Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed Mar 20th)

Features of the Forecast (tl;dr)

• Spike in S-S/SE swell Thurs with S-SE winds easing through the a’noon
• Small, fun weekend with light winds favouring S swell magnets
• Small start to next week with light winds
• Moderate S swell pulses Tues/Wed next week although winds may be a problem
• Looks like small surf heading into Easter weekend

Recap

A mix of swells yesterday with some lingering S/SE groundswell and E/NE swell building up to 4ft surf with the occ. bigger set. Reasonable conditions early before NE winds freshened during the day, adding NE windswell into the mix. Mostly E/NE and NE swells this morning in the 3-4ft range with glassy/lumpy conditions under light N’y winds (NW-N/NW shifting W/NW) in most places with a S’ly change running behind schedule (into Green Cape before dawn but still not into Ulladulla at 9am).

E/NE-NE swell getting sizey through yesterday a'noon

This week (Mar 20-22)

A front linked to a low passing under Tasmania  and a trough linked to ex TC Megan in the Northern Territory are making their way up the NSW South Coast at present, bringing a stiff S’ly flow, with a strong high pressure belt running at Summer latitudes anchored by slow moving cells near New Zealand and in the Bight. The NZ high has generated a useful fetch of tradewinds in the eastern swell window, which has maintained E’ly swells in the sub-tropics, E/NE in temperate regions. That trade fetch breaks down in the short term before rebuilding again at more Northern latitudes. We’ll see some frontal activity over the weekend before another strong, blocking high sets up a ridge next week. 

Not much change for the short run - stiff S’lies to start and a spike in mostly short range S swell with raw size to 5-6ft at S facing beaches. The trough and associated fetch does move away quickly so we’re expecting a quite steep roll-off in size through the day and an easing in local winds with it. Winds should ease to 10-15kts through the a’noon and size drop down to 3-4ft at S exposed breaks, smaller elsewhere. E/NE swell will offer some top-up energy in the 2-3ft range but that will also be on an easing trend by close of play.

Easing blend of swells into Fri with S-S/SE swell fading from 2-3ft back to 2ft or less and E/NE swell also becoming slower around the same size. Winds should be good for the morning with light/variable breezes eventually ending up as weak NE seabreezes.

This weekend (Mar 23-24)

Still looking small for the weekend with light winds offering up good conditions though both days and favouring swell magnets, which is fortunate due to the lack of swell.
As mentioned on Mon, there is quite a bit of frontal activity below the continent, with mostly poorly aligned, zonal fetches. In the absence of any other swell sources though, that should see some flukey S swells over the weekend. Sat starts small, less than 2ft with some minor S swell that perks up later in the a’noon, possibly throwing up some 2-3ft sets at S magnets under light seabreezes. Just be aware a weak trough looks to bring a light S-SE flow south of Jervis Bay if you plan to travel. We’ll finesse that on Fri.

That small pulse should hold into Sun morning , before easing with light morning land breezes and a’noon variable breezes under a weak, troughy pressure environment. Don’t expect much away from swell magnets this weekend.

Next week (Mar 25 onwards)

Expect that light wind tiny swell combo to start off next week as that weak, troughy area lingers about the Sydney/Central coast region.

Stronger frontal activity tied to robust lows passes into the southern swell window Sun/Mon (see below) and Mon/Tues so we’ll see some stronger S swell pulses likely Tues/Wed, penciled in around 3ft at S facing beaches, bigger on the Hunter and other magnets.

Winds look OK Tues morning before a troughy change brings S’ly winds and these will become entrenched sou-easters likely through Wed and Thurs as the large high pressure cell near Tasmania sets up a ridge along the NSW coast.
We should see that ridge relax into the Easter weekend with the blocking high shutting down the S swell window. 

Looks like small swells into Easter although ECMWF is suggesting an inland trough focussing a NE infeed along the temperate NSW Coast, with chunky NE windswell a possibility, although accompanied by onshore winds and likely bad weather. 

We’ll see how that looks on Fri.