Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Friday 15th April)

Best Days: Sat/Sun: steadily building S'ly swells all weekend - potentially sizeable at south swell magnets on Sun - easing Mon. Generally good winds. 

Recap: Thursday morning initially delivered easing S’ly swell from Wednesday, with 2-3ft sets at south facing beaches and smaller surf elsewhere. During the afternoon, a new long period SE swell made landfall, and whilst most beaches approached the 4ft mark by the end of the day, some reliable swell magnets saw powerful sets around 6ft. Winds were light NW tending N’ly so conditions were pretty good. This SE swell peaked overnight and has eased very slowly today. Most open beaches managed 3-4ft sets in the morning but a few swell magnets once again picked up bigger 4-5ft sets, and with winds around to the W/SW it’s been nice and clean. Surf size is now a little smaller. 

Strong SE lines at Queenscliff and North Steyne this morning

This weekend (Apr 18 - 19)

There’s no change to the weekend forecast.

We’ve got a steady supply of building southerly swells on the cards, originating from two seperate fetches contained within one broader system, all associated with an amplifying Long Wave Trough. 

A series of strong fronts are directing gale force winds across the Tasmanian region right now. W/SW gales exiting eastern Bass Strait will generate a fresh S’ly swell for Saturday morning (2-3ft south facing beaches stronger around 4ft in the Hunter). 

However, the parent low below Tasmania will generate a more powerful, longer period S’ly swell for Sunday.

Because of the remote, flukey source of this swell, and the fact that much of the fetch did its swell generating in the (partial) shadow of Tasmania, we’ll see a much more erratic response across the coast (read: less confidence for the upper end of the size estimate at many beaches, usually considered to be 'south friendly'). But, many south facing beaches should still reach somewhere around the 4-5ft range, maybe 4-6ft and it’ll be even larger across the Hunter with occasional 6-8ft bombs. 

Of course, both days will see much smaller wave heights at beaches not open to the south, and southern ends will be very small indeed. So with this swell being a little flukier than the more common southerly swells (that originate from S/SW fetches parallel to the Southern NSW coast), we need to be a little more flexible in our expectations than usual. Also, I'm estimating a lot higher than the models for the weekend's surf (in particular Sunday), but I think they're not resolving the direction very well. 

Local conditions look pretty good both days under a weak pressure gradient, with light variable winds. This could be onshore at times (most likely in the afternoons, especially Sunday) though it shouldn’t be too strong so conditions are likely to remain favourable. 

Next week (Apr 20 onwards)

On Sunday morning, a small low is modeled to develop in the central/southern Tasman Sea, at the tail end of the fetch responsible for the weekend’s south swell. Whilst this won’t generate a major swell for Southern NSW, it should arrest the otherwise steadily easing trend, keeping south facing beaches in the 3-4ft range early before size falls away more rapidly into Tuesday.

Again, expect smaller surf at beaches not open to the south though the Hunter should see a few bigger bombs. Conditions look good too as a weak front approaches form the south-west, maintaining W/NW winds. 

Looking further ahead and we’ve got a period of small waves on the cards. A weak trough developing in the north-eastern Tasman Sea - which may form a closed low off NZ's north-east coast - needs to be monitored for swell potential though at this stage the fetch length and strength doesn’t look overly promising for us. 

Otherwise, a series of intense fronts and their associated low pressure systems will approach Tasmania early in the week. However it appears they’ll ride a little too far north in our (acute) south swell window, and also be more zonal (i.e. west-east) in alignment than is idea.  

We’ll probably see a series of S’ly swells glance the coast Thursday and Friday but right now they’re likely to bypass most locations and only favour south swell magnets with small surf. 

That’s about it for now.. have a great weekend, see you Monday!