Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed Dec1 )

Forecast Summary (tl;dr)

• Small, pulsey E swell suitable for a grovel Thurs/Fri, with flukey, light winds
• Small increase in junky S windswell Sat PM with S'ly winds
• Slightly more S swell Sun with S'ly winds tending E/SE, E'ly in the PM
• Small E'ly surf Mon-Wed next week with onshore winds
• Possible juicy E swell from Thurs next week as low retrogrades in from New Caledonia, stay tuned for updates

Recap

The downslope of the weekends SE swell punched above it’s weight through later Mon and into Tuesday with plenty of 3-4ft surf (bigger Mon PM) and a clean window Tues morning before NE winds kicked in. South facing beaches had good surf all day. Size has now dropped back into the 2ft range, with a slightly bigger 2-3ft signal at exposed coasts like the Hunter. Quality has reduced with a scrappy NE surface texture across most breaks. All in all, still fun for a grovel.

This week (Dec1-Dec3)

High pressure is now drifting over New Zealand with multiple trough areas through the Tasman Sea, interior, and extending along the East Coast from the tropics down to temperate NSW. This is creating a moist, variable, onshore flow  through the region with small surf. A small low is expected to form off the Mid North Coast in the trough line overnight bringing S’ly winds to the Northern part of the state whilst the region south from Seal Rocks  remains in the weak onshore flow. A stronger S’ly flow is created on Sat as a weak front pushes into the Tasman and trough reforms in the Central Tasman sea.

In the short run small E’ly and SE’ly energy pads out the working week. This is being generated by a broad, but narrow fetch of sub-20 knot tradewinds between the North Island and New Caledonia and another weak fetch of SE winds feeding into the Tasman trough. 

That will see surf in the 1-2ft range, with subtle ups and downs through Thurs/Fri and most of Saturday. Winds will be likewise flukey. Mostly variable through Thurs morning, tending E’ly to E/NE in the a’noon.

Expect a more  NE flow Fri, before winds tend NE/SE then variable. There’s no real strength in the synoptic flow so light land breezes or glass-offs are likely. 

You should be able to find a small grovel wave to get wet both days.

This weekend (Dec 4-5)

The weekend f/cast gets a downgrade in both size and quality compared to Mondays notes. The trough which was expected to form in a similar fashion to last weekend is now more diffuse and lacking strength which leaves the bulk of the swell generation to a cold front tracking past Tasmania and transiting the Tasman sea through Saturday. Models are still a bit divergent on the strength of the front, with GFS offering a more dove-ish assessment, and thus affecting most wave models. We’ll run with the more conservative assessment for now and hopefully be in a position to upgrade on Fri.

Saturday starts small and with a continuation of small, weak surf and light winds as a trough lingers somewhere between Sydney and the Hunter. These winds will tend S’ly and kick up through the day as the front passes through and high pressure quickly ridges up the coast. 

Some models are picking up an increase in S swell through the a’noon, but any increase will be short period junky windswell, so it’s probably best to keep very low expectations for Saturday.

Winds should moderate through Sun but with high pressure moving E of Tasmania a ridge along the NSW coast will see winds quickly clock around from S/SE to E/SE or E. An increase in S swell is expected to push wave heights up into the 2-3ft range at S facing beaches, slightly bigger 3ft on the Hunter but quality will be way down at the junky end of the spectrum. 

Scappy, onshore surf will be available Sun with not enough swell to realistically get into more sheltered corners.

Next week (Dec6) and beyond

With the failure of the trough to organise the high pressure flow into a swell generating fetch on the weekend we now start next week in a very different position to Mondays notes. 

An E to E/NE onshore flow is likely as high pressure near New Zealand maintains a ridge along the coast.

That provides a small signal of swell from the E, mostly short period and low quality, in the 2ft range, 2-3ft at magnets.

Winds clock around to the NE through Tues and Wed as the ridge breaks down and the western flank of the high creates N’ly winds down the NSW coast. Slight change to the weak signal of E to E/NE swell as it changes direction but not size or quality.

The second half of next week is subject to major uncertainty.

The crux of the uncertainty is an area of low pressure forming just south of New Caledonia later this weekend/Monday. GFS model feeding most wave models has the low quickly intensifying and retrograding in a S/SW-SW direction towards the East Coast. 

Under that scenario we are on track for a solid increase in E swell from Thursday next week, with size in the 4-6ft range and S’ly winds as a change pushes up the coast.

The low then degrades into a long trough, with E/NE winds aimed in a broad swathe towards Southern NSW.

Other major models like EC have much less bullish outlook with the low remaining weak and washing out SW of New Caledonia.

That would see a slight increase in E swell into the end of next week from that source.

A much more distant fetch located between 170-160W roughly SW of Tonga from Sat and extending E from there, is expected to supply some persistent small levels of long range E swell into next weekend, although this will be more noticeable from the Mid North Coast northwards. The long travel distance is expected to shave off most of the size so we’re only looking at inconsistent 2-3ft sets. 

With so much model uncertainty- a feature of the atmospheric instability through the SW Pacific caused by La Nina- lets pencil in E swell from mid next week and check back Fri to see how it’s shaping up as far as the details go.