South swell aplenty, average winds

Craig Brokensha picture
Craig Brokensha (Craig)

South East Queensland and Northern New South Wales forecast by Craig Brokensha (issued Monday 11th July)

Best Days: Every morning over the coming period in semi-protected spots


Saturday started off slow across most regions with a small E'ly swell across the Gold Coast and building S'ly groundswell on the North Coast with morning W/SW winds.

The swell really kicked into the afternoon though but conditions were poor with onshore winds across most locations.

Early Sunday morning was the pick as the S'ly groundswell backed off under early light NW winds, but these quickly freshened from the N/NE, limiting the best waves to protected northern corners.

Today the swell has continued to back off but conditions were much cleaner ahead of a S'ly change which has since moved through. This should kick up a short-range S'ly swell across the North Coast this afternoon but with no decent quality.

This week and weekend (Aug 12 - 17)

Today's S'ly change and short-range S'ly swell is associated with a strong polar front that fired up under Tasmania Saturday evening, projecting a fetch of weakening severe-gale S/SW winds up past Tassies East Coast through our southern swell window.

This has produced a moderate to large S'ly groundswell which fill in later tomorrow afternoon and peak to 5-6ft across exposed south facing locations on the North Coast (larger on the Mid North Coast) while the Gold Coast isn't expected to see any real size above 2ft at open beaches. Before the S'ly groundswell fills in though there'll be moderate levels of short-range S'ly swell from today's change.

Winds will be a problem and fresh from the S/SW tending S/SE tomorrow (possibly SW in certain pockets of the coast), but Wednesday looks better as the S'ly swell slowly eases under SW winds across most locations (even W/SW in some spots).

Thursday will continue to provide plenty of size from the tail of the front generating Tuesday/Wednesday's swell, but winds will deteriorate again, becoming fresh from the S/SW to S/SE. This will limit the best conditions to protected spots, which will be much smaller.

A reinforcing but inconsistent S'ly groundswell pulse is due on Friday produced by another cold front pushing up through the Tasman Sea from below Tassie, but the direction and strength won't be as good as the current system. As a result only inconsistent 3-4ft sets are expected across exposed south facing breaks on the North Coast, with 1-2ft sets at open beaches on the Gold Coast. Winds will continue from the S/SW to SE, limiting surfing options.

Into the weekend, one final pulse of S'ly groundswell is due from a final polar front firing up within our swell window to the south-west of New Zealand. This front will be very strong but only form late within our window, resulting in smaller side-band S'ly swell energy spreading out from a large swell impacting New Zealand.

South facing beaches should pick up inconsistent 3ft sets Saturday before backing off through Sunday. Winds look as if they'll be variable Saturday morning but into Sunday conditions will deteriorate with a strengthening NE wind associated with a deepening inland surface trough (discussed in more detail below).

Next Monday onwards (Aug 18 onwards)

The longer term outlook is quite interesting as we're expected to see an inland surface trough deepening in central Australia, move east and drift offshore early next week some-time.

What this should result in as a strengthening northerly pressure gradient off the East Coast as the trough squeezes against a strong high sitting in the Tasman Sea, kicking up moderate to possibly large levels of short-range NE tending E/NE swell.

If this does eventuate we're expected to see poor winds during the initial building stages of the swell, but once the trough moves offshore, winds should swing accordingly offshore, creating excellent waves. When and if this happens will have to be looked at in more detail Wednesday.