Western Australia Surf Forecast by Craig Brokensha (issued Monday 6th January)

Best Days: Tomorrow morning, Friday morning, Saturday morning in the South West

Recap

Great conditions and fun waves across the South West swell magnets Saturday, back to 2-3ft yesterday and clean again. Mandurah was a clean 2ft on Saturday, tiny Sunday with Perth 1-2ft and peaky Saturday morning.

Today the swell had reached a low point but we've got some new swell building across the coast but with onshore winds.

This week and weekend (Jan 7 - 12)

The building mid-period swell today will be followed by larger levels of W/SW groundswell tomorrow, generated by the remnants of Tropical Cyclone Calvinia which drifted east-southeast through our swell window from Madagascar late last week and on the weekend.

There's no change to the expected size tomorrow, but winds are now looking more favourable.

The South West should see sets to 6ft+, 2ft to occasionally 3ft in Mandurah and 2ft in Perth, easing through the day and smaller Wednesday.

A morning SE tending E/SE breeze in the South West will create clean conditions ahead of sea breezes (SE around Mandurah), while Wednesday looks still average with S/SW tending SW winds in the South West, fresh S tending S/SW winds to the north kicking up an afternoon increase in windswell.

Wednesday's onshore winds will be generated by a currently strong, but weakening mid-latitude low approaching from the west-southwest, generating a large swell for Thursday.

This low is currently north-east of Heard Island, generating a good fetch of W/SW gales. It'll project towards us while maintaining strength tomorrow, weakening Wednesday.

A large mid-period W/SW swell should build from the low on Thursday, reaching 6ft to occasionally 8ft across the South West into the afternoon, 2-3ft in Mandurah and Perth. Winds will be average and S/SW across the South West, S/SE further north Thursday morning ahead of sea breezes, while Friday looks great with E/SE offshores in the South West, SE to the north as the swell eases.

Easing sets from 6ft are expected in the South West, 2ft+ Mandurah and Perth, smaller Saturday with morning E/NE-NE winds.

Longer term there's plenty more mid-period swell on the cards for next week, but more on this Wednesday.