Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 11th March)

Best Days: Sat AM: maybe some peaky leftover short range SE swell, as local winds ease. Nothing special though. Mon/Tues/Wed: building E/NE swell

Recap: Small leftovers in the 1-2ft range both days, with light to moderate S’ly tending E’ly winds  on Tuesday, and light variable winds tending NE today. Seems to be a little more definition in the swell than was expected however surf size is still quite small.

This week (Mar 12 - 13)

Freshening northerly winds overnight may whip up a small windswell for Thursday morning - perhaps some 1-2ft waves at NE facing beaches - and we’ve got a S’ly change due to push across the coast during the day.

Model guidance is mixed on how this change will impact the coast. It seems an initial shallow change will arrive across the Illawarra around dawn, but a ridge will then push in behind it during the afternoon. This suggests moderate SW tending S’ly winds throughout the morning of only light to moderate strength (which may not quite reach the Northern Beaches or Hunter region), ahead of much gustier southerlies (i.e. 15-20kts+) from mid-afternoon onwards across all regions.

Nevertheless, surfing options will be limited anyway due to the lack of significant swell in the water, but NE facing beaches should remain clean through the morning (which is when we’ll see the most size from this NE windswell source). A very late increase in local S’ly windswell is possible at south facing beaches but quality will be low.

On Friday, a more substantial short range S’ly swell will fill in behind Thursday’s change. This should build wave heights to around 3ft+ sets at south facing beaches during the day but fresh S/SE winds will create poor conditions at those beaches picking up the energy. Expect very small waves at remaining beaches. 

This weekend (Mar 14 - 15)

The southern ridge will weaken overnight Friday so after an initial peak in size early on Saturday morning (2-3ft south facing beaches, smaller elsewhere) we’re looking at steadily easing wave heights. Expect smaller surf at beaches not open to the south, and due to the alignment of the fetch we’ll also see much smaller surf south from Wollongong. 

Saturday’s conditions are looking a little dicey in the Sydney/Hunter region, thanks to the lingering effects of the ridge which will probably anchor the airstream at the SE. This is a shame as it’ll have the most size of the southern NSW coast.

There is a chance that some locations (i.e. Northern Beaches) will see lighter SW winds in the morning, and overall winds will ease during the day and become variable. So the upshot is: expect lumpy/bumpy conditions in the morning. South of Wollongong we probably won’t see much influence from the ridge, so light variable winds are likely all day.

Sunday will consist of small leftovers from the S/SE plus a minor E/NE trade swell (courtesy of a building trade flow across the Northern Tasman Sea later this week); probably a foot or two combined at open beaches. Light winds and sea breezes will pad out much of the day but you’ll need a high volume board to make the most of it.

Next week (Mar 17 onwards)

We’ve still got a very complex forecast chart to decipher for next week. However the fundamentals of Monday’s forecast notes remain in place, and that is (1) I’m disregarding TC Pam as a major source of groundswell, mainly due to to its rapid SE path once it clears the swell shadow of New Caledonia, and (2) any surf we see next week will originate from the supporting ridge to the south of TC Pam.

To that end, check out the individual swell train breakdown for overnight Sunday and Monday: 22 second NE groundswell (although barely a foot in height - see image below).

This is what the global wave model is estimating will be generated from the core of TC Pam whilst it’s tucked up high in the Coral Sea at Cat 4 or Cat 5 strength, however the chances of this eventuating - and then producing any notable swell - is very low.

The fetch length of these core winds is very small and the travel distance is enormous, so even if the NSW buoys do pick up a faint signal, I’m doubtful that we’ll see any true cyclone swell in southern NSW (or anywhere on the East Coast for that matter).

Nevertheless, we will see a building trade swell from this overall progression through Monday, peaking Tuesday before easing on Wednesday. Currently thinking is (and I’ll revise the specifics on Friday with the latest model data) that we’ll see E/NE swell around 2-3ft by Monday afternoon (smaller earlier), reaching 3-4ft throughout Tuesday and early Wednesday before trending downwards. Smaller surf will prevail at south facing beaches, and we may not see quite as much size in the south of the state compared to the Sydney region.

These estimates are a small drop in size from Monday’s forecast notes, however over the last few days the models have made a few changes to the overall structure of the supporting ridge. It’s now expected to be aligned more NW/SE (i.e. with the primary fetch being E/SE thru' SE), which is aimed moreso up into the southern Coral Sea. What this means is that rather than a relatively even spread of E’ly groundswell across the greater East Coast, we’ll see the biggest waves in the north, with smaller wave heights with increasing southerly latitude. 

As for local winds, it’s still quite some time away but a moderate southerly change is expected around Tuesday but we’ll hone into the finer details in Friday’s notes. 

Other than that, there are no other major swell sources in the long term models. A reasonable frontal progression (associated with Tuesday’s change) will keep our south swell window active, and Tropical Cyclone Nathan - currently up in the Far Northern Coral Sea - looks like it’ll remain well and truly outside of our swell window for quite some time. As such, the enhanced trade flow associated with TC Pam is our primary source of (quality) swell for the forecast period. 

See you Friday!