A period of small surf ahead with N'ly winds while we watch the tropics come to life

Steve Shearer picture
Steve Shearer (freeride76)

Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Mon 27th Dec)

Forecast Summary (tl;dr)

  • Increasing short range SE swell likely Mon PM, peaking Tues, slowly easing Wed
  • Longer period S swell  holding Tues morning before easing
  • Small surf Wed-Fri with winds easing, then a N'ly pattern
  • Small, NE windswell on the cards for New Years weekend
  • Tropical cyclone likely off QLD coast New Years weekend, uncertain outlook for Central NSW, E/NE swell likely to build Tues. Check back for revisions.
  • New S swell possible Tues/Wed next week


The Xmas weekend contained a few small rideable windows of waves, mostly on Xmas day itself which featured a rideable blend of small swell trains in the 1-2ft range, clean early before NE winds kicked in. A long range S/SE groundswell underperformed with only a few stray 2ft sets on offer through the a’noon. Boxing Day saw a stiff S’ly change working it’s up the coast with only a brief window of clean conditions, longer on the Hunter. Surf remained in the 2ft range, slightly stronger 2-3ft on the Hunter. This morning has seen an increase in S swell, mostly shorter period windswell with some longer period S swell building in underneath it. Size is a building 3ft, bigger 4ft on the Hunter, with cleanest conditions at protected spots away from strong S’ly winds, which are seeing much smaller surf. 

Building surf from the S was enough to produce some rideable surf in the Bays

This week (Dec 27-31)

As we discussed on Fri, Boxing Day has brought a pattern change after a troughy, doldrums period before Christmas. A strong 1033hPa high is located well to the south of the Bight, with a ridge now surging up the East Coast. In the tropics the Monsoon trough is now active, with good odds of cylogenesis before the New Year. Troughs also lie across the North of the country, extending southwards along the eastern interior and in the Coral Sea down to the Northern Tasman. It’s a hot, moist mess at the moment with a highly fluid synoptic environment. Lets try and make some sense of it.

In the short run the wave climate will be dominated by swell trains from the S, mostly short period SSE swell generated by proximate SSE/SE winds from the high pressure surge. That should peak through Tues with surf in the 3-4 ft range at exposed breaks, bigger 4-5ft on the Hunter, with an easing trend during the day as the fetch migrates northwards. Local winds will be the issue with a mod/fresh SE flow expected. Lighter S’ly inshore early. Some leftover longer period S swell should help more protected locations as it refracts into these spots.

Pressure gradients should ease quite quickly Wed through the f/cast region as a small subsidiary high splits off the main cell and drifts NE to be stationed off the South Coast during Wed. That will see easing SE winds, tending light E’ly through the day. The regime of short period SE will be dwindling with 2ft leftovers. Some mid period S swell from a passing front well to the south of Tasmania Mon is expected to supply some 2-3ft surf at S facing beaches during the day, bigger 3ft+ on the Hunter. 

The rest of the working week/end of the Year will see small surf through Central/Southern NSW. Leftover S swell Thurs should see a few leftover 2ft waves early at S facing beaches, before fading out through the day. Light NW winds early will see the best surface conditions of the week. Those winds will tend NE in the a’noon and freshen.

New Years Eve looks to be a classic Summers Day in the f/cast region, with mod N’ly winds, tending NE and freshening during the day. There won’t be much surf to speak of. Another small pulse of S swell working up the coast from a poorly aligned fetch will see a few 1-2ft waves at S facing beaches through the a’noon, with the more reliable S swell magnets in the 2ft range. NE windswell should bump up into the 1-2ft range through the a’noon. Bigger on the South Coast. If you’ve got the appropriate small wave board and mindset you’ll find a rideable wave to end the year.

This weekend (Jan 1 - 2)

All the action will be up North to start the year. We’ll likely be looking at a tropical cyclone or low in the Coral Sea New Years Day. This won’t have much bearing on the surf in temperate NSW until next week so the weekend maintains small waves.

With a slow moving high slap bang in the middle of the Tasman Sea we’re expecting N to NE winds both Sat and Sun. That should see some useful NE windswell start to develop as the fetch takes shape. We should see some rideable 2ft NE windswell both days, with bigger surf on the South Coast, where the fetch is stronger.

Of course the caveat is if any cyclone or tropical low drifts south faster than F/cast. At present models still hold any storm close to the QLD coast through next weekend, or at least in tropical latitudes, which limits swell production for southern NSW. We’ll have all week to monitor that and update as needed before the weekend.

Next week (Jan3 onwards)

Everything next week hinges on the tropics and the movement of our expected tropical storm(s). Major models are roughly split between two main scenarios.

EC model suggests a coast hugging system, tracking south to be off the Fraser Coast on the weekend, before washing out and dissipating over the inland early next week 3/1. This scenario would generate a large swell for QLD, with size rolling off steeply south of the QLD border. E’ly winds through the Northern Tasman would see an E/NE swell of modest dimensions build through Tues, likely peaking Wed/Thurs in the 3ft range with accompanying onshore E to E/NE winds.

GFS suggests not just a low tracking across from Cape York Peninsula, but a series of lows forming along the monsoon trough line, extending out to New Caledonia (see below).

The sees a long fetch of SE/ESE winds develop through the Coral Sea and Northern Tasman, with a chance of the low near New Caledonia retrograding back towards the East Coast in a SW direction. There’s also a chance of a retrograding low forming near the North Island. Under this scenario the f/cast region would see a slow building E/NE swell through later Tues into Wed. 

That scenario also sees a front push a S’ly change up the coast bringing S’ly winds and an increase in S swell through Tues and Wed. 

EC has traditionally been the more reliable model but GFS has an excellent reputation for tropical predictions.

Best bet is to pencil in surf time next week and check back in on Wed. We will monitor the upcoming systems closely and give a full update then, as well as in the comments if things change radically before then.


Craig's picture
Craig's picture
Craig Wednesday, 29 Dec 2021 at 11:57am

EC ensemble forecasts are fairly solid with the tropical cyclone dipping south into the Tasman Sea while staying offshore.

A good outcome for us with solid E/NE swell and S winds.