Large south swell bearing down

Ben Matson picture
Ben Matson (thermalben)

Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 13th May)

Best Days: Thurs/Fri/Sat: very large S'ly swell, biggest Friday but windy at times. Sun: light winds and easing S'ly swell. Mon/Tues/Wed: small long period S'ly swell at exposed beaches.

Recap: Tuesday’s south swell generally came in just under expectations, although my observations on the Northern Beaches (via the daily surf report) showed clean 3-4ft sets early-mid morning, with bigger waves across the Hunter. There was a small increase between dawn and mid-morning across most regions so perhaps the swell suffered from a late arrival. Either way, conditions were clean under a light offshore breeze and wave heights fell steadily overnight, leaving us with 1.5ft waves at exposed beaches this morning (2-3ft in the Hunter).  We’re now seeing a small increase in new S’ly swell with 2-3ft sets showing at south facing beaches. A further increase is expected as the afternoon progresses however winds have gone S/SW at some locations, rendering exposed beaches bumpy. 

This week (May 14- 15)

Lots of south swell for the next few days, with no real change to the outlook for the rest of the week. 

A front pushing up the coast now will generate a mid-range 3-4ft S’ly swell for Thursday morning, but it’ll be quickly overtaken by a combination of long range S’ly swell from a low south of the Tasman Sea this morning,  and another stronger secondary front entering the lower Tasman Sea in the early hours of Thursday. This should build wave heights up into the 6-8ft+ range at south facing beaches by the end of the day. Expect much smaller surf at remaining beaches (4-5ft) and inside southern corners (2ft+) as the swell builds to a peak. As per usual it’ll be bigger in the Hunter but very wind affected under this airstream.

As for conditions, we should see early W/SW winds across the coast but they’ll veer SW mid-late morning and then fresh, gusty S/SW through the afternoon. So your best bet will be to sniff around for somewhere protected as these winds will cause a lot of problems at exposed spots.

On Friday, we’re looking at a slightly bigger pulse as a stronger S’ly groundswell pushes through, generated by a deeper low positioned within the middle of the overall pattern (in the central Tasman). This is in fact the merger of two separate fetches mentioned in Wednesday’s notes (related to Saturday’s expected pulse) and will provide the peak size from this entire event.  

South facing beaches should see strong 8ft+ waves for most of the day, and with the swell direction swinging marginally to the east of south, there should be a slightly greater spread of size across the coast - 5-6ft surf at most open beaches, and 3-4ft inside protected southern corners. The exposed Hunter coast is looking at apeak in size closer to 10ft+. Again, fresh to strong S/SW winds will create difficult conditions away from the sheltered southern ends but we may see a brief period of W/SW thru’ SW winds across a few select locations (i.e. Northern Beaches). 

Wave heights may ease slightly into the afternoon but it’ll still be very large and unruly across the coast.

This weekend (May 16 - 17)

On Wednesday I mentioned a final pulse of south swell for Saturday, however (as discussed above) it’s been consolidated into Friday’s peak. That being said, we’re still looking at very big waves through Saturday morning, and the good news is that local winds are expected to throttle back as a high pressure system pushes in from the west.

We will still be under some form of southerly airstream on Saturday but it’ll be a lot weaker than Friday, and local winds should be SW across most regions early morning (tending moderate S’ly, then maybe SE through the afternoon). South facing beaches should manage 5-6ft+ surf early, with a steady easing trend taking place throughout the day. However, wave heights will be much smaller at beaches with less southerly exposure. The Hunter should see some bigger bombs in the morning.

Sunday will see the downward trend continue (3-5ft south facing beaches, smaller elsewhere, easing steadily) and early light winds should make for clean conditions at most beaches.

Next week (May 18 onwards)

There are no major weather systems expected within the Tasman Sea next week, so our surf prospects will hinge around the migration of several polar lows through the Southern Ocean. Each system looks pretty good on the synoptic chart, however they will be positioned quite a fair distance from us (which will keep surf potential down) and I’m also a little worries about the overall storm track (more zonal than preferable, and a little too fast as well).

Nevertheless, this is where our attention will be focused on, beyond the weekend. Two small pulses of south swell are due on Monday and Tuesday, but Wednesday is on track for a small but very long period S’ly swell (originating from the strongest of the polar lows) that could light up exposed beaches with some very fun waves. More on this in Friday’s update. 


thermalben's picture
thermalben's picture
thermalben Wednesday, 13 May 2015 at 5:54pm

Well, there's a wide spread of south swell!