Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed 27th Apr)

Forecast Summary (tl;dr)

• Surf becoming small Thurs/Fri with minor NE windswell
• Small boost in E/NE tradewind swell Fri, lingering at low levels over the weekend
• S’ly swell spikes Sun PM with fresh SSW winds
• Fun S swell Mon, with winds easing
• Fun looking E/NE swell Tues/Wed next week with light winds

Recap

S’ly groundswell filled in late yesterday and overnight with a slightly more S/SE orientation on buoy data and on ground observations today. That is seeing inconsistent sets to 3ft across most of the region (at S exposed breaks ) with bigger 4ft surf on the Hunter. Conditions were clean early with light offshore breezes, now tending to variable then light NE sea breezes.

Long lines on the Hunter

This week (Apr 27-29)

No great change to yesterdays notes. A large 1029 hPa high pressure system is sitting smack bang in the middle of the Southern Tasman Sea in a strengthening phase, with a series of tropical troughs in the Northern Coral Sea beginning to expand Tradewinds through the tropics.

This will see a N’ly pattern established over the f/cast region for the rest of the week with a trough/low bringing a S’ly change late Sat. The trqdewind pattern extends southwards through the end of this week into the weekend, eventually bringing E/NE swell to temperate NSW, slowly blending in with NE windswell over the weekend and into next week. 

Small mixed bag to round off the working week. NE winds tomorrow bring a small quantity of NE windswell, mixed in with a few leftover S swell trains. Size in the 2ft range with a few bigger sets at swell magnets. Expect early N to NW winds to freshen and tend NE early, before clocking around to a more N’ly direction late in the day.

The proximate fetch of NE winds next to the temperate NSW backs down Fri and tends more N’ly as a trough approaches, so NE windswell will back down a notch. Expect some weak 2ft NE windswell Fri with a possibility of more favourable NW winds developing through the southern half of the f/cast region during the a’noon. Short period E/NE swell will add some minor energy to the mix as well, not exceeding 2ft. A few peaky options on the beachbreaks are likely.

This weekend (Apr 30 - May1)

Saturday looks better now with winds tending N then NW and possibly WNW through the day in response to the approaching trough. Surf will remain on the small side with mixed NE windswell and E/NE tradewind swell. That will remain in the 2ft range, but with clean conditions there should be enough energy for a fun, small wave grovel. A late S’ly change is on the cards, although possibly tending to SW winds later, especially on the Illawarra and a storm is on the cards as well. If you can navigate those wind shifts there’ll be some small surf to ride.

Sundays S’ly change and S swell now looks downgraded compared to yesterday. A trough and small low quickly scoot away to the SE through Sunday. Early fresh SSW to S winds will lay down through the a’noon, becoming light SSE to SE by close of play.

Surf-wise we’ll see a continuation of small E/NE tradewind swell with spike in short range S swell in the 2-3ft range through the a’noon. There’s a fair bit of model variance around this spike in S swell with GFS suggesting a strong, proximate fetch of S’ly winds which would see a stronger pulse up into the 3-5ft range, bigger 4-6ft on the Hunter. Let’s take the conservative EC option for now, and revise (upwards hopefully) on Fri.

Next week (May 2 onwards)

Plenty of E swell ahead next week as Tradewinds and a sub-tropical low drifts south through the South Pacific slot (see below).

Broad tradewind fetch in the South Pacific with embedded sub-tropical low generates plenty of E/NE swell next week

Winds should improve quickly on Mon as a high cell moves over Southern NSW, with a lingering S’ly flow becoming light through the day. E/NE swell is expected to pick up into the 3ft range, with leftover S swell mixed and dropping out through the day.

 Mid period E/NE swell muscles up further through Tuesday, pushing up from 3-4ft, into the 4-5ft range at E exposed breaks. Light winds should tend to light sea breezes, under weak pressure gradients so pencil Tuesday in if you’ve got flexibility. It looks good/great.

An approaching cold front sees winds tend NW through W on Wed and with continuing 3-5ft of E swell on offer it looks like one to mark out. Expect offshore winds to last through the mid/late morning and possibly into the a’noon before a S’ly bias kicks in as the front passes through into the Tasman.

Through to the end of next week and we’ll see a slow roll-off in size from the E as the extended tradewind fetch gradually contracts Eastwards out of the swell window. E swell should pad out next week with winds tending S’ly through Thurs/Fri.

A small troughy feature off the coast will be the potential curve ball. This could possibly generate some local SE swell depending on it’s position through the end of next week, as well as modifying local winds.

We’ll see how that shapes up on Friday.

Some intense frontal activity below the SE of Aus is likely to see some pulses of refracted S’ly groundswell early in the week beginning 9/5.

Check back Fri and we’ll see how that is shaping up.