Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed Mar 6th)

Features of the Forecast (tl;dr)

• Pulse of S/SE swell Wed joins existing S swell with  NW-N tending NE winds
• Easing swells Thurs and a mop up day Fri
• Not much for Sat, just minor E/NE and leftover S swells
• Maybe some flukey S swell showing at S swell magnets Sat/Sun
• Building E/NE swells Sun (still small)
• E/NE swells now looking quite sizey most of next week, at least Mon-Wed, possibly building further Thurs/Fri
• May see a small low pressure system in the Tasman later next week with SE-E/SE swells
• Generally active outlook to start Autumn, so check back Fri for latest updates

Recap

Very, very solid S swells since Mon with a wide range of observed swell sizes so feel free to add your personal observations below the line. A long period pulse Mon a’noon provided surf in excess of 8ft at a few select locations. Yesterday looked under-sized (4-6ft) across areas north of Sydney with some spots south of Sydney registering 8-10ft surf in the a’noon as size rebuilt with light winds tending N-NE favouring south facing reefs. Still some 4-6ft surf around this morning, bigger 6ft+ at S swell magnets with a reinforcing S/SE swell expected to maintain or rebuild wave heights. Light NW-N winds are trending more NE through the morning and reaching fresh paces after lunch. 

A range of wave heights observed but strong lines was a constant theme

This week (Mar 6-8)

The winter-calibre low is now on the other side of New Zealand with a strong high pressure belt expected to become dominant through the medium term. We currently have a weaker cell in the Tasman, with a much stronger cell entering the Bight. This dominant high pressure belt will set up a long, broad tradewind fetch through the Coral Sea, extending at times into the Northern Tasman and South Pacific. Frontal activity to the south is shunted away from the Tasman by the downstream blocking high pattern so only minor, flukey S swells may show through the f/cast period. Otherwise, we’re looking at E’ly quadrant swells, solid in the sub-tropics, grading smaller into temperate NSW. 

In the short run and we’ll see a slow roll-off in size through the rest of the working week. Sets from the S/SE in the 3 occ. 4ft range through tomorrow, with an easing trend in play. Light NW tending N’ly winds through the morning should offer good conditions at S facing beaches before a small  trough of low pressure brings SW-S winds in the morning. Expect that in early south of Sydney (7am) with a longer window north of Sydney. The trough dissipates quickly leaving a light E-NE Seabreeze in the a’noon.

Variable winds Fri morning as a trough line lingers about the Central/Southern NSW Coast- likely offshore through most of the morning before tending to light NE seabreezes in the a’noon. It’ll be a mop-up day with leftover S/SE swells to 2-3ft at magnets, easing back to 1-2ft in the a’noon.

This weekend (Mar 9-10)

Not much change to the weekend f/cast. Light winds for Sat, tending to light NE seabreezes and only small, weak surf on tap at most beaches. Remnant S/SE energy to 1-2ft with some traces of longer period S swell from frontal energy Wed/Thurs under the continent offering up some flukey 2, possibly 3ft sets at the best S swell magnets. 

By Sun we’ll see the NE flow start to increase through the day after a light wind start. Tradewinds extending into the Northern Tasman look a little healthier so we should see some workable E/NE swell start to show in the a’noon- up into the 2ft range.

Next week (Mar 11 onwards)

Classic late Summer pattern next week with high pressure straddling New Zealand, a monsoon trough strung across Northern Australia extending into the South Pacific and a long, broad tradewind fetch between the two broadscale atmospheric features. The fetch is so broad and long that we’ll see quite an energetic E/NE swell propagate down the NSW Coast. 

High confidence we’ll see building E/NE swells Mon, up into the 3ft range and size in the 3-4ft range extending at least into mid-next week. Winds look generally light through this period with good odds we’ll see clean conditions under morning land breezes.

Model divergence then suggests lower confidence from mid next week. 

GFS suggests a retrograding low pressure centre from SE of New Caledonia into the wide open E swell window early next week with a stronger pulse possible later next week (Thurs/Fri).

The European model maintains a more bog standard tradewind fetch suggesting more of the same (3-4ft) into the end of next week.

Both models are progging the tradewind fetch to break down later next week. We may see a small low pressure system form in the Tasman during this period, the tropics are still looking active so it’s highly likely we’ll see continuing swell from the E or at least potential swell generating systems from that quadrant. S swells could also be on the menu as the downstream blocking high pattern breaks down.

A good start to Autumn.

Check back Fri for the latest.