Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 5th September)

Best Days: Tues/Wed: fun (generally) small south swell at exposed beaches with light winds and sea breezes. Fri: building NE windswell, hopefully the models will push forward a W'ly change due after dinner (to the mid afternoon). Sun: fun S'ly swell. 

Recap: A tidy NE swell produced fun waves across open beaches on Saturday, with a wide range in surf size depending on exposure to the north-east and latitude along the Southern NSW coast. A return southerly swell - originating from a small but deep low that formed off the Far South Coast on Saturday - built late afternoon across the South Coast, providing quality 3-4ft+ waves throughout Sunday (with reports of very large waves at certain South Coast swell magnets). This swell has persisted into today without losing too much size - not as much as was expected anyway (maintaining 3-4ft against the 2-3ft forecast). Conditions have been really good for the most part with mainly offshore winds.

This week (Tuesday 6th - Friday 9th)

A broad storm track well to the south of the continent is expected to maintain small long period south swell across Southern NSW for the next couple of days. Although the winds within the storm track were not very well aimed into our swell window, the sheer breadth of the fetch, the strength of the core winds and their sustained nature is expected to tip the balance in fun of some fun surf at south facing beaches. 

Additionally, conditions will remain clean through Tuesday and Wednesday with mainly light variable winds. 

There are multiple embedded pulses within the overall swell trend for this period, and estimating the precise upwards and downwards phases is difficult. At this stage it looks like most of Tuesday will see easing swells across the region ahead of an afternoon pulse of new S’ly swell across the South Coast that should reach Sydney overnight. A second south swell is then expected through Wednesday morning, with a third slightly longer period swell due late Wednesday (and more so into Thursday). 

Our swell model isn’t resolving these swells very well, and in general I don’t have a lot of confidence in the outlook - especially if you have to schedule in a precise surf window over the coming days - but in general we should see surf size holding in and around the 1.5-2ft range as a baseline figure - very inconsistent at times - with larger pulses (late Tuesday, moreso into Wednesday afternoon and early Thursday) up to 3ft at times. And as per usual, a little more size across the Hunter region. 

Aim for the mornings for the best conditions as NE sea breezes will develop into the afternoon.

On Thursday, a broader N/NE flow will establish itself across the coastal margin thanks to a burgeoning Tasman high, and this will create problems at open beaches. However, we should see a NE windswell build from this source during Friday. At this stage 3ft sets seem very likely across exposed parts of the the Sydney coast in the afternoon, up to 4-5ft across the South Coast, though an approaching westerly change looks like it may arrive a little too late to properly benefit the coast (just after dinner time).

However, this is still four days away and it’s quite plausible that we’ll see further model runs speed up the timing of the change, allowing for a clean window of peaky 3ft waves for the late session on Friday. I’ll have an update on this on Wednesday.

This weekend (Saturday 10th - Sunday 11th)

The current forecast timing of Friday night’s westerly change is unfortunate. Whilst it’ll provide lovely clean conditions for the early Saturday morning session, it’ll also shut off the swell supply from Friday evening onwards, and will therefore result in small, diminishing waves across most open beaches throughout Saturday. 

Otherwise, the only other swell source for the weekend are W/SW gales exiting eastern Bass Strait on Saturday (behind the same front responsible for the W'ly change). They should produce a fun if somewhat directional south swell for Saturday afternoon (select South Coast locations) and Sunday (evevrywhere else). Early indications are for 3ft sets at south facing beaches, up to 4ft in the Hunter region but much smaller at locations not exposed to the south. I’ll have more on this in Wednesday’s update.

Next week (Monday 12th onwards)

Looks like we have yet another strong frontal passage through the Southern Ocean and lower Tasman Sea over the weekend and early next week that should produce a sustained run of long period southerly swell for most of next week.