Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed 5th Oct)

Forecast Summary (tl;dr)

• Pulses of small S’ly groundswell from Wed-Fri this week
• Onshore flow develops Wed with short range E-E/NE swell tending to NE swell Thurs-Sun
• Plenty of E/NE tradewind swell developing through Mon-Wed next week with light winds
• Uncertain wind outlook from Sat due to coastal trough and possible low likely generating chunky SSE swell Sun-Mon
• Stronger E’ly swell on the radar from Wed-Fri next week from large E’ly fetch in South Pacific, check back Fri for updates

Recap

Plenty of fun leftover SE-ESE swell yesterday which hovered at the top end of f/cast expectations in the 3-4ft range, clean early under light NW winds, which tended NE in the a’noon. Today has seen an E’ly flow develop as a new high pressure ridge sets up along the coast. Scrappy, onshore 2-3ft surf across the region is on the menu. 

Clean leftover ESE swell yesterday provided fun surf

This week (Oct 5-7)

Another huge Indian Ocean cloud band is drifting across inland Australia, anchored by troughs, while a strong (1036hPa) high shifts into position SE of Tasmania. Strong fronts have already transited the Tasman Sea with some long period S-SSE swell pulses incoming. Those pulses will be concurrent in a more dominant building E/NE-NE windswell episode, through the rest of the week and into the weekend. Lots of action next week as both our Eastern and near Southern swell windows fire up. Read on for details.

Nor-east winds kick in tomorrow at mod/fresh levels and a local E’ly windswell from todays high pressure surge. Through the day that swell will tend more E/NE as the proximate fetch rotates. Size in the 3ft range is expected from this source and we’ll see mid/long period S swell in the 2-3ft range at S facing beaches. 

The northerly pattern remains entrenched for Friday, as the inland trough system approaches and pressure gradients tighten. There may be a slightly more N’ly tilt to winds, favouring S facing beaches. Expect continuing NE windswell  in the 2-3ft range, building through the a’noon. Mid-long period S-SSE swell will produce some 3ft sets at S facing beaches, with energy a notch above Thursday.

This weekend (Oct 8-9)

We’re getting more clarity on the weekend outlook but winds still look very tricky as a trough line emerges on the South Coast and migrates north during Sat. The most likely outcome at present is early NW to N winds, shifting NW and possibly  W during the day. A late S’ly change can’t be ruled out as the trough clears the coast, especially in the south of the f/cast region. Surf-wise a mix of NE swell in the 3ft range and long period inconsistent SSE well with sets to 2-3ft will provide a few options.

Sunday is still looking a bit of a mystery bag, depending on the position of the trough and what looks to now be quite an intense surface low developing just off the coast. EC model shows an intense low with gales aimed at the region, which will see a fast rising S-SSE swell through the day. GFS has a more southwards located system, with morning SW-W winds cleaning up a solid increase in NE swell in the 4-6ft range from winds infeeding into the system. 

Small variations in position and intensity of such a proximate system will have large differences in surf and wind outcomes on Sunday. 

Check back Fri for the latest updates.

Next week (Oct 10 onwards)

Not much change to next weeks outlook. As Craig outlined, a serious E’ly fetch is setting up through the South Pacific and Coral Sea slot. It’s broad enough to spray the entire Eastern Seaboard with swell for the majority of next week.

In addition the low which formed in the trough line over the weekend is expected to supply S-SSE swell through the first couple of days of next week. 

Light winds are likely to set in through Mon-Wed next week as a high moves into the Tasman and long trough lingers across coastal NSW and up into QLD. 

Depending on the movement of the weekends low we’re looking at a mix of SSE and E/NE swell for Mon, with SSE swell dominant in the 3-4ft range and E/NE swell building into the 2-3ft range.

Light SE winds through Tues/Wed as the ridge sets up will see slowly increasing E/NE swell, likely up into the 3-5ft range. Pencil these days in. Tuesday will also see decreasing SSE swell in the mix.

From Mid next week we should see E/NE swell muscle up reflecting an increase in windspeeds in the fetch as a tropical derived low drifts south into the tradewind flow. We’ll have more revisions available as the system progresses but for now, we’re looking at a chunky 5-6ft of E/NE swell, with winds tending NE as the high moves out into the Tasman. Giddy up.

Longer term and the next dominant high is also moving at a very southerly latitude suggesting more E’ly quarter swell, with fronts in advance of offering up potential for some S swell possibly late next weekend or early week of 17/10.

Lots of action to look forwards to so check back in Fri for the latest update.