Western Australia Surf Forecast by Craig Brokensha (issued Wednesday 20th September)

Best Days: No good days until Monday

Recap

Easing surf from the 5-6ft range with onshore winds around Margs, but Perth and Mandurah were really fun with variable breezes and good sized sets.

Today onshore winds were blowing across all locations along with some new building W/SW swell from a mid-latitude low that was sitting west-southwest of us earlier this week.

This week and weekend (Sep 21 – 24)

The South West has already reached the forecast 6-8ft from our new W/SW swell and we should see Perth and Mandurah kicking to 2-3ft.

This swell should ease back slowly into tomorrow from a more SW direction, but another vigorous mid-latitude system approaching from the west will start to affect the coast, bringing strengthening NW tending W/NW winds.

This is expected to generate building levels of stormy W/NW swell through tomorrow afternoon, increasing further as strong W'ly winds batter the coast into Friday.

Size wise, the Perth metro beaches and Mandurah look to build to 3ft tomorrow afternoon with 8ft+ waves due across the South West, increasing further to 4-5ft around Perth and Mandurah Friday afternoon with stormy 10ft+ waves across the South West. Strong W'ly winds will create poor conditions Friday, tending SW very late in the day, holding Saturday morning before tending back to the W through the afternoon.

This will be along with easing levels of W'ly swell, smaller into Sunday as winds remain onshore from the W/NW.

Now as touched on last update, a polar front projecting up from our south-west during the weekend is expected to develop into an intense mid-latitude low off our coast on Sunday, generating an impressive fetch of gale to severe-gale S/SE winds aimed towards western Indonesia.

This won't generate any swell for us, but as it moves east across us Monday and Tuesday we'll see winds swing fresh to strong out of the S/SE.

There'll be no decent size left across the state once the W'ly swell fades Monday morning with small background SW swells due. We'll confirm this Friday though.