Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed 11th Oct)

Features of the Forecast (tl;dr)

• New S'ly swell Wed PM, early light winds and NE sea breezes (northern corners for the late session)
• Morning peak in good quality S'ly swell Thurs with strengthening N'ly winds, late NE windswell
• Building S'ly swell Fri with generally good winds-offshore early and a’noon seabreezes
• Tricky weekend, likely easing S'ly swells Sat, rebuilding Sun PM
• Potential low in Tasman next week may offer solid S to SE swells but still early days- check back Fri for revisions

Recap

S swells yesterday hung in the 3-4ft range at S exposed breaks most of the day (bigger 3-5ft on the Hunter). Morning offshore winds were reasonably widespread with clean conditions before winds kicked up from the S to SE through the day, blowing out S facing beaches. Today has seen an easing in size as S swell ebbs with slow sets to 3ft across most of the region and a few bigger 4ft sets on the Hunter. Light winds early with some leftover bump and wobble  on it, before winds kicked up from the NE. A late kick in S’ly groundswell is still on the cards, although moreso expected in the morning. 

Bit gurgly but workable options on an easing S swell

This week (Oct 11 - 13)

Moderate strength high pressure (1025 hPa) is drifting NE into the Tasman with a strong polar storm well SW of NZ exiting the swell window. That should see a settled short term before another complex trough and frontal system pushes north along the coast tomorrow with a stiff SW-S change. More rapid wind changes into and over the weekend under a very mobile, troughy pattern with some potential next week for a surface low to form in one of the trough lines. Details below.

In the short run and the storm passing off the ice shelf delivers a nice package of long period S swell which should linger well into the midday before easing off. 3-4ft sets are expected at S facing beaches with a few bigger bombs at some of the better magnets. Early winds look good- W/NW-NW before freshening from the N/NE to N as the trough/front approaches. There’ll be some real strength to them in the a’noon, possibly in excess of 30 knots with a moderate NE windswell developing through the a’noon, likely a notch bigger than Mondays expectations. 

The timing of the front and wind change means most of the N’ly fetch gets rapidly shunted eastwards overnight Thurs with just small NE leftovers around for Fri morning (a few 2ft set) under mod offshore W/SW-SW winds. Those winds look to ease pretty quickly from midday, tending to light/mod a’noon seabreezes. A mix of S swell trains, predominantly shorter period S from the proximate fetch adjacent to the Southern NSW Coast should see surf build into the 3-4ft range by mid morning. Should be some fun waves around although the Hunter coast is likely to be a bit wind affected by S’ly bias in the winds until the sea breeze kicks in.

This weekend (Oct 14 - 15)

More certainty for the weekend now with Sat morning looking good. Another front and inland trough should see a nice offshore flow for the morning- W-W/NW- with mid period S swells in the 3-4ft range, a notch bigger on the Hunter. S facing beaches all along the region should be nice and clean before light seabreezes from the NE kick up in the a’noon. 

Winds still look a bit tricky for Sunday as a trough lingers about Jervis Bay. Under current modelling we can pencil in a morning  offshore flow (possibly more SW on the Illawarra) before variable a’noon breezes. We’ll finesse that on Fri if the trough moves north. Saturdays S swell looks to ease a little into Sun morning (2-3ft) but a broad front passing SE of Tasmania early Sun should see another kick in S swell to 3-4ft later Sun a’noon.

Next week (Oct 16 onwards)

The troughy pattern lingers into Mon with some intriguing possibilities. First up, there will be fun S swells in the water Mon morning from the weekend’s frontal activity, likely in the 2-3ft range early, with a longer period pulse after lunch a notch bigger. Get in early for the best chance of light winds.

Model divergence is pronounced so we’ll be back for revisions but one major model (EC) is suggesting the development of  surface low in the Tasman early next week, possibly lingering for a few days.

Under this scenario we’d be looking at a steep increase in directional S swell late Mon, with some size from the S into Tues before moderate S/SE-SE swells into Wed, possibly Thurs. 

GFS has a less enticing offering with the trough lingering about the coast, although focussing SE winds onto the coast later Mon and then holding steady with E’ly winds feeding into the trough line into the middle of the week, suggesting SE-E swells Tues-Thurs with winds improving from Wed.

Longer term and more frontal activity below the continent later next week suggests more S swell into next weekend.

Lets see how things are shaping up on Fri. Would be great to see a full fledged surface low in the Tasman Sea but it’s too early to get any froth going.

Seeya Fri.