Sydney Hunter Illawarra Surf Forecast by Ben Matson (issued Wed 19th July)

Features of the Forecast (tl;dr)

• Strong S'ly swell Thurs with early offshore winds
• Easing S/SE tending SE swell Fri with early offshore winds
• Strong though (generally) wind affected S'ly swell Sat
• Light variable winds and strong E/SE swell Sun, easing Mon
• Plenty of swell for next week

Recap

Small leftovers on Tuesday have been replaced with building south swells today, initially 2-3ft at south facing beaches this morning but now pushing 4-5ft, with larger sets across the Hunter. Beaches not open to the south are however much smaller. Early offshore winds are now around to a moderate southerly.

This week (Jul 20-21)

Looks like we’ve got an upgrade in store for Thursday’s size. 

Today’s swell is trending up nicely and with the low still very active in the southern Tasman Sea earlier today, we’re probably looking at a peak in the current swell cycle Thursday morning. In addition to a S/SW surge pushing up the eastern Tasmanian coast, there’s also a nice slingshot around the bottom of the low in the central Tasman, which should provide a little more SE in the swell direction by Friday too.  

Even better, we’ve got light morning offshore winds on the cards for Thursday thanks to a weak ridge of high pressure. They’ll swing to the north by lunchtime and fresh - especially south from Sydney - so aim for a morning session for the best conditions.

However, an evening/overnight NW flow is likely as another front rears up from the west, so keep an eye out for a late improvement in conditions (the extra few hours of summer sunlight would be of much more benefit in this scenario, though).

As for size, we’re looking at 4-6ft sets at south facing beaches, easing through the day, though smaller elsewhere, depending on exposure to the south. Expect solid 6ft+ sets across the Hunter and at the offshore bombies.  

A general easing in size will continue through Friday though the slingshot SE fetch off the bottom of the low should maintain 4ft+ sets at beaches with good southerly exposure (smaller elsewhere, and with a slight easing through the day). Aim for an early session with moderate W/SW winds preceding a gusty S/SW change as a front pushes up the coast. It’ll bento the South Coast mid-morning and Sydney by lunchtime.

This weekend (July 22-23)

We’ve got a few swell sources for Saturday.

Friday’s front looks pretty robust, and will contribute 4-5ft sets at south facing beaches (bigger in the Hunter) however an associated S/SW flow adjacent the coast will maintain average conditions at exposed spots. We may see a few select windows of early, brief W’ly breezes (i.e. Northern Beaches) but the surf will be a little wobbly for the most part.

As always, beaches not completely open to the south will be much smaller (for reference, Sat's S'ly swell looks more directional than the current event), though these spots will handle the wind better.

Saturday’s southerly swell will then ease steadily from the afternoon into Sunday. 

However, we have another swell on the way for the weekend, arriving potentially as early as mid-late afternoon Saturday, but showing best thru’ Sunday. It’ll be strong E/SE energy, originating from gales exiting western Cook Strait (between NZ’s north and south islands) that are modelled to crop up from about Thursday onwards (see below). The fetch looks pretty good so I’m expecting a broad coverage of 4-5ft sets. Let’s fine tune on Friday.

As for conditions, Sunday’s looking really nice with light variable winds and sea breezes. So, well worth your time and attention.

Next week (July 24 onwards)

Next week’s still looking pretty dynamic with a whole range of systems on the boil. 

Easing E/SE swells from Sunday will persist through Monday, but lingering low pressure in the Tasman Sea looks like it’ll generate a few small fetches that’ll provide minor background S/SE energy through the first half of the week. 

A strong front is modelled to push through the region early/mid week with the potential for a punchy S/SE groundswell around Wednesday and/or Thursday, while a mobile synoptic pattern in the Southern Ocean will ensure a continuation of long period S’ly swells for exposed spots. 

So, plenty to look forward to - we’ve just gotta dial in the specifics, which we’ll do on Friday.