Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Mon 23rd May)

Forecast Summary (tl;dr)

• SE winds Mon, with SSE groundswell and short range SE swell on offer
• Lighter SW winds Tues AM with continuing small SSE groundswell and small E/NE tradeswell
• Favourable winds Wed with mix of tradeswell and easing SSE swell
• E/NE trades well Thurs/Fri mixed with small S swell and light winds
• Bigger E/NE swell on offer Sat/Sun as low drifts southwards, stay tuned for revisions
• Winter style cold outbreak on the radar mid next week

Recap

Sat morning saw the cleanest surf go the weekend with a brief window of offshore winds grooming around 3-4ft of SE swell before winds tended SE and surface conditions got very scrappy, very quickly. Surface conditions Sun were mostly hampered by those persistent winds with size easing a notch into the 2-3ft range. Surf has maintained that size into the start of the working week with rain squalls seeing offshore winds early, before winds tended S then SE. Wet conditions have been a constant across the region, in fact across most of the East Coast.

Fully contestable on a Mon morning

This week (May 23-27)

A large (1031 hPa) high has been incredibly sluggish over the weekend, barely moving from it’s position over Tasmania, and as such a ridge along the East Coast has only slightly began to break down. Sub-tropical troughs and the remnants of TC Gina near New Caledonia are maintaining a deep E’ly flow through the Coral Sea while the last in a series of powerful cold fronts are now sweeping up past the South Island of New Zealand with small S to SSE swell pulses to come over the next couple of days from this source.

In the short run and light winds are on the menu- for the rest of the week actually, as the high slowly meanders out into the Tasman, the ridge weakens and a series of small troughy areas just adjacent to the coast and offshore maintain weak, unstable pressure gradient areas.

The short range SE swell will be easing back and we’ll be relying more on longer range, long period energy from the Deep South, at the extremity of the swell window, so expect inconsistent and flukey sets through tomorrow, with background energy to 2ft and sets to 3ft+ at S facing beaches. Some deep water and exceptional S swell magnets will see bigger 4ft sets but most beaches will be far smaller than that as the short range energy eases back in the mix.

That size will ease back further into Wed, with long period sets to 2-3ft at S swell magnets, much smaller surf in the 2ft range or less elsewhere. Small amounts of short period E/NE swell from the bottom edge of the E’ly wind field will see some peaky energy to 2ft in the mix, more prominent through the a’noon. Light sea breezes are likely through the a’noon with morning land breezes extending well into the late morning or lunchtime.

By Thurs we’ll be into a slightly more defined NE pattern though with morning land breezes still well entrenched there’ll be classic Autumn conditions into the late morning/lunchtime. More flukey long period S to SSE swell energy is expected- after such a long period of being highly energised the Southern Ocean will take a while to settle, hence the long tail of this S swell event. Traditionally, swells from these South Island sources with fetches aimed mostly at Tahiti tend to be extremely flukey, so I’m inclined to be wary of model guidance. With that caveat, with light winds it might be worth a look around Thurs at S facing beaches. More E/NE swell to 2ft+ will pad out open beaches during the day.

Light winds continue into the end of the week as the unstable, troughy area lingers off the Coast. A surface low is expected to form off the QLD coast Wed/Thurs and drop south, pushing the E’ly windfield more directly into the temperate NSW swell window. That should see a modest increase in E/NE swell through Fri- up into the peaky 2-3ft range through the day, bigger 3ft in the north of the f/cast region. All in all, with favourable winds there should be some small fun, albeit flukey waves on offer through the week.

This weekend (May 28-29)

Quite a bit of action ahead for this weekend, and the models are still moving around a bit run to run, so it’s likely there’ll be revisions on Wed and Fri.

It’s basically a competing synoptic pattern with a La Niña sub-tropical low tracking south from the Coral Sea while a more seasonal cold outbreak arrives from the South, bringing a SW to W flow from the interior. How those two competing air masses evolve will determine the state of surf this weekend.

Swell from the E/NE-E is most definitely on the menu as the low tracks south, with a broad fetch aimed increasingly at temperate NSW.

That should see surf build from that source during Sat, likely from 3ft, up into the 3-4ft range during the day, with early W’ly winds tending SW to S as the trough along the coast and inland starts to be squeezed from the low in the East and front approaching from the West.

The pressure squeeze increases Sun, with freshening SW to SSW winds and surf likely muscling up into the 3-5ft range as longer period E/NE swell makes landfall. There should be plenty of fun options this weekend.

Next week (May 30 onwards)

The sub-tropical low and troughy area off the NSW coast combine and track south into early next week, with a SW flow tending NW as the approaching cold front brings pre-frontal winds. That will see E swell easing quite quickly through the day, extending into Tues.

Models are mixed on whether we will see some S swell from a small fetch on the southern flank of the retreating low, possibly Wed. We’ll update that this week.

Following that looks like a hard and true W’ly wind as the front sweeps across NSW through Wed/Thurs with small leftover E swell most likely.

A cold front hard on it’s heels looks more likely to bring a blast of new S swell as we head into the first week of June, with the blast of cold air the first respite from La Niña conditions since late October. We’ll see whether that heralds a more sustained change of pattern.

Check back Wed for the latest.