Sydney Hunter Illawarra Forecast by Steve Shearer (issued Wed May 29th)

Features of the Forecast (tl;dr)

• Low point in energy Thurs with small S and NE swells and freshening N’ly winds
• Developing NE windswell Fri with winds swinging NW in the a’noon.
• Early SW winds Sat, tending S-S/SE and freshening as trough of low pressure deepens off the Illawarra, S/SE swells building late
• Dynamic outlook Sun with plenty of S/SE swell and small E/NE swell
• Winds may shift offshore Sun as low moves south
• Mon looks good with offshore winds all day and a blend of sizey S/SE and E/NE swells
• Easing swells Tues into Wed with offshore winds
• May see S/SE-SE swells develop later next week as low moves back out into the Tasman- check back Fri for latest update

Recap

Dreamy conditions and what seems like endless lines of S swell continued through yesterday in the 3-5ft range with some great surf to be had if you could find somewhere handling the long lines. Today is definitely on the eases with smaller lines to 3-4ft at S exposed breaks and light winds tending N’ly through the day. A very nice run of long range S-S/SE groundswell.

Still some lines of groundswell for the dawny

This week (May 29-31)

The polar low which provided such a run of S’ly groundswell  is now well out of the picture and while we wait for those swells to strike Tahiti we’ve got a few smaller and unseasonal N’ly days to get through before a dynamic weekend pattern unfolds. The gist of it is large high moving into the Tasman with an approaching trough and cut-off low. The low sweeps to the south this weekend while the trough buds off and forms a trough of low pressure off the NSW Central/South coast, bringing weather, onshore winds and increased swell before the clearing offshore winds arrive late in the weekend. Details below. 

In the short run we’ll see N’ly winds freshen and to be honest, looks a layday with small swells. You’ll find a few S leftovers to 2ft at S facing beaches and we may see a few minor NE sidewinders in the a’noon but expect low energy surf zones and grovel at best.

Fri looks a better bet. The proximate N’ly fetch is a little off axis but it does extend up to sub-tropical latitudes and the this extra length as well as some small swell off the top of the high should see acute angled N-NE windswell to 2-3ft on Fri. Early NW winds should shift N/NW-N then back to NW in the a’noon as the frontal/trough system approaches. Definitely worth keeping an eye on those wind shifts.

This weekend (June 1-2)

Under current modelling, by first light Sat morning a trough of low pressure will be deepening due east of the Illawarra with just a brief window of SW winds, extending a little longer north of Sydney to the Hunter before winds clock around S-S/SE and freshen. There’ll be a marginal wave for the early, early before that wind gets up with some NE swell to 1-2ft. Once the trough starts to deepen and a proximate fetch off S/SE-SE winds extends off the Central NSW Coast we should see a rapid spike in new S/SE swell to 3-4ft, possibly bigger depending on how the fetch winds up. Much smaller waves out of the wind though, so keep expectations low for Sat.

Sun definitely has some potential. The trough of low pressure is expected to form a surface low and track SSW towards the Gippsland Coast/Bass Strait (SE into the Tasman would have been better!). Once the low axis moves south of an area winds will swing offshore and that is likely to occur at some point on Sun (GFS has the change occurring earlier, EC later in the day or even o/night). Strong S/SE swells are locked in, and size to 4-6ft is on the menu. We should also see some E/NE swell from the infeed into the low- likely pushing up into the 3-4ft range. Check back Fri for a last look at the wind outlook- there’s definitely some potential for good surf Sun as winds swing offshore.

Next week (June 3 onwards)

Monday is looking good. With the low near Bass Strait we should have an offshore outflow across most of the region- so offshore winds all day. A solid blend of S-S/SE and E/NE swells with the S/SE dominant should see more 4-6ft surf, easing through the day. Definitely pencil in Mon if you have any flexibility.

Easing surf Tues as the low sits off the South Coast and both fetches ease in strength. Winds remain offshore so expect some small fun surf Tues and Wed in the 2-3ft range.

Models do suggest the low moves out into the Tasman finally (see below), so we should eventually see some S/SE-SE swell after this occurs. Still some model divergence there, and hopefully we’ll have a full strength low in the Tasman next week. It currently looks fairly weak so we’re on track for surf to build later Thurs into Fri into the 3 occ. 4ft range. Winds will depend on the position of the low but we are likely to have to get through a period of S/SE-SE winds late next week.

Like all troughy periods with potential lows in the picture we’ll expect revisions through the short term so make sure you check back Fri for the latest look before the weekend.

Seeya then.