Sydney Hunter Illawarra Forecast by Steve Shearer (issued Wed April 10th)

Features of the Forecast (tl;dr)

• Raw S swell Wed with fresh SW-S winds
• Swell tending S/SE-SE through Thurs, easing slowly Fri and into Sat as low drifts towards NZ
• Strong S’ly winds Thurs, easing Fri
• S’ly groundswell pulses likely from Thurs PM into the weekend and next week- see notes for details
• Light winds over the weekend
• Small and Clean Mon-Tues next week

Recap

Clean and fun E/NE swell yesterday morning was in the 2-3ft range with good quality options around before winds really freshened from the SW-S as a low started to wind up east off Sydney. A late increase in raggedy S swell didn’t offer much size and despite near gales off the coast this morning, the low has been too close to the coast and we’ve started the day with an underwhelming 4-6ft of S swell, although we will see size build through the day. Protected locations are small, with some minor leftover E/NE swell offering up the occ. 2ft set. 

S swells still building under fresh SW-S winds

This week (Apr10-12)

There’s currently a robust Tasman low, still intensifying, moving slowly SE off the Central NSW coast down into the Tasman Sea towards New Zealand. Gales to severe gales wrapping the SW flank of the low will supply plenty of impoving S’ly- SE'ly swell through the rest of the week. Under this sharp trough in the jet stream, as Craig pointed out, strong polar fronts are being steered NE below the Tasman, with long period S swells wrapping into the East Coast. NE infeed into the low and a retreating E’ly fetch in the South Pacific will both add small E swell sources into the mix. 

Strong SW/S winds in the short run should start to ease after lunch as the low moves away from the coast. Plenty of S swell in the water, with size in excess of 6ft at S exposed breaks, smaller in more sheltered spots. Through they we’ll see longer period S swell fill in which will mostly be masked by the more proximate source but offering long lines in the 3-5ft range. 

Pressure gradients should have eased enough Fri for a morning offshore breeze, SW at most places, more W/SW north of the Harbour. We should see the primary swell source from the Tasman low shift more S/SE-SE and hold size in the 4-5ft range with occ. bigger sets. Long period S groundswell under that will supply sets to 3-5ft at S facing beaches. An a’noon shift in winds to the E/NE will tend more NE south of Sydney, potentially opening up direct S facing reefs.

This weekend (Apr 13-14)

Still looking good for the weekend with light winds both days. Light offshore breezes both mornings should extend well into the mid/late morning before tending to light SE/NE breezes in the a’noon, under a light, troughy environment. 

A mix of SE and long period S swells on Sat should provide plenty of energy in the 3-4ft range with occ. bigger sets.

More of the same Sun, with the primary SE swell slowly easing, reinforced by another pulse of S swell to 4ft in the a’noon. These S’ly groundswell pulses will be up and down and overlapping so there will be soft and loud periods through the day. 

Next week (Apr 15 onwards)

Still looking like light winds through Mon next week under a weak, troughy pattern with a weak S’ly change Tues.

Sunday’s pulse looks to ease into Mon, with clean 3ft surf on offer at S exposed breaks. 

More mid/long period S swell pulses continue into next week, likely persisting through the end of the week. These are now looking smaller- in the 2-3ft range at S facing beaches.

We’re also looking at some longer range E swell making landfall from a distant E’ly fetch that will supply some inconsistent 2ft sets from Wed.

Winds look to be light S-SE from Tues-Thurs as a broad area of low pressure sits in the lower Tasman and a high drifts NE. 

A frontal intrusion later next week should bring a small/moderate S swell into next weekend.

We’ll see how this all looks on Fri. Seeya then.