Large to extra-large surf into next week with onshore winds

Recap

The South West was large and onshore Saturday with nowhere to really surf, choppier into yesterday as the swell remained sizey. Perth and Mandurah offered cleaner better surf, biggest on Saturday and to the 3ft range, a touch smaller yesterday and more peaky.

Today is onshore and poor again in the South West with less than ideal but workable winds (thanks to the northerly bias in the winds) to the north to 2-3ft as a reinforcing pulse of mid-period SW swell fills in.

This week and weekend (Jul 11 - 16)

The coming week will remain poor in the South West, with a strong mid-latitude frontal progression expected to bring a large, long-period W/SW groundswell for tomorrow, though with the associated onshore winds.

A great fetch of severe-gale W/NW winds moving through on the back of the mid-latitude frontal system that clipped us yesterday will generate a decent pulse of swell tomorrow but the size is down on last week's expectations.

It wasn't quite as strong as forecast and we should see the South West building to 12ft+ with 4ft sets in Mandurah and 3ft+ waves across Perth.

Winds will persist from the NW tomorrow, strong in nature with Mandurah and Perth not seeing any early favourable winds, with similar winds due into Wednesday. There's an outside chance of early N/NE winds in Perth/Mandurah Wednesday but don't count on it.

We'll fall under the backside of the frontal progression into Thursday, resulting in weaker W/SW winds and a fresh pulse of large, mid-period W/SW swell.

The source of this will be a fetch of pre-frontal gale-force W/NW winds, with a trailing fetch of weaker strong to gale-force SW winds due to slow the easing trend through Friday and Saturday.

Thursday's swell looks to be in the 10ft range across the South West, 3ft in Mandurah and 2-3ft across Perth but with that onshore breeze, persisting from the SW and strong Friday as the reinforcing SW swell fills in.

Come Saturday we'll finally see winds back off and go offshore across all locations and there should still be easing 6-8ft sets in the South West, 2ft+ Mandurah and 2ft across Perth.

Longer term the next round of frontal activity is due to fire up later this week around the Heard Island region, projecting towards us on the weekend and early next week. This looks to produce large to extra-large groundswell but with onshore winds. More on this Wednesday.