Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed 23rd Mar)

Forecast Summary (tl;dr)

• Onshore winds Thurs
• Small blend of swells Fri, cleanest early before S'ly change
• Strong onshore winds Sat with an increase in short range E swell
• Short range E swell persists Sun with tricky wind outlook
• Long period S swell pulse Sun/Mon
• Uncertain outlook next week due to trough, check back Fri for latest update

Recap

Tuesday was definitely a good day with a great renewal in SE swell. Size came in a surprisingly varied range of heights considering the swell direction. Most places in the region reported good 3-4ft surf within f/cast expectations, while a few outliers rejoiced in clean 4-5ft surf with the odd 6ft bomb. Conditions were A-grade with light morning land breezes which tended to a’noon NE sea breezes. Size today has dipped back into the 2-3ft range across most of the region with a more consistent 3ft at exposed coasts. Light NW winds have already turned fresh S’ly as a trough makes it’s way north through the region. 

Sydney on the pump, Tuesday

This week (Mar23-25)

We’ve seen the best of this week, with a Tasman low which produced a few days of surf now dissipated near New Zealand.  A large area of high pressure is being displaced by a trough which is expected to linger about the North Coast of NSW through the end of the week. The trough is connected to a parent low pushing through the lower Tasman, but the combination of short period SE and longer period S swells will be marred by an onshore flow for most of this week and the weekend. 

In the short run and onshore SE winds created by a new ridge of weak high pressure filling in behind the trough will mar most of Thursday. As the high moves E those winds will tend more E to E/NE through the a’noon. We’re looking at around 2-3ft of short period SE swell and with the onshore flow it’ll be low quality stuff. 

The end of the working week also looks marginal. Short period SE swell fades out quickly leaving a weak signal in the 2ft range at exposed breaks. Another trough works it’s way north through the region, offering a slim window of lighter winds in the morning before tending SE to E/SE and freshening through the day. If you’ve got designs on a surf Fri, hit it early with low expectations.

This weekend (Mar 26-27)

No great change to the Sat wind f/cast but a solid upgrade in surf size. A high just east of Tasmania and a slow moving trough of low pressure off the Mid-North Coast (see below) direct a pretty robust onshore flow across most of temperate NSW. Expect synoptic SE to ESE winds in the 20 knot range- likely to blast right through any chance of a morning offshore breeze. That will generate a steep increase in short range ESE swell, up into the 3ft range by lunch-time, 3-5ft by close of play. So if you can get out of the wind or have a high tolerance for onshore winds there’ll be plenty of energy in the ocean. 

Sunday has a few question marks over the wind outlook. The trough area is expected to move south or reform over the Central NSW coast, offering a chance of a lighter NW-SW flow. At least one major model maintains a vigorous onshore flow, so we’ll need to temper any confidence in that wind forecast. Short period E to E/NE surf is expected to maintain surf in the 3-5ft range, likely backing off a notch during the day. Keep a go out pencilled in for Sunday. Long period S swell which we mentioned Mon from active polar fronts also looks to send some sets on Sun. Expect inconsistent sets to 3ft at S facing beaches with exposed coasts like the Hunter and S facing reefs seeing bigger 4ft surf.

Next week (Mar28 onwards)

The ongoing troughiness in the Tasman Sea is introducing a lot of variability in models from run to run so we’ll likely be revising substantially on the run as the pattern becomes resolved.

Monday should see a smaller amount of short range E swell with size in the 3ft range and lighter winds, likely NE in the a’noon. Long period S swell in the 3ft range will also be in the water, easing during the a'noon. You'll need a reliable S facing beach to see the best of this swell, so keep tabs on local winds for that opportunity.

From Tuesday things get a bit fuzzier. EC model resolves the trough with a S’ly change working up the coast and E to E/NE swell holding in the 2-3ft range. 

This S’ly pattern extends through Wed and into the end of the week as a cold front and leading edge of a strong high generate a major S’ly fetch in the Tasman Sea, extending up into the sub-tropics. That will see a couple of days of small surf before a major increase in S swell, on Thurs.

GFS has this pattern delayed substantially with a NE flow continuing through Tues and Wed and small E/NE swell in the 2-3ft range. 

The trough intensifies off Tasmania or the South Coast Thurs, with a strong though reduced in size S’ly fetch leading to a steep increase in S swell Fri. 

This trough may form another lingering low in the Tasman, with good odds for solid S to S/SE swell next weekend, first weekend of April.

Looks like an active period ahead so check back Wed for the latest update.