Western Australian Surf Forecast by Steve Shearer (issued Fri May 20th)

Features of the Forecast (tl;dr)

• SW swell building Fri PM, peaking Sat with good winds, easing Sun with NE winds tending NNE to NW in he PM
• Large W swell Mon arriving with cold front bringing strong onshores
• Large swells easing Tues, with reinforcing pulses and onshore winds 
• Multiple mid-sized pulses Wed-Fri with dicey winds, check Mon for latest
• Long range WSW swell on radar to end June

Recap 

Small surf has been on offer since Wed. Thursday saw small 3-4ft WSW swell in the SW with tiny surf elsewhere and mod NW winds. Today has seen more small surf, 2-3ft in the SW, tiny elsewhere with NE winds. Through the a’noon, new swell is beginning to build with some 3-4ft sets on offer in the SW, smaller 1-2ft in Mandurah and tiny in Perth.

This weekend and next week (May 20 - 27)

No great change to the weekend f/cast. An approaching low sees winds tend NE through Sat and with moderate WSW swell offer here should be some great fun waves around. Expect size in the 4-5ft range in the SW, grading smaller 2-3ft in Mandurah and 2ft in Perth. Winds should be good for most of the day Sat.

Winds remain NE through Sun morning but we’ll be on the backside of the swell so expect longer waits for sets and size easing from 4ft back to 3-4ft in the SW, smaller 2ft elsewhere. Through the day expect winds to clock around NNE and eventually end up N to NW as a front approaches. Long period WSW forerunners will show through the a’noon but it will be unlikely they will arrive before winds swing NW.

Into next week and we’re in for a couple of wild and wooly days as the front smashes into the state Mon, bringing wild weather and large storm surf mixed with long period groundswell. That should see victory at sea conditions Mon with strong NW to W winds and surf in the 10-12ft range, surfable only at protected spots facing away from the swell direction. 

Conditions start to moderate a notch through Tues with size settling down into the 6ft range before another pulse of swell generated by a front slingshotting up the parent low later Sun/Mon rebuilds surf into the 6-8ft range, grading smaller 3ft in Mandurah and 2-3ft in Perth. W winds tend WSW to SW opening up a few more protected spots.

Another front with a parent low passes to the south of the state Tues-Thurs with an intensification of the low at the edge of the WA swell window.

Earlier incarnations of the system near Heard Island Sun/Mon (see below) produce mid-sized SW swell pulses with surf in the 4-6ft range in the SW Wed, grading smaller 2-3ft in Mandurah, 2ft in Perth. Pulses of swell from this system as it tracks towards WA, maintain surf in the 4-5ft range Thurs, easing a notch Fri.

Front hitting the SW with another fetch riding up behind it producing plenty of mid-sized SW swell next week

Winds look iffy most of the week with a S’ly flow Wed and a slight possibility of a weak ridge bringing offshore winds Thurs. Check back Mon and we’ll finesse the wind f/cast.

Into next weekend and the flare-up of the low as it passed under the state Thurs will see SW-SSW swell for the weekend, with Sat seeing surf in the 3ft range and 3-4ft surf for Sun. Surf will be much smaller in Mandurah and Perth due to shadowing from the Cape to Cape region.

Longer term and a complex low pressure gyre around Africa which is active Tues-Thurs next week will see multiple pulses of long range WSW swell heading across the Indian Ocean, likely making landfall early week beginning 30/6. 

Well have a fresh update on that scenario on Mon.

Seeya then and have a great weekend!