Western Australian Surf Forecast by Steve Shearer (issued Wed July 17th)

Features of the Forecast (tl;dr)

• Easing (still sizey) W/SW-SW swell Thurs with more onshore winds
• 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
• We may see SE winds develop  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

Solid W/SW swell filled in yesterday to 6-8ft across the SW, with smaller 2ft surf in Mandurah and Perth under fresh NE tending N/NE winds which made surfing conditions very challenging. Winds have deteriorated further today tending N to NW before a front sees winds swing SW later in the day. Plenty of size with surf to 6-8ft in the SW, 2-3ft in Mandurah and 2ft in Perth. We’ve got a period of onshore winds aheads. 

Plenty of size yesterday but strong NE-N/NE winds made for challenging conditions

This week and next week (Jul 17 - 26)

No great change to the short term outlook. Lots of size and lots of onshore wind as the W’ly storm track rides high and blows right across the SW of the state. Strong to gale force SW tending W winds Thurs with strong W tending SW winds Fri will confine surfing to a few winter spots north of the Cape. 

There’ll be plenty of size on tap. A long fetch of SW gales is aimed up and moving towards WA (see below) as part of a complex gyre well south off the state. Rotating fetches around the edge of the gyre will hold large pulses of SW swell right through the end of the week into and over the weekend. To find offshore winds for this swell you’ll have to head north of Shark Bay.

We’ll see as temporary easing in size through the short run with size to 5-6ft in the SW, 2-3ft in Mandurah, 2ft in Perth.

Expect size Fri to build into the 6-10ft range, 3ft in Mandurah, 2-3ft in Perth.

Swells build from there with overlapping pulses from the rotating reinforcing fetches operating on an already active sea state. Likely up into the 8-10ft range Fri and 10-12ft over the weekend. 

Again, straight onshore winds the whole time and with plenty of strength, so if you can’t head north, then you’ll have to poke around sheltered winter spots and surf the swell wrap into sheltered bays.

We should see a slight easing in size Mon but still solid 8ft+ surf under heavy onshore winds. 3ft in Mandurah, 2-3ft in Perth.

Winds next week now look a bit tricky to call. 

ECMWF suggests another front hitting later Tues or Wed with another round of stiff W tending SW onshores and a renewal of sizey SW swell Wed.

GFS is still suggesting a trough off low pressure to form off the mid-west coast (see below) with an offshore flow (SE-E/SE) forming on Wed as new swell fills in. 

We’ll update that wind forecast Fri.

Both models suggest a return to onshores with a high riding mid latitude low striking the SW of the state late next week, bringing a sizey swell with it.

Let’s see how these competing model visions shake out on Fri.

In the meantime, lots of typical winter onshore winds to get through.

Seeya Fri