Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Mon 4th Sep)

Features of the Forecast (tl;dr)

• Easing SE swells Tues with offshore winds developing
• Small S swell spike Wed favouring Sydney northwards with light AM winds tending NE in the a’noon
• Small E/SE swell Thurs, with developing NE windswell in the a’noon
• Peak in NE windswell Fri AM with W’ly winds tending fresh SW in the a’noon
• Mod  S swell now on track for Sat, easing through Sun with mod/fresh SW-S winds, easing Sun
• Potential for large S-S/SE swell next week as low/front enters Tasman, potential for elevated wave heights most of next week

Recap

S-S/SE swell came in pretty hot over the weekend, at the top end or over f/cast expectations as a low pressure trough hovered in the Tasman. Sat saw 3-4ft surf across S exposed breaks, bigger 4-5ft on the Hunter with clean morning conditions under offshore winds before winds tended S’ly. Sunday eased a notch, offset by an improvement in swell direction with nice 3ft surf, a notch bigger on the Hunter and nice clean conditions extending well into the midday hours. Today has seen a general reduction in size from the S’ly quarter with 2-3ft surf, with some added E/NE swell in the mix to similar sizes. Early conditions were clean with a mod NE flow kicking in during the day. 

Glassy beachbreaks on a combo swell to start the week

This week (Sep 4-8)

The weekend’s low pressure system is still lingering near New Zealand, with the merger of the low with a tropical derived low not really happening. As a result the expected Cook Strait fetch isn’t as well aligned or juicy and will only be a minor swell source for the region. A pair of fronts from tomorrow race away quickly with a small spike of S swell expected. The following system expected over the weekend now looks much stronger and under current modelling is expected to be a significant source of sizey S swell, potentially with several large pulses. Lets look at the details.

In the short run we’ll see overnight N’lies tend NW-W fairly quickly through the morning as a pair of fronts approach then pass through Bass Strait, possibly at first light. That’ll offer clean conditions as SE-E/SE swell from the Tasman low eases. A few 2-3ft sets for the early then a downwards trend through the day with winds tending more W/SW-SW in the a’noon. 

Near gales out of Bass Strait and proximate to the South Coast Tues should see a small but distinct S swell spike for Wed. Nothing amazing but worth some 2-3ft sets at S facing beaches, favouring areas from Sydney northwards. Early W-SW winds lay down and tend light/variable before a high moving over NSW brings an a’noon N-NE flow. 

This flow is likely to freshen through Thurs as a complex trough/front and low complex approach from the W. That’s likely to see some workable NE windswell develop Thurs a’noon, likely peaking Fri morning in the 3ft+ range. Also in the water Thurs should be some small E/SE swell from the poorly aligned Cook Strait fetch (better aimed at Tasmania). Expect a few 2 occ. 3ft sets.

Fri morning looks good for NE windswell, as the approaching frontal system shunts winds to the W. These proximate fetches are fickle but do tend to over-produce, so we’ll pencil in 3ft surf for now, with good chances for an upgrade to 3-4ft. W’ly winds then tend to fresh W/SW-SW winds as the front/low start to push E of Tasmania, hopefully at a strength we haven’t see for a while. It’s unlikely we’ll see any swell increase Fri, but we’ll finesse that potential as we move through the week. 

This weekend (Sep 9-10)

Expect revisions as we move through the week but under current modelling the front/low/trough combo forms a a long angled fetch in the lower Tasman as the low moves away, then a proximate fetch of near gales to the NSW Coast as a long trough and low form in the Tasman. With near gales near the coast (likely fresh/strong SW inshore) we’ll see a rapid rise in S swell Sat, likely up into the 6ft+ range, bigger 8ft+ on the Hunter. Protected spots only under fresh S’ly winds.

Plenty of size still into Sun, although the initial peak is likely to come down in size as the proximate fetch moves away. That may see easing winds and potential light a’noon winds, with size in the 4-6ft range. Expect revisions through the week. 

Next week (Sep 11 onwards)

Another large blast of S swell likely early next week, as another front enters the Tasman, reinforcing the existing long trough/low and potentially forming a new low. Under EC modelling the reinforced low sits in the Tasman, offering up elevated wave heights for most of next week, likely peaking Mon/Tues in the 8-10ft range.

GFS has a slightly less persistent system, with the new front bringing a large pulse of S swell Mon into the 8ft+ range and a slow easing  into Tues/Wed. 

With broad model agreement odds are firming we’ll see a significant S swell event this weekend and into early/mid next week. Still a ways to go though before this storm forms, so check back in on Wed and we’ll run the ruler over it again.

Seeya then.