Sydney Hunter Illawarra Forecast by Steve Shearer (issued Wed June 25th)

Features of the Forecast (tl;dr)

• S swells build through Thurs becoming sizey with early W-W/SW winds shifting SW-S through the day
• Solid S swell Fri AM with offshore winds, winds tending S-S/SE and easing
• Nice blend of S-S/SE swells Sat with light winds
• Small leftovers Sun from the S with small E/NE swell in the mix
• Long range E swell fills in Mon, persists Tues, easing Wed- long waits for sets!
• Long period S swell fills in Mon, holds Tues before easing
• Dynamic situation now on the radar next week with large surface low in Tasman possible
• Large S then SE swells possible Wed into Thurs/Fri
• Check back Fri for latest updates!

Recap

Just a small blend of E/NE and NE windswell yesterday that topped out in the 2ft range under freshening N tending NW winds. Close to dead flat today as W’lies freshen as a cold front sweeps across the state. We may still see a slight increase in refracted S swell late this a’noon but no great size is expected. 

Hard W'ly and almost dead flat- different story tomorrow

This week (June 25-27)

Associated with todays cold front is a low currently just to the SE of Tasmania and expected to track NE into the Tasman. Gale force W’ly winds are already being observed through Bass Strait with those winds expected to tend SW and propagate northwards through the day. That proximate fetch of SW-S/SW winds will be the main swell source in the short term. There’s also a much deeper fetch of SW gales connected to a polar low which is transiting the far southern reaches of the Tasman which will supply reinforcing S’ly groundswell. In the eastern swell window a massive high east of New Zealand and tropical depression in Tongan longitudes is reaching peak intensity and expected to send some meaningful E’ly groundswell towards the eastern seaboard, making landfall next week. More frontal activity through the lower Tasman keeps the southern swell window active medium term while the Tasman Sea now looks like showing enhanced storminess with major models in broad agreement over a large, complex surface low developing and good odds for a prolonged M/L swell event. 

In the short run the trend will be up through tomorrow, as the fetch of gales slingshots up the coast. Initial S swell to 3-4ft looks to build steadily through the morning with a more pronounced upwards trend to 6-8ft at S exposed breaks into the mid-late a’noon with some bigger sets at open S facing bommies. Fresh W-W/SW winds track SW fairly early then tend fresh S’ly before moderating a notch in the late a’noon. A fairly typical winter S swell event.

Winds start to moderate through Fri as the low moves away. Mod W/SW-SW breezes will clock mod/fresh S’y before laying down to light/mod paces in the a’noon. Still plenty of size with dominant mid-period S swell to 5-6ft (still some bigger sets at exposed S facing breaks), easing a notch through the day, offset by long period S swell trains filling in with 3-4ft sets.

This weekend (Jun 28-29)

The weekend is looking good as far as conditions go with light offshore winds Sat tending to light S-SE breezes, tending more W-W/NW Sun with light a’noon E-NE seabreezes. All day surfing should be on the cards both days. 

Surf-wise Sat looks active with plenty of both longer period S and mid period S/SE as the low tracks towards New Zealand (see below). That mix should offer up at least 3-4ft of quality surf with bigger sets likely at S swell magnets. 

By Sun size will be dropping down into the 2-3ft range, easing though the day with a minor signal of E/NE swell coming from a retreating trade fetch. 

Plenty of fun waves over the weekend. 

Next week (Jun 30 onwards)

Major upgrade now becoming increasingly likely for next week. 

To start, we’ll see light winds Mon tending S’ly as a weak, troughy feature between two high pressure cells moves off the NSW central coast. 

Small surf to start with E/NE swell from the South Pacific fetch filling in through the day and offering up quality but very inconsistent 3ft sets. 

From Tues July 1 the situation becomes extremely dynamic. We’ll sketch it out here, with the expectation of possible major revision as we get closer to the event.

The trough off the NSW Coast deepens Tues, with a large high in the Bight. That should see a surface low develop in the Tasman off the Hunter/MNC region. SW-S/SW winds would freshen as it does so. We may see some more local NE-E/NE swell from winds infeeding into the low, as well as long range E/NE groundswell in the 3ft range through Tues, with groundswell extending into Wed. 

A much more major local swell event would overshadow this mid-week if the low deepens as currently modelled with new S swell becoming large through the day (ballpark: 8ft, larger surf possible).

The low may occupy the central Tasman as it reaches peak intensity with SE gales aimed back at the NSW Coast and large S/SE-SE tending E/SE angled surf through Thurs/Fri. 

Way too far out to have any confidence in specifics but early model agreement is a good sign as far as the event itself is concerned so take it as a heads up and start pencilling in large surf next week now. 

We’ll come back Fri and see how it’s shaping up.

Seeya then!