Sydney Hunter Illawarra Surf Forecast by Ben Matson (issued Fri Dec 22)

Features of the Forecast (tl;dr)

• Easing SE and S swells on Sat with building E/NE swells, light winds and clean conditions
• Easing surf Sun with early light winds, tricky conditions later as a trough approaches (freshening NE most likely)
• Difficult forecast next week; likely to be some peaky beachies around Mon/Tues though

Recap

Building S/SE swells reached a peak late Thursday between 4ft and 6ft (depending on exposure and coastal alignment) though fresh southerly winds have limited options. Brief window of W/SW winds occurred at most spots this morning before the southerly kicked back into gear. Size is now slowly easing across the region. A new E/NE swell is expected to show later today. 

This weekend (23 - 24)

No major change to the weekend outlook, though Sunday’s winds are looking a little fruity.

A lingering southerly flow is possible at a few spots early Saturday, but the small low embedded within the Tasman trough is moving south and weakening, so the most likely scenario is light variable winds in all areas, all day.

Surf wise, we’ll see steadily easing surf from the S and SE (sourced from two different fetches around the low), with size abating from 3-4ft to 2-3ft as the day progresses. 

As this occurs, we’ll also see a building E/NE swell reach a peak into the afternoon. This swell has been a little smaller and slower to build across the North Coast than expected (south from Yamba), so I am going to revise my expectations down to a peak in the 2-3ft range by the afternoon (smaller earlier). Either way the S/SE swell combo will be most dominant through the morning. 

Sunday will see a further easing of the S and SE swells (stray 2-3ft sets early, 1-2ft by lunchtime and into the afternoon) along with an easing of E/NE swell from whatever peak we see late Saturday. 

Sunday’s now looking at freshening NE winds as an inland trough approaches from the west. Model guidance is a little mixed on how this will evolve, GFS has a period of NE winds tending variable across the Hunter/Sydney region but concurrently a SE flow across the Illawarra as a small low forms in the trough line; ECMWF has a slightly less pronounced version, developing later. It's one of those days where anything could happen, and with declining swell prospects it's not worth spending too much focus on.

Either way, if you plan on surfing Sunday make it early for the most size and best conditions. Saturday is a better pick all round.

Next week (Dec 25 onwards)

No change to next week’s synoptic outlook for a complex coastal trough pattern. 

In fact it’s making the surf forecast quite tricky as the models aren’t in much agreeance as to where the strength of the trough will lie, and thus where the swell generating winds will be positioned, and aimed. 

What they are in agreement on is the broadscale nature of this pattern - stretching from eastern SA through Vic and across NSW into the western Tasman Sea - though present indications are that aside from a brief period of easterlies winds aimed into the South Coast from late Sunday through Monday (then retreating further south into Tuesday), our swell window will see patchy activity.

Which doesn’t mean no surf - it just means low confidence, unreliable swell sources (see below). And flukey winds too.

I’m always reluctant to sit on the fence for any kind of forecast but best efforts right now are suggesting peaky beachies in and around the 2ft+ mark north from the Illawarra on Monday and Tuesday, but becoming bigger as you head south from the Illawarra (and also at risk of onshore winds here too).

The swell charts look slow for the rest of the week, but I wouldn’t read too much into that right now as these complex troughs patterns have a habit of turning about face at the last minute. 

Elsewhere, and the long term trends suggest a long wave pattern may develop next weekend (leading to a renewal of southerly groundswells into the following week).

Have a great weekend!