Western Australia Surf Forecast by Ben Matson (issued Monday 21st October)

Best Days: Entire period: quite a few large swells but tricky winds at times. Most size expected Thurs but with onshore winds. Best swell/conditions combo likely Friday. Another strong long period swell this weekend too. 

Recap: Our flukey S’ly swells eased steadily across the Margs coast on Saturday, though conditions were clean with offshore winds. Much smaller panned out into Sunday and it’s been tiny for most of today though the early forerunners of new long period swell seem to be pushing through the coast this afternoon. Perth and Mandurah coasts have been very small for the last few days. 

New lines showing at Margs this morning

This week (Oct 22 - 25)

The publish time of these Forecaster Notes will be erratic this week, as Craig’s on annual leave. To receive an email when they go live, please edit your user settings here: www.swellnet.com/user

So, we’re just playing the waiting game at the moment. WA’s buoy network isn’t ideal to monitor swell conditions (because the way the data is presented is different to convention) so the surfcams are probably a more useful tool to see where things are at. 

We’ve also had a slight downgrade in surface conditions on Wednesday and Thursday as a powerful low well to the south just clips the south-west corner of the WA coast. This will maintain moderate to fresh onshores these days, though the low itself will contribute a strong secondary groundswell. Winds will be lighter north from Bunbury but still likely to be onshore for the most part. Tuesday should be generally light and variable across all coasts.

Prior to this - i.e. from now onwards - we’re looking at building long range groundswells from an unusually stationary sequence of lows in the central southern Indian Ocean last week. Wave heights should trend upwards all day Tuesday, probably peaking into Wednesday morning with 10-12ft sets at exposed spots across the Margs region, but the swell direction is favourable for the metro coasts so we should see 3-4ft surf in Perth and 4-5ft surf in Mandurah (smaller through Tuesday as it builds). Early Wednesday morning should see a window of lighter winds north of Bunbury.

The primary groundswell will persist into Thursday but as mentioned above we’ll see a strong secondary swell from the aforementioned approaching low (see below), which should briefly peak wave heights into the 12-15ft range across the Margs region, and maintain a similar size range across metro beaches as per Wednesday. However, model guidance is suggesting a little more strength in the onshore breeze, which may thwart options here (though it’ll be SW across the Margs region so protected bays and points will have good options).

We’ll then see rapidly easing surf across all coasts on Friday with light variable winds as a high pressure system moves in from the west. Lingering onshores are likely across the Margs region in the morning but it’ll abate steadily through the day. The metro beaches should have fun waves in and around the 3ft mark (slightly bigger in Mandurah, slightly smaller in Perth).

This weekend (Oct 26 - 27)

The wave models show an incredible fan of long period groundswell pushing across the Indian Ocean later this week. It’s being sourced from an intense low developing well south of Madagascar at the moment (see above), and the leading edge (20+ seconds) will arrive early Saturday, with surf size building into the afternoon and peaking Sunday. The low is nicely aimed towards our region, but quite north in latitude so the swell direction looks like it’ll be W/SW.

The enormous travel distance will shave off a lot of size but we can expect solid 10-12ft+ sets by Sunday afternoon (way bigger at the offshore bombies thanks to the large swell periods), and at this stage a developing heat trough along the coast is likely to strengthen S/SE winds across the region during the day. We can again expect a decent round of swell across metro beaches too, so it’ll be well worth booking in a weekend session (Sunday the pick).

Next week (Oct 28 onwards)

Plenty of strong Southern Ocean storm activity for the longer term too, with a series of fronts through the swell window expected to maintain elevated wave heights throughout next week. But let’s concentrate on the upcoming events first!

See you Wednesday.