Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Mon Jan 8th)

Features of the Forecast (tl;dr)

• Freshening NE winds Mon with workable NE windswell
• NE windswell eases into Tues at workable levels with a window of offshore winds before a morning S’ly change
• Small S swell trains later Tues into Wed (wind affected by S-SE winds)
• Small E/NE swells from mid week from top of high
• Workable E-E/NE swells this weekend from retrograding fetch in South Pacific
• Uncertain outlook next week, plenty of activity possible from trough and potential low off Tasmania- check back Wed for revisions

Recap

S/SE swell Sat morning held up a little better than expected, enough to supply some fun morning waves in the 2-3ft range with clean morning conditions. Sun was smaller as that swell source dried up, although fresh N/NE winds in the a’noon did begin to generate NE windswell up to 3ft by close of play. That NE windswell is with us this morning at a workable 3ft+ level ( a bit weak and tidally affected) with early light N’ly winds (NW-N/NW across most of the region) now tending to freshening N-NE winds with a bit more top end expected on the current NE windswell event.

Chunky NE windswell to kick off the working week

This week (Jan 8-12)

We’ve got a very unstable pattern as the MJO sweeps across Northern Australia and convective activity penetrates the country via a long trough and NW cloud band, linking up with a developing low off the North-East coast of Tasmania. Once the Tasmanian low clears the picture we’ll see monsoonal activity develop through the South Pacific/Coral Sea, likely with a broad area of low pressure squeezing pressure gradients along a long fetch between the North Island and near Island chains and retrograding back towards the East coast through the second half of this week (see below). East swells will favour the sub-tropics for size, but we’ll see swell trains from this source filter down into temperate NSW. Longer term is starting to look very active as well. Let’s look at the specifics.

In the short run and we’ll see a trough working it’s way north tomorrow, bringing a S’ly change due into Sydney around 8am (earlier on the Illawarra), with a window of offshore W-W/NW winds beforehand. If you can time that there’ll be some leftover NE windswell, down off todays peak, but with a few 2 occ. 3ft sets before it fades away through the day. A few small S swell trains from the compact fetch adjacent to Tasmania will supply some 2ft surf more prominent in the South Coast but with a S wind it’ll be hard to utilise.

Small S swells extend into Wed- only in the 2ft range with the odd bigger one at S facing magnets. High pressure slips into the Tasman and pressure gradients ease rapidly so light winds early with a S’ly bias, tending light E to E/NE in the a’noon. 

Another trough Thurs will bring a S-SE flow across the f/cast region with just a small, weak blend of background S and E/NE swells in the 1-2ft range.

Rounding off the working week is another small, grovel day with light onshore winds (possibly land breezes early) and weak SE swells. We may start to see some E/NE swell filter down from the retrograding E’ly fetch in the South Pacific. Models seem uninterested but we’d expect some 2ft sets to show up at open beaches through the a’noon under current modelling.

This weekend (Jan 13-14)

High pressure straddling and E of New Zealand will have set up a long, tradewind fetch in the South Pacific with the extremity of that fetch extending into the Northern Tasman. Winds remain fairly weak in the fetch but the extended nature of it (setting up a fully developed sea state) means we should have workable levels of E-E/NE swell this weekend. Nothing sizey, just in the 2 occ. 3ft range and with a light onshore flow. 

Light E’ly breezes, tending NE in the a’noon Sat and with good odds for a morning land breeze. Sunday may see winds shift more E to SE as a new high pressure ridge builds on, although we’ll see how the timing of that looks on Wed. In short, a few small, fun beachies will be on offer for the weekend.

Next week (Jan 15 onwards)

OK, lots of action on the charts next week but with lots of model divergence and poor run to run consistency we’ll be revising through the week.

The basic building blocks of a large high pressure belt under the continent and increasing tropical instability seem locked in. The curve ball is potential troughiness in the Tasman, which EC suggests will anchor a long SE-E/SE fetch through the Central/Northern Tasman next week, bringing plenty of swell from that direction under an onshore flow. 

GFS suggests a weaker trough with small/moderate amounts of E-E/SE swell through the middle of next week. Potentially a low may form in the Coral Sea near New Caledonia.

GFS suggests a deep trough may form a surface low east of Tasmania mid next week (see below), with a possible spike in S swell later next week ion the system deepens and forms S’ly gales in the Tasman.

Like I said, lots to keep an eye on as the tropics enters a more active phase and the Tasman bubbles up along with it.

For now, it’s another working week of small Sumer surf to grovel through.

Check back Wed for the latest.