Western Australian Surf Forecast by Steve Shearer (issued Fri July 19th)

Features of the Forecast (tl;dr)

• Period of onshores and mid period large storm surf sets in from Fri, over the weekend and extends into Mon
• Easing onshore winds later Mon into Tues
• S/SW-S winds develop Tues into Wed
• Mid-sized S/SW groundswell Wed next week
• More sizey SW swells later next week with onshore winds expected
• Typical winter pattern favours areas north of Shark Bay

Recap

Plenty of onshore wind since the last recap with plenty more to come. Yesterday saw easing 6ft+ surf in the SW, smaller 2-3ft in Mandurah and 2ft in Perth under an onshore S/SW-SW tending W’ly flow. Similar winds today with bigger, stormier surf in the 8-10ft range in the SW corner, 3ft in Mandurah, 2-3ft in Perth. Lots more stormy, winter surf ahead.

Stormy mess today, more to come

This weekend and next week (Jul 19 - 26)

No great change to the weekend outlook. A slow moving complex low gyre is well to the south of WA with constant conveyor belt fetches reinforcing already active sea states and generating large swells for WA. A northwards sitting high is producing W’ly onshore ridging with the massive gyre. Pretty standard active winter pattern. 

We’ll expect large stormy surf with subtle ups and downs over the weekend, with the low points not under 8ft and the high points up in the 10-12ft range, especially on Sun. Winds will be mod/fresh W’ly, even W/NW’ly through Sun. Mandurah and Perth will see 3ft+ and 2-3ft of surf respectively during this period.

Similar size and wind conditions for Mon as the very stormy period continues.

By Tues we should see an easing in size and winds shifting back to the S/SW-S as a front clips the state and a new high pressure systemt ridges in from the Indian Ocean. Plenty of size still on Tues with the fetch associated with the front boosting swells again Wed into the 8ft range.

The coastal trough we mentioned on Wed as a potential source of offshores winds on Wed now looks to move inland instead so winds will remain from the SW-S on Wed, with waves at more sheltered spots available. 

Further ahead and a mid-latitude storm develops NW of Heard Island before merging with a more polar low and deepening, with 30ft+ seas generated. There’s still some model divergence around this storm but there’s medium confidence we’ll see a strong SW groundswell generated arriving in WA over next weekend.

Fronts are still expected to be active later next week, suggesting more onshore winds. 

We may see a break in that flow later next weekend.

We’ll see how this looks when we come back Mon.

Certainly an active period ahead with pumping surf for the NW and Indo.

Check back Mon and have a great (windy!) weekend!