South-east Queensland and Northern NSW by Steve Shearer (issued Wed July 10th)

Features of the Forecast (tl;dr)

• Fun sized E’ly swells Thurs with SW-S winds
• E’ly swells build Fri  under “trough-block” scenario with light offshore winds expected
• E’ly swells peak over the weekend with mostly offshore winds
• New S swell filling in Sun, favouring NENSW for size
• Easing E’ly swells next week overlapped by S swells from Mon
• Last pulse of E swell likely later Mon into Tues
• Stronger S swells likely Wed/Thurs, depending on position of low in Tasman
• More sizey S swell likely next weekend

Recap

Fun sized E’ly swells were in the 2-3ft range yesterday with some S groundswell in the mix in NENSW. Conditions were generally clean- still a bit of lump and bump around- under light winds. Clean conditions again today under light/variable winds with more 3ft surf from the E and some tasty waves around.

Nice, clean beachie options on the Sunshine Coast

This week (July 10-12)

A trough is currently clearing the coast, expected to anchor a broad E’ly fetch generated by a monster high straddling New Zealand. This anchored trough fetch, or trough block pattern is favourable for swell production for almost the entire Eastern Seaboard and will come with mostly offshore winds until the weekend brings a more S’ly biased flow to temperate NSW. We’ll see remnants of a small low at the terminus of the trough get captured over the weekend and generate S swells from the return flow of a regenerated low. Those swells are still looking a bit tricky to call as the new low ducks back in close to or behind Tasmania. We’ll sketch it out now and revisit details Fri.

In the short run and the current signal of E/NE swell hangs in the 3ft range with offshore W-SW winds early before a S’ly flow develops as a circulation forms in the trough line. This S’ly should stay light/mod in NENSW, a notch stronger in SEQLD. 

Similar size Fri morning. Winds will shift Fri as the circulation in the trough line moves south. We should see offshore W’ly winds, before winds shift SW in the a’noon. We will see a muscling up in size Fri mid-morning, as a prelude to a stronger increase over the weekend as windspeeds intensify into the circulation in the trough line. Size should push up into the 3-4 occ. 5ft range by lunch-time. 

This weekend (July 13-14)

We get a size upgrade over the weekend as a result of gales feeding into the circulation Fri. That would suggest a stronger, longer period E’ly swell with 5-6ft sets, possibly bigger at E facing magnets on the MNC. Pumping in other words. Straight offshore W’ly winds tending SW in the a’noon. Sat looks the goods.

We’ll see a mix of easing E and new S swell Sun from the return flow off the low (see below). We’ll see the E’ly swell come off the boil, with size to 4-5ft easing during the day and new S swell building to 4ft during the day in NENSW, smaller 2-3ft in SEQLD. Early W-SW winds should tend mod SW-S during the day. 

Next week (July 15 onwards)

Bit of a tricky outlook for next week. Looks like the trough block fetch re-energises close to the North Island late in the weekend into Mon (see below). That should give us one last pulse of E’ly swell filling in on the declining swell from that direction. We should see that pulse later Mon into Tues, back up into the 3-5ft range under W-SW tending SW-S winds.

Mon looks to stabilise in the 3-4ft range with E and S swells with winds shifting offshore as the low formed over the weekend drifts SW back towards Tasmania. 

Depending on the position of the low early next week we’ll be up for a stronger pulse of S swell generated by gales around the western flank of the low. That should see surf rebuild from the S Wed into the 4-5ft range. Expect revision to these estimates on Fri once we get a clearer picture of how that low will behave as it meanders around in the lower Tasman.

Offshore winds through most of next week should offer a wide range of good/great conditions across the region.

Broadly speaking surf should slowly come down from that peak later next week. 

We may see a strong new low/frontal progression linked to a cold outbreak push into the Tasman late next week (see below). Under this scenario we’d expect more strong S swell later next weekend. Plenty of action ahead so check in Friday for the latest updates.

Seeya then.