Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 12th March)

Best Days: Thurs/Fri: solid rebuilding swells from the SE plus a smaller NE swell (Thurs), with morning offshore winds. Sat/Sun: rebuilding S/SE swells, plus a small long range E'ly swell. Mainly light winds and sea breezes. Mon: rapidly easing S/SE swell with a slowly easing E'ly swell, and offshore winds. 

Recap: Strong S’ly swells built through Tuesday, with 6-8ft sets at south facing beaches through the middle of the day ahead of an easing trend into the afternoon. Winds were W/SW early morning but swung gusty S/SW throughout the day. Surf size has levelled off from 3-5ft to 3-4ft today and early offshore winds are now around to a moderate S’ly.  

This week (Apr 13 - 14)

Thanks for the feedback on the change in writing style. Seems there’s more support for the old style (grumble grumble! ha).

Righto. The Tasman Low has been restrengthening close to the SW tip of New Zealand’s South Island over the last 36 hours. It’ll deliver a renewal of SE swell through Thursday afternoon and Friday morning, building from 3-4ft to somewhere between 4ft and maybe 6ft at exposed beaches, mainly those facing to the south (the upper end of this size range will be focused towards exposed reefs and swell magnets that amplify long swell periods the best). Size should ease back a little into Friday afternoon.

This size range is higher than our surf model is estimating but I’m pretty confident we’re going to see some quality long lines of strong groundswell across the region. However beaches without good southerly exposure will be smaller in size.

Also pushing down the coast on Thursday will be a brief flush of NE swell from TC Cook, which passed over New Caledonia earlier in the week and is now tracking unfavourably SE towards New Zealand’s North Island. 

Interestingly, the SE Qld and Northern NSW coasts picked up the expected size today (3-5ft sets) however after the satellite passes came through on Wednesday - showing surface wind speeds lower than model expectations - I was concerned that the swell models had over-performed, and exaggerated the potential size. Seems this wasn’t the case though, as the swell is strong and consistent across the northern regions. This will be worth hindcasting at some point in the future.

However I’m not quite as confident for the Sydney region for this swell, as TC Cook was a flukey system as it tracked through the swell window - it initially had a SW track towards the SE Qld region but then swung away to the SE, so the time spent in Southern NSW’s swell window was a little more fleeting.

Therefore I’ll maintain Thursday’s expectations for building 3ft+ sets at NE facing beaches during the day (easing rapidly Friday) but I’m only mildly confident that it’ll eventuate.

Good thing we’re expecting a decent building SE swell at the same time!

As for local winds, the southerly synoptic flow of late should ease into Thursday, providing light offshore winds at most coasts and afternoon sea breezes. Similar conditions are expected on Friday with probably a little longer for the offshore pattern in the morning. Friday looks the pick overall - we’ll see plenty of size through Thursday afternoon but the modest onshore flow will probably spoil things; Friday should see the best combo of size and winds.

This weekend (Apr 15 - 16)

So, we’ve got a three way merger expected in the southern Tasman Sea this weekend, between the Tasman Low, an advancing cold front from the Southern Ocean, and the remnants of ex-TC Cook which is expected to slide down the East Coast of New Zealand on Thursday and Friday, re-entering the lower Tasman Sea and stalling a southerly fetch for a day or so. 

Unfortunately, the eventual outcome looks like it’ll be aimed more towards Fiji so we’re looking at a glancing southerly swell over the weekend. Wave heights may dip temporarily to 3ft+ at south facing beaches Saturday morning but should rebuilding to 3-5ft throughout the day, before easing back to 3-4ft on Sunday. 

Also in the water over the weekend will be a small, very inconsistent long range E/NE groundswell generated by a sub tropical low in the South Pacific this week that has a broad high pressure system to the south, resulting in a long period groundswell making its way slowly through the region. Set waves will be very infrequent but could nudge the 3ft mark at times (building Saturday, levelling out Sunday).

Conditions should be great both days with light offshore winds and sea breezes. 

Next week (Apr 17 onwards)

The models have cooled on the prospect of another Tasman Low next week so it looks like Monday will see steadily easing S/SE swell from the Tasman Low combo, and slowly easing E’ly swell from the South Pacific system. There’s nothing otherwise showing up on the long term radar.