Sydney, Hunter and Illawarra Surf Forecast by Guy Dixon (issued Friday 29th April)

Best Days: Each morning

Recap: 

Open beaches have been picking up good easterly trade energy over the past couple of days, with peaks in the 2-3ft range. 

Winds have been light offshore each morning preceding a mid-late morning seabreeze, but today has been lacking in the quality department as winds never swung properly offshore. Instead, light northerly breezes persisted throughout the night, adding an element of bump and wobble to the mix.

This weekend (Saturday 30th - Sunday 1st):

As discussed in previous notes, a strong  blocking ridge has been inhabiting the Tasman Sea in the over the past few days, with frontal activity forced to be diverted south with poor alignment to the NSW coast.

This high has been slowly migrating further east and will eventually be bumped off its perch by a series of front over the weekend and into early next week.

But in the meantime, broad easterly trade fetches along the northern quadrants of this ridge have been generating trade-swell which should continue to provide through the weekend.

Open beaches can expect to hold in the 2ft range on Saturday, with a slight period pulse and increase in size on Sunday where the odd 3ft set could fill in. A small amount of northeasterly windswell is also likely to be in the water on Saturday morning as a result of a local fetch increasing today, although only modest with peaks in the 2ft+ range.

We are in for a light north/northwesterly airflow on Saturday morning, improving with time and becoming more favourable before an afternoon northeasterly seabreeze kicks in. Sunday’s early northwesterly breeze look much more established, with only the outside chance of swinging northerly or north/northeasterly throughout the day. Conditions should remain generally clean for most of the day.

Next week (Monday 2nd onward):

As a front moves to the south from Saturday night into Sunday, a small cut-off low looks to develop to the southeast of Tasmania during Sunday morning, moving in a southeasterly direction fairly rapidly.

While the fetches along the northwestern quadrant of this system are small, the intensity of the 45kt core winds should provide a small southerly swell for south facing beaches which have been having a fairly quiet all week.

Two pulses of southerly swell are due, the first filling in during the middle of the day/afternoon Monday to 2-3ft across south facing beaches, with a secondary pulse overnight, easing from 2ft Tuesday morning.

A better source of swell will be the lingering easterly pulse from Sunday, with reinforcing energy keeping options in the 2-3ft range at open beaches on Monday, a touch smaller on Tuesday.

Light westerly breezes are on the cards on Monday before easing and tending onshore, while Tuesday is more likely to be clean all day under persistent west/northwesterly breezes.

A pair of strong frontal progressions look to sweep over the nation’s southeast into Tuesday and Wednesday, but still with very poor alignment for the NSW coast. The phase of the long wave trough is much more favourable for South Australia and Victoria at the moment, so any frontal progressions are on their southward motion before entering our swell window. 

Pre-frontal fetches will be strong northwesterly, with low latitude westerly trailing fetches not having presenting much more promise. Sideband energy is our best bet for the late week, but only the most exposed south facing magnets have the potential of picking up background refracted energy.

Instead, cast your eyes to the eastern swell window yet again where the easterly trade flow looks to increase and tend more east/northeasterly throughout the early stages of next week as a result of an increasing pressure gradient around a deepening easterly dip over the Tasman.

This increased activity looks to provide an increase in trade-swell, potentially building to 3ft by Friday afternoon, larger into the weekend.

More to come next week.