Sydney Hunter Illawarra Surf Forecast by Ben Matson (issued Fri 11th April)

Features of the Forecast (tl;dr)

• Small mix of E/NE and S swells this weekend (keep an eye out for sneaky S sets later Sat and Sun). Light winds and clean conditions
• Small E/NE swell for much of next week
• Building short range SE swell Tues/Wed buut likely wind affected
• Solid E/SE swell on target for Fri, easing Sat/Sun

Recap

Easing southerly swells on Tuesday maintained occasional 2ft waves at south facing beaches on Thursday, smaller elsewhere, holding into this morning. A flukey southerly groundswell has arrived this afternoon, showing occasional 3ft+ sets at south facing beaches (again, smaller elsewhere). Winds have been light both days with clean conditions in general.

New S'ly swell at Bondi this afternoon (via our surfcam)

This weekend (Apr 12-13)

It's a bit of a tricky weekend of waves, but the short version is there should be something fun and it’ll be clean on top.

Locally smooth conditions will be related to a high pressure system in the southern Tasman Sea, which extends a firm ridge along the Northern Tasman into the Coral Sea. 

This ridge will generate a building trade swell across northern regions, and we’ll see a small level of this filter into Southern NSW, building to 2ft throughout Saturday, and maybe 2-3ft on Sunday. It won’t be very powerful but the swell direction and low period should allow for some fun peaky beachies.

Also in the water on the weekend will be some long range southerly groundswell, glancing the outer fringes of the coast.

Easing swell from today will most likely provide inconsistent 2ft sets at south facing beaches on Saturday morning, however a series of new overlapping pulses are due from Saturday afternoon and throughout Sunday.

Given that today’s energy slightly overperformed, and the new energy originated from a similar storm passage through the same swell window, optimism is easy to grasp - but we need to be cautious for these upcoming swells as it’s still a super flukey swell window. Small changes in direction and period can have a dramatic change on surf prospects, even at supposedly reliable south swell magnets.

As such, it’s best to keep your expectations low, but keep an eye out for infrequent 2-3ft+ sets on Saturday afternoon and throughout Sunday at your favourite south swell magnet (also, the Hunter region often exaggerates these swells a touch more than the rest of Southern NSW).

Next week (Apr 14 onwards)

The anchored ridge through the northern Tasman Sea will supply useful trade swell all week throughout Southern NSW, albeit relatively small in size, around 2-3ft or so.

However, a secondary high pressure system is expected to develop south-east from Tasmania on Monday, and a small trough along its northern flank may squeeze the pressure gradient, creating a local short range SE swell source for later Tuesday and Wednesday, which may create 3-4ft sets.

Local winds look initially light on Monday morning but we’ll see a freshening trend as this ridge pushes up the coast. Monday afternoon is at risk of developing NE winds before southerlies kick in on Tuesday and Wednesday.

While this is going on, a complex series of low pressure troughs and easterly dips are expected to form near New Caledonia - atop the northern Tasman Sea ridge - before tracking south. 

The merging of troughs in the north, along with the a strengthening of the two ridges to the south, is expected to result in a deep low pressure system off the NW tip of New Zealand by Wednesday, with a broad belt of gale force easterly winds aimed towards New South Wales (see below).

The upshot of this is a powerful E/SE swell currently expected to impact the coast around Easter Friday, with wave heights likely up into the 5-6ft+ range, before surf size gradually eases over the weekend. 

The wave models have moved around a little in the last day or so - previous runs suggested surf size around 8ft, so I have tempered my outlook a little - and we can expect further revisions over the next few days, but this is certainly a swell event to keep an eye on.

See you Monday!