Large, steadily easing swells with light winds
Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Friday 14th February)
Best Days: Light winds and large, steadily easing swells all weekend. Fun S'ly swell Mon, then a nice SE swell Tues/Wed. Plenty of S'ly swell later next week and weekend.
Recap: Wow, where do we start. Well, Thursday of course - which generally held 3ft+ of residual E/NE swell for almost the entire day, though very late afternoon/early evening started to see a few bigger sets of leading-edge cyclone swell from the NE. Winds were light to moderate onshore all day, so workable but not amazing on the surface. As for today, it’s been a bit of a wild ride. Overall, the surf has panned out kinda how I anticipated, though more rapidly in timeline - and there were large differences in reported size between coasts, as it seems the Northern Beaches has been an outstanding swell magnet for this entire event. Starting out with 4-6ft surf here, we saw smaller wave heights through the Hunter (as is common under NE thru’ E/NE swell events), but interestingly - and uncharacteristically - the Illawarra saw much smaller surf this morning around 2-3ft (Cronulla was also smaller than the Northern Beaches, but this is common under such swell directions). Although step-ladder sets were expected through the day as the swell increased, we’ve seen an initial peak in size earlier than I expected - and fractionally higher than forecast too - with some locations across the Northern Beaches pushing 10ft+ at times. But, despite the swell trend kicking in elsewhere, it’s smaller in size near 8ft+ across other coasts. Either way, the cyclone swell from (now, ex-) TC Uesi is very strong, and with moderate S/SW (Hunter/Cenny Coast) thru’ S/SE (Sydney, Illawarra) winds on offer, options are limited to sheltered southern ends and points that can handle this volume of water.
This weekend (Feb 15 - 16)
A couple of points on wave heights distribution from coast to coast, or even surf break to surf break.
Today's impressive cyclone swell was out of the NE thru' E/NE, a rare direction for events with these kinds of mid-large swell periods (Tp 16 seconds). As such, it was a great opportunity to see how various coasts responded to this size/period/direction combo.
Interestingly, across the Manly stretch - where our surfcam has an excellent high vantage - it was incredible to see 10ft+ lines steamroll through to the southern end of the Bay (powering into South Steyne), but effectively bypass the Queenscliff Bombie, the regional big wave location that typically enjoys large, long period groundswells - though usually from the east or south-east.
What's fascinating about this is that even though there's only half a kilometre between the two spots, the bathymetry steered this particular swell combo around the bombie and straight into the neighbouring break.
Anyway, let's get back to the forecast and look at the synoptics.
Ex-TC Uesi decoupled its fetch as it underwent extra-tropical transition on Thursday as it approached Lord Howe Island (which got smashed with 83kt wind gusts). We did see a secondary E/SE fetch develop later yesterday and this morning on ex-TC Uesi's southern flank, but it was travelling reasonably fast through the swell window at this time and this means the swell generated will be short lived.
Now, in assessing the weekend’s potential we can use Northern NSW as a reasonable proxy for swell trend, because it was further upstream to the initial swell source and therefore we’ll see a similar trend play out in Southern NSW. Though, the (cyclone) swell front was much more defined across Southern NSW, partly because the pre-existing background trade swell was larger across SE Qld and Northern NSW, but also because the cyclone swell travelled farther (to Southern NSW) and therefore had a little more time to become properly organised.
So, with Northern NSW still pushing 10ft sets for the majority of today, we can expect today’s size across Southern NSW to plateau overnight, and hold into Saturday morning. Though, I feel it will be largest early morning, and then trend down during the day. The earlier-than-expected peak of large waves today also steers my thinking in this direction too.
Adding further complexity into the mix will be the additional E’ly tending E/SE swell that’s currently being generated in our near swell window. It’ll fill in overnight and provide strong surf for most of Saturday though again, wave heights will likely peak in the morning and ease into the afternoon.
As for size, we need to be a little careful with our expectations, because (as per the South Steyne/Queenscliff Bombie example above), today has shown that these kinds of long period events can be steered efficiently into some locations, but less efficiently into others. This is dependent on what your coast’s preferred magic numbers are - something that’s not particularly well understood at a local level.
Therefore, not every location may pick up the maximum size from this swell direction. And, as the swell direction will be slowly swinging clockwise, locations that were very responsive today may be less responsive tomorrow.
Anyway, I still think many exposed coasts will pick up occasional 8ft sets on Saturday morning, and one or two swell magnets could see occasional 8-10ft bombs around dawn. But I think we’ll see size easing to 6-8ft by lunchtime and early afternoon, and it'll probably become a little smaller late in the day too.
By Sunday morning, exposed beaches will be down to an inconsistent 4-5ft and the afternoon will see a further easing to about 2-3ft.
As for conditions, we’re looking at light variable winds across most coasts both days, early offshores then afternoon onshores but with strengths under 10kts.
A weak front will clip the Far South Coast overnight Saturday we may see moderate S’ly breezes in this region on Sunday but I don’t think it’ll affect anywhere north from about Ulladulla.
So in short, great conditions with very large but steadily easing size all weekend. Get into it!
Next week (Feb 17 onwards)
Modest trades in the South Pacific east of New Zealand longitudes will maintain background E/NE swell for much of next week, though no major size is expected.
The first half of next week will see light variable winds across the coast under a slow moving trough of low pressure. Tuesday afternoon is at risk of freshening NE breezes but I don’t think they’ll amount to much.
Monday will see small southerly swells, generated by the front expected to clip the Far South Coast overnight Saturday. This should kick up 2-3ft sets at south facing beaches, though it’ll be much smaller elsewhere due to the swell direction.
On Sunday, the same front will then merge with the remnants of ex-TC Uesi, near the SW tip of New Zealand’s South Island. Initially this will generate S/SE gales in the south-eastern Tasman Sea, but as the merged system travels slowly eastwards over the South Island, we’ll see a broadening of SE gales just south of the South Island. All of this development will conveniently remain within Southern NSW’s SE swell window, and I think we’ll see some good surf from it.
However, the models have cooled a smidge since Wednesday’s update so I’ve pulled back wave height estimates. Surf size will build slowly from the SE through Tuesday morning into the 3ft range, before pulsing 3-5ft late afternoon and perhaps early Wednesday, then easing into the afternoon. Locations further south are likely to see the upper end of this size range (more than northern locations) but either way there’ll be plenty of good options on hand.
The coastal trough will probably evolve into a closed low off the South Coast overnight Wednesday and Thursday is looking at a punchy S’ly windswell with accompanying southerly gales. Current expectations are that this low will hang around for a few days, so right now there’s a reasonable chance for solid S’ly swells on Friday, with improving winds as the low moves a little further away from the coast.
That’s about it for now - have a safe weekend, see you Monday!