Western Australian Forecast by Craig Brokensha (issued Wednesday September 11th)

Best Days: This morning, tomorrow morning in the South West, Friday morning, Saturday, Sunday

Features of the Forecast (tl;dr)

• Small tomorrow AM, with a mod-large SW groundswell building strongly later, peaking early Fri AM
• Moderate E-E/NE winds ahead of sea breezes tomorrow
• Moderate E/SE tending fresher S-S/SE winds Fri
• Slow easing trend on the weekend 
• Fresh to strong E/SE-E tending variable winds Sat
• Fresh to strong E tending variable winds Sun
• Smaller Mon with strong E/NE-NE tending weaker N winds
• Large S/SW groundswell late week

Recap

Conditions were a little wind affected and not great across all locations yesterday morning along with a low point in swell energy.

Into the afternoon some new mid-period SW swell started to show and this has cleaned up nicely into this morning while easing with surf to 5ft in the South West, 2ft Mandurah and 1-2ft across Perth.

Fun in the South West this morning

This week and next (Sep 12 - 20)

Tomorrow will again be clean but smaller across the state with Perth and Mandurah bottoming out and being the tiniest it’s been in a while.

Margs should still offer 4ft sets on the magnets, but into the afternoon a new pulse of SW groundswell is due, with a peak expected Friday morning.

The source has been a strong low forming just west of the Heard Island region with a great fetch of prefrontal gale to severe-gale W/NW-NW winds being followed by similar strength W/SW winds to our south-west today.

The swell should build strongly tomorrow afternoon but with sea breezes, reaching 6ft+ in the South West, peaking Friday morning to 6ft to occasionally 8ft before easing during the day. Mandurah should see 2ft sets Friday morning with 1-2ft sets in Perth.

The easing trend will be slowed into the weekend thanks to trailing fetches of weaker W/SW winds, with Saturday easing from 4-5ft in the South West, with a reinforcing mid-period swell Sunday to 3-5ft. Perth will become tiny, with slow 1-2ft sets across the magnets in Mandurah.

Coming back to the winds and moderate E/SE winds are due Friday morning ahead of S-S/SE sea breezes, with Saturday seeing fresh to strong E/SE-E winds, tending more variable into the afternoon.

Sunday looks good again as well with fresh to strong E tending variable winds ahead of possible late sea breezes.

Next week looks generally small with fading swell energy into Monday, further Tuesday.

Strong E/NE-NE tending weaker N winds will favour selected breaks in the South West Monday with N/NE tending N/NW winds on Tuesday.

Later in the week, a strengthening of the westerly storm track to our south-west and south should generate some larger S/SW groundswell for late next week. Winds will take a southerly bias but we’ll review this Friday.