South-east Queensland and Northern NSW Forecast by Steve Shearer (issued Mon July 28th)

Features of the Forecast (tl;dr)

• Small E’ly swells persist through Tues/Wed
• Small S swell later Tues into Wed (NENSW only)
• W’ly winds tending NW Tues, NW winds tending W’ly on Wed
• Winds freshen from the W/SW-SW tending S’ly Thurs with an increase in S swell favouring NENSW
• Similar but a notch smaller Fri
• Dynamic weekend ahead with intense low expected to form off NENSW/SEQLD coast
• Likely a large increase in size later Sat into Sun
• Offshore winds north of the low, strong SE south of the low
• Large swells into next week, tending to large SE-E/SE groundswells mid week with light winds
• Dynamic f/cast so expect revisions, check back Wed for the latest

Recap

The weekend came in close to script with Sat seeing onshore NE windswell offering mostly 2ft sets with the occ. bigger wave on the MNC. Small and clean on Sun with tiny leftover NE swell and inconsistent E’ly swells offering 2ft sets under bluebird skies. Today is seeing similar surf, with fresh offshore winds and inconsistent E’ly swells offering up an occ. 2ft set (mostly 1-1.5ft).

Small and inconsistent but nice and groomed on the beachies when they come

This week (Jul 28-Aug 1)

High pressure is up over sub-tropical NSW, drifting into the Tasman and a massive low which swept up over the SE of the continent is now moving SE of Tasmania without showing too much in the way of swell generating winds for the east coast. A retreating broad trade fetch feeding into a trough is still supplying small E’ly swells. As mentioned on Fri- we’ve got an unstable atmosphere expected over the Tasman this week with an inland surface low pressure modelled to move into the Tasman mid week before moving away swiftly to the east. Over the weekend there’s now growing agreement on a coastal low (possibly some variant of an ECL) to form off the NENSW or SEQLD coast and intensify as it moves into the Tasman, with potential for severe weather and sizey swells. There’ll be plenty of revisions as we move closer to this event so we’ll outline it today and tighten the focus as we move through the week.

In the short run troughs related to the current decaying low SE of Tasmania generate bands of W-SW winds across NSW and adjacent to  Tasmania. That will see a mostly W’ly flow across the sub-tropical region tomorrow, with potential for winds to shift NW to N in the a’noon as another trough arm related to the next inland low approaches the region. Not much surf around- just a continuation of small, background E swell to 1-2ft and some minor S swell to similar sizes. 

Not much surf into Wed. A small boost in E’ly energy looks likely - adding inconsistent 2ft sets to the mix. Some minor S swell in the mix from the fetch adjacent to Tasmania will add surf of similar size at S swell magnets in NENSW, not affecting SEQLD. Winds look tricky as the inland low and trough exit the coast between Sydney and the Hunter coast. We should see NW winds, possibly tending N/NW at time swinging more W/NW to W in the a’noon as the low exits the coast. 

The low winds up o/night Wed into Thurs with a broad flank of strong S/SE-SE breezes developing on the southern flank. That will generate a modest short period S- S/SE swell through Thurs under mod/fresh W’ly tending SW- S’ly winds across NENSW with lighter breezes in SEQLD and a’noon seabreezes. We should see size build up in the 3-4ft range at S facing breaks in NENSW bigger 4-5ft at the true S swell magnets, smaller 2ft in SEQLD where inconsistent E swells provide most of the swell energy.

A strong high pushing through the Bight holds a ridge along the coast Fri so S’ly winds continue at mod paces. We should see a period of W/SW breezes inshore early,  although open beaches are likely to remain wind affected. Size comes down a notch as the low pressure system moves away quickly with size in the 3-4ft range likely at S exposed breaks in NENSW, smaller 2 occ. 3ft in SEQLD where a slightly improved swell direction will help swells get in north of the border.

This weekend (Aug 2-3)

There’s broad model agreement now for a low to form off the sub-tropical coast and merge with a Coral Sea low pressure centre, deepening explosively through Sat and into Sun. Exactly where the low forms and moves will have a large material impact on surf size and especially local winds- so keep that in mind particularly if you are planning to chase the swell. 

Basically the ECMWF resolution is for the low to form off the North Coast closer to Coffs with offshore winds across most of the North Coast and SEQLD through Sat, strong onshore E/SE-SE winds across the MNC and extending southwards through the Hunter and Sydney-Illawarra, although with decreasing speed as you head south. 

GFS has the low forming off the SEQLD coast with onshore winds across the Gold Coast and North Coast, extending down to the Hunter and Sydney at much lighter strength and tending more S’ly. 

Both models suggest a rapid deepening into Sun with gales to severe E’ly gales developing in a broad fetch across the Southern flank of the low. 

Either way we are looking at a significant weather and surf event- likely focussing on the MNC for maximum size at this stage over the weekend.

Ballpark for size is likely to be in the 4-5ft range Sat, bigger 6-8ft Sun (possibly in the 8-10ft range across some of the MNC) with smaller surf north of the border- but those figures are likely to be revised as we get more clarity on how the situation will evolve.

We’ll dial in details further on Wed.

Next week (Aug 4 onwards)

As the deep low moves eastwards towards the North Island  it aims up gales to severe gales back towards the east coast and we’re on track to receive some powerful swell from the SE-E/SE through next week. 

Sizey into Mon in the 6-8ft range in NENSW, smaller 5-6ft in SEQLD but we’ll be waiting for the stronger longer period swell to fill in later Tues and into Wed.

That looks to offer some real size and quality up again in the 6 occ. 8ft range with bigger sets possible.

High pressure should be drifting over NSW during this time suggesting light offshores and light a’noon seabreezes. 

Still a lot of water to go under the bridge before we get there - so expect revisions when we come back Wed. 

Seeya then.