Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 7th April)

Best Days: Difficult to have confidence in best days because every possible swell is pretty flukey. Wednesday is probably the best chance with a flush of S'ly groundswell. 

Recap: A building S’ly swell Saturday provided fun waves to south swell magnets into the afternoon and through Sunday, up to 3ft+ across the Hunter though smaller across most south facing beaches in Sydney, between 2ft and very occasionally 2-3ft. Winds were light so conditions were clean. Wave heights have eased throughout this morning, with early light winds tending N/NE. A small new S’ly swell is building across the coast this afternoon.

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This week (May 8 - 11)

In Friday’s notes I had expected another frontal passage south of Tasmania (over the weekend) to kick up a renewal of S’ly swell this afternoon and into tomorrow. Whilst buoy data is promising, there’s not a lot of new size showing at the coast so confidence has dropped that we’ll see anything appreciable in the next 24 hours.

Assessing the hindcast data, and it’s a difficult call. The weekend's fetch was broad and very strong - upwards of 45kts - but it was very poorly aligned within our swell window. The models aren’t picking up any size at all over the coming days but that doesn’t mean we won’t see waves - flukey south swells often produce good surf at a small number of reliable swell magnets and this is still a distinct possibility for Tuesday. 

If you have to hedge your bets, the Hunter coast is best positioned for this energy and stands the best chance to see inconsistent 2-3ft sets. However, for the most part expect tiny surf across most Southern NSW beaches, even south facing beaches throughout Sydney are more than likely to dip out in the size department. There may be some small NE windswell in the mix too but nothing overly special. Local winds will be light so conditions will be favourable.

A powerful cut-off low approaching Tasmania this afternoon looks incredible in single-step synoptics (see chart below) but the reality is that it’s moving too quickly to the east, perpendicular through our swell window. Surface wind strengths will eventually reach 60kts+ but only as it is whisked through the periphery of our swell window, so we may see a brief flush of long period south swell on Wednesday - but again, it’s likely to only favour reliable south swell magnets at best.

I’ll go out on a limb and call 3-4ft+ sets across Hunter coasts on Wednesday, with waves around 3ft across Sydney’s south facing beaches though much smaller surf elsewhere. Yeah, this is probably overly optimistic, but in all honesty, I’m only going to give this a low confidence rating. Again, local winds will be light so conditions will be favourable. 

A trough off the SE Qld coast will push south over the coming days, aiming a moderate E’ly tending NE fetch into our swell window though the resulting wind strengths will keep a lid on prospective wave heights. We should see some peaky E/NE swell building through the second half of the week though I can’t see much more than slow 1-2ft waves at most open beaches. Winds will veer offshore and strengthen so there’ll be nice conditions on hand.

It’s worth pointing out that the EC solution tightens up the head of the fetch later Wednesday well off the Mid North Coast (more so than the other models), kinda aimed into our swell window. It eventually pushes the trough too fast to the east, but I couldn’t rule out future model updates swinging this back in our favour a little more. So let’s keep an eye on that in Wednesday’s notes.

Otherwise, we have an enormous, almighty cold outbreak on the way for the weekend (across the Eastern States) in the form of a deep cut off low. Interesting, this system is expected to park itself over Bass Strait - and smash South Oz, then Tasmania, then Vicco with arctic southerlies - but the models are hazy as to how this will develop inside NSW’s swell window. 

Most of the action relative to us will occur over the weekend and early next week, but there’s a suggestion for a small, brief S/SW fetch exiting eastern Bass Strait overnight Thursday that may generate a small S’ly swell for Friday. It’s a long shot, but let’s review on Wednesday. Otherwise, expect very small E/NE swells and howling offshores to finish the working week.

This weekend (May 12 - 13)

One thing is for certain this weekend: it’s going to be windy, and pretty chilly.

The complex cut off low low forming to our south-west is showing all kinds of possibilities though I’m leaning towards tiny surf and gusty offshores Saturday, and building windswells on Sunday as gale force southerly winds develop parallel to the South Coast. Monday’s likely to see the peak of this event.

There’s a chance that some locations - north from the Illawarra - may see a period on Sunday of building S’ly swell and persistent W’ly winds just before they swing S’ly - but in general any swell increase will likely be accompanied with poor conditions.

For now, don’t get your hopes up as there’s just too much variation in the models. I’ll have a better idea on Wednesday. 

Next week (May 14 onwards)

This cut-off low will enter the Tasman Sea as a - you guessed it - Tasman Low later in the weekend, and will consequently dish up a large south swell for the start of next week. At this stage, it’s quite possible we’ll see a windy 8-10ft south swell across exposed spots on Monday, easing through Tuesday, so protected points and southern ends will be your saviour. 

Let’s fine tune the specifics over the coming days.