Western Australia Surf Forecast by Craig Brokensha (issued Monday 3rd March)
Best Days: Wednesday morning, Thursday morning, Sunday morning
What an excellent start to autumn! A strong and powerful SW groundswell filled in overnight Friday and peaked Saturday morning to a large 6-8ft+ in the South West, 2-3ft around Perth and 4-5ft+ up in Gero under morning offshores.
Wind started to shift more N'ly late morning before giving into weak sea breezes across most coasts ahead of a late S/SW change in the South West.
Sunday morning was still good north of Bunbury with morning offshores and an easing swell, while Margs saw less than favourable S'ly winds.
Today saw a renewal of SW swell energy but with less than perfect winds.
This week (Mar 3 - 7)
There's lots of swell on the cards for the coming period as a strong node of the Long Wave Trough intensifies to our south-west and then slowly moves across us over the coming weekend.
What the Long Wave Trough does is focus and intensify polar frontal activity up from the Southern Ocean, towards where ever it is amplified. With it sitting to our south-west we will see polar fronts steered up towards us, generating swell after swell after swell.
The next decent swell is due tomorrow afternoon, linked to the strong frontal system that's currently to our south-west. This swell is expected to peak overnight, but Wednesday morning should still offer 4-6ft waves in the South West, 2ft sets in Perth and 3-4ft+ waves up at Gero under offshore E/SE winds.
Thursday is still looking fun though with morning offshores, but a smaller swell.
Our next considerable groundswell is due on Friday and this will be a long-period and large swell, probably a touch smaller than the swell we saw Sunday.
This swell will be generated by another strong polar low firing up in the Heard Island region today (pictured right), aiming a similar fetch of 35-55kt+ W/SW winds towards us but for a shorter time-span and also at a further distance away from us compared to last weeks low.
This low will also break down to our south-southwest, leaving a long-range and less consistent SW groundswell to make its way towards us.
Still, we should see this swell building to 6ft to occasionally 8ft in the South West Friday afternoon, 2ft+ in Perth and 3-5ft around Gero. Winds will unfortunately be nowhere near as good and fresh to strong from the S/SW into the afternoon.
This weekend onwards (Mar 8 onwards)
Friday's swell will ease off into Saturday with average winds, while Sunday is looking great with a large SW groundswell expected to fill in with favourable winds.
Now this swell won't be bigger due to the wind speeds within the storm being stronger, but it will be because back to back frontal systems piggyback up over one another while pushing much closer towards us during the second half of this week, acting on the active sea state of the system before.
A peak in size to 6-8ft in the South West, 2ft to occasionally 3ft in Perth and 4-5ft+ around Gero on Sunday afternoon. Winds will be good as the swell builds and from the E/SE ahead of afternoon S/SW sea breezes.
Looking longer term and there's nothing as big as what's expected on Friday and Sunday due into next week, but we'll review this Wednesday.