Western Australian Forecast by Steve Shearer (issued Wed October 30th)

Features of the Forecast (tl;dr)

• Smaller SW swells Thu with E’ly winds
• Easing swells Fri and onshore winds
• Onshore winds for the weekend with a bump in size Sat, extending into Sun
• Onshorewinds Mon AM with small swells
• More size now expected next week with rolling moderate SW swells from Tues 
• Onshore flow expected Tues-Thurs, may tend more offshore Fri 

Recap

Size was roughly in the f/cast range yesterday (a little cool) with 4-5ft sets in the SW, smaller 2ft north of Bunbury with a window of offshore E/SE-SE winds before strong S’lies. Smaller today with inconsistent sets to 4ft (occ. 5ft ) between the Capes with waves around 2ft in Mandurah and less than 2ft in Perth. Winds were SE early before tending fresh S-S/SE-S/SW across most of the SW area.

Still some size on the reefs but a bit lumpy/bumpy

This week and next week (Oct 30 - Nov 8)

No change to the near term outlook. A high sliding in under the state and a coastal trough supplies E’ly ridging for tomorrow with offshore winds extending into the midday hours before a S-S/SE flow in the a’noon. Residual SW swells hold 3-4ft surf in the SW corner, smaller 1-2ft in the north, favouring exposed reefs for size.

Winds deteriorate on Fri as the trough moves inland and a front approaches. There should be a period of SE-NE winds around a weak troughy area before winds shift NW-SW through the day, likely by mid-morning. Leftover SW swells will see a low point in energy with 2-3ft surf on the exposed reefs, tiny/flat in Perth/Mandurah.

Into the weekend and we should see more energy than Monday’s notes expected. A cut-off low in advance of the front now looks more robust with a bigger trailing fetch in the swell window for longer. That should see mid period surf build Sat into the 4-5ft range across the SW corner, 2ft in Perth, 2-3ft in Mandurah. Winds will be a problem as the front drives an onshore flow across the region with SW-S/SW winds Sat, tending more W/SW on Sun. We may see a small window of SE or slack winds on Sun morning with glassy/lumpy conditions. 

Surf holds at similar sizes on Sun.

Next week looks little more active now as a fetch of SW gales over the weekend between 70-100E builds seas to 20ft. This should translate to a moderate SW pulse Tues in the 5-6ft range with a few bigger sets, smaller 2-3ft in the North. 

Expect another low point Mon with onshore winds.

Unfortunately for this Tues pulse the onshore flow still looks locked in as the long wave trough steers weakening fronts into the SW corner. We’ll see how ti looks on Fri but at this stage expect an onshore W’ly flow through Tues into Fri.

We’ll see more moderate SW-S/SW surf during this time frame as a conveyor belt of mod strength fronts get steered from 80E towards WA. 

Provisionally these look like supplying pulses in the 5-6ft range with bigger 8ft sets on exposed reefs. 

There is some model guidance we may see high pressure slip in under the state by Fri next week suggesting a return to better winds either later Fri or into the weekend.

We’ll update that outlook on Fri. 

Seeya then.