South-east Queensland and Northern NSW Forecast by Steve Shearer (issued Wed July 30th)

Features of the Forecast (tl;dr)

• 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
• Small early Sat with a steep increase in size across MNC/North Coast in the a’noon, smaller in SEQLD
• Offshore winds north of the low, strong SE south of the low
• Large swells developing Sun, biggest in NENSW with W winds tending to S’ly gales
• Large swells through next week, tending to large SE-E/SE groundswells with light winds

Recap

Not much to report with small, background E swells hovering in the 1-2ft range and some extra S swell showing to 2ft at S swell magnets in NENSW. Winds were generally light offshore yesterday tending to NW breezes (light NE o/night in places) with light offshore today tending light SW/S through the a’noon.

Small, clean lines of swell across the North Coast

This week (Jul 28-Aug 1)

A precursor low and trough are moving offshore today from the NSW Mid North/North Coast bringing mod/fresh S’lies south of the low. The trough lingers and then deepens rapidly in response to an upper cold pool on Sat. A deep, complex low pressure system (see Beast from the East) then forms in the Tasman and slowly migrates towards the North Island with large E’ly swell pulses generated over a prolonged period. This event will be occupying most of our f/cast attention through the rest of this week and next. 

In the short run we’ll see the S’ly flow ramp up tomorrow with a period of W/SW-SW breezes before S’lies freshen through the day- stronger on the MNC and weaker north of Tweed-Byron. We should see a response in short range S-S/SE swell through tomorrow, with size whipping up from 2-3ft into the 4ft range through the day in NENSW, smaller 2ft at SEQLD S facing beaches where small E’ly swell’s will remain dominant with inconsistent 2ft sets. Not much size or quality to it so keep expectations pegged low.

This initial spike in short range S-S/SE swell holds into Fri morning before backing off as the fetch responsible quickly dissipates and drifts eastwards. Still some 3-4ft surf around in NENSW at S exposed breaks, smaller into SEQLD. Seasonal land breezes should have a W’ly component early before tending SE but we should see winds swing W’ly in northern regions through the a’noon as a low starts to wind up off the Far North Coast. The low axis looks to be initially around the QLD border but we’ll refine that on Fri. Expect temperamental winds around the low through later Fri. Nothing is expected to really develop until Sat so windspeeds should stay light.

This weekend (Aug 2-3)

We’ll have one last look at this Fri but models are now all broadly in agreement over the upcoming low pressure event. 

By first light Sat morning we should see a developing low pressure centre off the NSW North Coast (likely on the Coffs Coast) with a high pressure centre over Tasmania.

Pressure gradients between these two systems tighten quickly through Sat with strong SE-E winds developing on the southern flank of the low and likely extending from the MNC down through the Hunter and into Sydney-Illawarra with a N-S gradient in windspeeds. Gales could develop about the MNC Sat. North of the low- most of the North Coast and SEQLD we should see W’ly winds. It’s likely we will see small surf most of the day in most of the region. The MNC to Coffs coast is more likely to see a rapid rise in SE-E swell through the a’noon, possibly extending up to more northern areas while areas north of Ballina-Byron are more likely to stay small (2-3ft) through the day. We’ll give this a last tweak on Fri.

O/night Sat into Sun the low deepens further and a broad fetch of E’ly gales to potentially severe gales will be aimed up at the NSW Coast. Proximity= size so expect a wild and woolly ocean to develop Sun with large SE’ly-E’ly swells likely to develop across the MNC to North Coast in the 10ft+ range (potentially bigger if the low deepens more explosively than f/cast). We may see a slingshot of the low centre to the NW, parallel to the NSW North Coast bringing S’ly gales through Sun. Surf will develop later in SEQLD with an undersized start likely before size really ramps up through the a’noon, although remaining smaller (6-8ft across the Gold Coast at open beaches, 4-6ft on the Points, smaller on the Sunshine Coast) than NENSW through this initial stage. Early is likely to be the best conditions with lighter W-SW winds before S’ly gales develop through the day.

Next week (Aug 4 onwards)

E’ly gales in a broad fetch remain into the new week with a massive high new New Zealand (1042hPa) acting as supporting cradle for the Tasman low which will be drifting eastwards to a slot north of the North Island. That will lead to elevated surf from the SE-E for most of next week with just a very slow, gradual tapering off as the fetch slowly weakens while remaining basically semi-stationary. Embedded pulses are likely during this slow taper off as areas of stronger winds in the fetch retrograde westwards.

We’ll pencil in size in the 8-10ft range Mon, with size remaining in the 6-8ft range Tues and in excess of 6ft Wed. 

Incidentally there will be some very long period S swell in the mix Sun/Mon from an intense polar low which flares up as it tracks through Tasman Sea longitudes- it probably will  not be noticeable during the full frontal E’ly swell barrage during this time but sets to 3-4ft should be in the water Sun, easing Mon.

OK, local winds. Looking good. They should be rapidly improving into the new week as high pressure moves over the continent. 

The S’ly flow might still be a little bit sticky into Mon but only light and improving through the day to light SE breezes. 

Certainly by Tues we should be in a light wind flow with morning offshores and light a’noon S/SE-SE breezes.

That pattern should extend through Wed and into Thurs with freshening N-NW winds a possibility then as a new front/low approaches from the W.

Easing swells Thurs and Fri but we’re not likely to see surf drop below 4ft until next weekend.

Further ahead we may see another low form in the Tasman over next weekend (9-10/8) - although only EC is interested at this stage.

Lot’s to focus on short term so we’ll keep eyes on that and report back Fri for a last looks before the weekend.

Seeya then.