thermalben

Stacks of swell ahead for Sydney surfers

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 17th May)

Best Days: Thurs: clean waves for much of the day with a new SE pulse. Sun: mix of S'ly groundswell sna NE windswell, and light winds. Mon/Tues: strong SE groundswell with good winds. Wed onwards: mix of easing SE and undercurrent of small E/NE swell with good winds. The E/NE swell may continue for some time.

Recap: Tuesday delivered a fun mix of building S’ly and residual E’ly swells, with size up to 3-4ft at south facing beaches by the afternoon, and early W/SW winds tending S’ly during the day. Today we’ve seen a smidge more size through the morning (solid 4ft sets at south facing beaches) and offshore winds creating clean conditions, with excellent surf reported at most beaches. Swell direction was generally SE.

Maroubra pumping this morning

This week (May 18 - 19)

As expected the Tasman’s enormous low pressure system didn’t produce any massive surf, due to the orientation of its strongest winds. There was a slightly better spread of surf size across the region though, owing to more SE in the swell direction than was anticipated on Monday. 

This Tasman Low is now slowly weakening and tracking towards New Zealand, and although a slightly better aligned fetch is now developing across its western flank, the low’s eastward track will preclude any major size from this source. 

As such we are looking at another S/SE thru’ SE swell glancing the coast throughout Thursday however the Northern NSW coast will probably be the biggest beneficiary, with locations south of the Hunter only expected to see glancing energy. 

That being said, I think the models are undercooking this swell, estimating only 2ft on Thursday - I’m expecting fairly solid 3ft sets at south facing beaches during the day. And conditions will be clean early with light offshore winds ahead of a weak afternoon sea breeze. Expect smaller surf size south of about Wollongong, owing to the alignment of the fetch further north (in fact, the Hunter may pick up occasional bigger waves than estimated above, owing to its slightly better angle). 

Friday looks pretty tricky at this stage. Thursday’s SE swell will be easing, but of more concern is a developing trough over the island states that’s expected to freshen NE winds across the coast. There’s a chance for a window of light variable winds at dawn but with a declining swell outlook it’s unlikely to be overly special.

Also on the cards for Friday afternoon is a new long period S’ly swell, mentioned in Monday’s notes as previously anticipated for Saturday. This swell will originate from a polar low that’s pushing underneath Tasmania and tracking towards New Zealand, expected to merge with the Tasman Low on Friday (though off the East Coast of New Zealand’s South Island). 

The models have pushed this swell forward a half-day and it now looks like the leading edge could be in to Sydney after lunch, with a chance for some 3ft sets at south facing beaches late in the day - but with dicey winds it’s hard to be confident that there’ll be anything worthwhile. 

This weekend (May 20 - 21)

The models have perked up Saturday’s south swell (arriving Friday afternoon), which I’m a little dubious on - the origin and alignment of the core fetch isn’t great, and it’s a long way from the mainland too. Our surf model has 4ft sets at south facing beaches on Saturday morning but I’m going to be a little cautious on this and peg it back to an inconsistent 3ft+. 

In any case, moderate to fresh NE winds will render most locations pretty ordinary on Saturday. We’ll see a small secondary NE swell in the mix but there initially won’t be much quality. So, don’t get too excited about Saturday right now.

Sunday looks better on the surface and although swell potential is mixed, we should see some fun waves.

Saturday’s S’ly swell will have eased throughout the day and by Sunday will be back to an inconsistent 2ft at south facing beaches, however a new long period pulse from the same polar progression is expected to build during the day and could infact exceed Saturday’s height, with size up to 3-4ft at south facing beaches. The source of this next pulse is an unfavourably aligned fetch S/SW of New Zealand but it’ll be working on the active sea state generated by the previous front (responsible for the Fri/Sat swell) and core winds are expected to reach 30-40kts, which means we could be seeing swell periods in the 14-15 second range. With just enough size in the swell this could start to activate some exposed south friendly reef breaks with bigger sets at times. 

Also in the mix on Sunday is a small peaky NE swell from Saturday’s NE winds. The fetch length is expected to be quite long (actually stretching all the way back to a broad troughy region between New Caledonia and Fiji) but with wind speeds of generally 20kts or less, there simply isn’t the fetch potential for any great size. 

Exposed beaches may pick up a few 2-3ft sets from this source on Sunday and the good news is that the trough will push offshore, allowing winds to become light and variable. So this should create favourable conditions.

I’ll refine the outlook in more detail on Friday but for now Sunday is certainly the pick of the weekend with a combo of south and north-east swells and generally favourable conditions.

Next week (May 22 onwards)

The merging systems near the South Island of New Zealand over the coming days are on target to generate some interesting swell for our region. A third polar fetch associated with this pattern looks like it’ll be the strongest of the sequence and although located right on the periphery of our swell window, should produce some solid S/SE thru’ SE groundswell for Monday.

South facing beaches should pick up 4-5ft sets from this source by the afternoon (our model has come into line nicely and is estimating 4ft sets), and conditions are looking great with light variable winds. A slow decline in size on Tuesday (starting off around the 3-5ft mark) will be accompanied by similarly favourable conditions under a NW breeze. Both days could see bigger bombs at reliable offshore reefs and other south swell magnets. So, pencil these days in the diary as they're looking unreal.

Monday and Tuesday will see slowly easing E/NE swell from Sunday’s short range pulse, and this will continue to motor along into the second half of the week thanks to a trade flow setting up camp N and NE of New Zealand early in the week. However, the latter stages of this developing system (which could end up resulting in a significant sub tropical low by mid-late week) look like they’ll be aligned away from our swell window. 

Long story short is that we’re probably looking at another ultra-extended run of distant E/NE swell through most of next week, next weekend and probably much of the following week too - but without any major size due to the vast travel distance and overall poor alignment.

See you Friday!

Comments

geoffrey's picture
geoffrey's picture
geoffrey commented Thursday, 18 May 2017 at 2:15pm

hey ben, willyweather is showing 2.1 meters of short period ene swell for tomorrow, i had a look at the surf forecast on our page here and there isnt really anything showing nor in the notes here, is it worth paying attention to?

Craig's picture
Craig's picture
Craig commented Thursday, 18 May 2017 at 2:19pm

They would be combining the easing SE swell energy and building E/NE energy incorrectly. Hence the advantage in the way we represent the data.

JackGregory's picture
JackGregory's picture
JackGregory commented Thursday, 18 May 2017 at 3:34pm

one from this morning

Yeah nah yeah nah

JackGregory's picture
JackGregory's picture
JackGregory commented Thursday, 18 May 2017 at 3:43pm

sorry ^

Yeah nah yeah nah