Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Mon 10th Mar)

Features of the Forecast (tl;dr)

• Small, junky NE-E/NE swells Tues/Wed under an easing onshore flow
• Morning land breezes possible Wed/Thurs as pressure gradients ease
• Small bump in S swell Wed, easing from Thurs
• Slight kick in NE windswell possible Thurs PM as trough approaches
• Shallow trough brings S’ly change Fri with small swells continuing
• Not much this weekend with small swells from the S/SE and E and light winds Sat
• Increasing NE winds Sun with some NE windswell possible PM
• Action from the S next week with a trough/front Mon bringing a S’ly change and spike in S swell
• Longer period S groundswell likely later next week- check back for details but Thurs/Fri most likely
• More S-SE swell possible into next weekend if low forms in Tasman

Recap

TC Alfred supplied energy over the weekend, still a fairly solid 3-4ft on Sat (5ft sets reported), grading down into the 3ft range on Sunday. Conditions were b-grade under an onshore flow that tended E/SE-E on Sat then clocked around E through NE on Sun. Further south of Jervis Bay there were lighter winds and smaller, cleaner surf on offer. Size has eased into the 2-3ft range today, and tended more to short period windswell, likely boosting a notch into the a’noon as NE winds increase in strength. 

Small and junky surf this morning

This week (Mar 10-14)

We’ve got a large high in the Tasman, feeding moisture into the remnants of ex TC Alfred, which is blending into the monsoon trough over Northern Australia. The whole synoptic pattern on the East Coast in the wake of Alfred is a moist onshore flow which looks to persist through into the mid week. A weak front races across the lower Tasman before reinforcing high pressure slips into the Tasman to reset the flow, albeit at a weaker level. Not a great deal of swell generated by any feature this week.

In the short run we’ll see high pressure slide under Tasmania through tomorrow but the old high will be the one holding a weakening ridge down the East Coast. That will see onshore winds moderate a notch and tend more E-E/NE. No great quality expected then, and nothing much surf-wise. Short period E/NE-NE swell will hold some 2-3ft surf across open beaches and expect it to be pretty junky.

Pressure gradients back right off on Wed (and into Thurs) as the new high sits well to the south on a weakening trend. That should see clean mornings under light land breezes tending to a’noon N/NE-NE seabreezes. 

Unfortunately, not much swell to work with. The passage of the front generates some small S swell in the 2-3ft range (bigger by a notch on the Hunter) through Wed, holding into Thurs morning before easing. Otherwise, more small E’ly to E/NE’ly swells in the 2ft range to work with. 

Not much different on Thurs- small, weak E’ly swells holding in the 2ft range with a background S swell. 

Nothing much to round off the working week. A shallow, troughy S’ly change looks to push through Fri morning bringing a mod/fresh S’ly flow that quickly moderates and washes out to weak E’ly or NE’ly breezes in the a’noon. 

A small flush of short range S swell is possible but nothing much over a choppy 2ft. An off-axis fetch near New Zealand may generate some small S/SE swell but no great size is expected- just adding some more 1-2ft energy into the mix, with potential for the odd bigger wave on the Hunter and other S swell magnets. 

This weekend (Mar 15-16)

 Small weak swells continue into and over the weekend in the absence of any major swell generating systems. A massive low pressure gyre well to the south of the continent is poorly positioned with fetches aimed across the Tasman. 

We should see light winds Sat morning tending to light N-NE seabreezes and minor E’ly and SE swells to 1-2ft.

Through Sun we’ll see those N-NE winds freshen as a front and trough approach from the west- tied to the massive low centre below the continent- with some increasing NE windswell expected in the a’noon. Nothing major, but we should see surf build from 1-2ft to 2-3ft by close of play. 

Next week (Mar 17 onwards)

Action from the south is on the radar for next week, after an extended period of tropical action dies down. First cab off the rank is a frontal system and trough which looks to push across Tas later Sun into the Tasman o/night into Mon (see below) and bringing a stiff S’ly change to temperate NSW through Mon. 

We may see some NE windswell Mon morning before the change - we’ll update through the week.

Models are still divergent over the strength of the front with the more bullish GFS outlook suggesting surf building into the 5-6ft range later Mon and easing through Tues. Expect revisions on that though the week.

Further ahead and long period S groundswell from another of the deep, storm force lows passing under the continent (see below) looks to make a glancing blow later Thurs or Fri. 

We’ll pencil in S facing beaches to reach 3-4ft with outliers likely at deepwater adjacent reefs which can maximise long period S swells. 

A trough of low pressure may also form in the Tasman late next week or into the weekend with potential for S-SE swell next weekend. 

Too far off to have any confidence in specifics so check back Wed and we’ll continue to dial it in as we get closer to the event.
Seeya Wed.