Sydney Hunter Illawarra Forecast by Steve Shearer (issued Wed July 2)

Features of the Forecast (tl;dr)

• Large rebuild in S-SE swells Thurs into Fri as secondary low centre slingshots around primary low
• Easing swells and improving winds Fri PM as low moves away
• Fun leftovers this weekend with light winds
• Small/tiny surf next week with offshore winds

Recap

Severe weather and building swells escalated quickly yesterday as a coastal low deepened off the Hunter and moved south to be due E of Sydney overnight. Strong to gale force (storm force gusts) SW winds developed and E’ly swells built quickly into the 6-8ft range. The low is now drifting north with the biggest swells south of Sydney (6-10ft) reflecting a narrow band of severe E’ly gales aimed at this region. Further north swells are in the 6-8ft range but likely to build again later today as the low moves north. Winds are gale force or above (60kt+ gusts at Wattamolla) and from the SW-S. A very wild and woolly day ahead with more to come. 

Very few takers at even the protected spots as large swells hammer the coast

This week (July2- Jul 4)

A vigorous coastal low is now moving N, with a secondary low centre rotating around the primary low before forming a dual-centred system, which then slowly moves away from the NSW coast later tomorrow and through Fri. Gales to severe gales from the S through SE will generate another large peak in size later today and through tomorrow from the secondary low slingshotting around the primary centre, focused on Southern/Central NSW with a much smaller payload being delivered north of the Hunter. Coastal lows or ECL’s aren’t uncommon for the NSW Coast during winter but the secondary low and related Fujiwhara effect makes this event stand out for the duration of severe weather and secondary pulse of large swell generated by this effect.

In the short run, still victory at sea tomorrow morning  with gale force SW winds and L-XL surf from the S-S/SE and smaller swell trains from the E up in the 8-10ft range with larger surf at open bommies. We will see a moderating trend in winds through the a’noon as the complex low moves away from the coast with winds easing and trending more W/SW. Size should also just soften a notch as an easing trend begins. That does open up a potential window at spots that can handle large swells from the southern quadrant. 

Conditions then ease more rapidly through Fri with early mod W-W/SW winds tending mod SW and then laying down to light/variable breezes in the a’noon as the system tracks further away from the coast and high pressure moves over northern inland NSW. Size will be on a steady ramp downwards with predominant S/SE swells to 6ft (occ. bigger set at exposed S facing breaks), dropping down to 3-5ft through the day. E’ly swells from the retreating infeed will hold some 3ft sets in the mix, becoming softer through the day.

This weekend (Jul 5-6)

Surf will continue trending down into the weekend with morning light land breezes from the W-W/NW tending to N/NE-NE breezes Sat, more NW Sun as a decaying low and front approach from the W.

Still some fun to be had Sat with size in the 3ft range at S exposed breaks, dropping through the day.

By Sun we’ll be looking at a minor blend of S/SE swell, small background E swell and minor S wrap all offering up some 2ft sets at open beaches. 

Next week (July 7 onwards)

Looks like a working week of babyfood next week as a decaying low moves into the Tasman with W-NW winds sweeping across NSW and no swell sources on tap. Tiny NE swells from the edge of winds feeding into the low are possible but we’re looking at mostly ankle-knee high surf through Mon-Thurs. 

Late in the week we’ll see an approaching front and low enter the Tasman sphere of influence and depending on the timing, we may see a late kick in new S swell Fri or into the weekend.

Models mostly indicate this system weakening as it enters the Tasman so we’ll hose down expectations for now and see how it looks Fri.

High pressure over the continent suggests more W’ly outbreaks and S swells medium term. 

Check back Fri for the latest.