Sydney Hunter Illawarra Forecast by Steve Shearer (issued Fri June 27th)

Features of the Forecast (tl;dr)

• Nice blend of S-S/SE swells Sat with morning W-SW breezes becoming light winds in the PM
• Small leftovers Sun from the S with small E/NE swell in the mix
• Long range E swell fills in Mon, persists Tues, easing Wed- long waits for sets!
• ECL or Tasman low now expected to form in trough late Mon
• Building E/NE-E swells Tues with fresh/strong SW-S/SE/SE winds developing 
• L-XL E’ly swells likely Wed/Thurs with strong SE-S/SE winds south of the low, SW north of the low
• Easing swells and improving winds Fri
• Fun leftovers into next weekend
• Check back Mon, dynamic forecast so revisions likely!

Recap

S swells built through yesterday as a Tasman Low moved offshore with size building from 3-4ft to 4-5ft (occ. 6ft set at S facing beaches) through the day under W’ly winds which shifted SW-S through the day.  A bit of lump and bump across S facing beaches this morning with offshore winds early  before swinging S’ly. Size has eased back a notch into the 3-5ft range but still offering plenty of options across the region.

Typical winters morning with offshore breezes and plenty of energy from the S-S/SE

This weekend (Jun 28-29)

No great change to the weekend f/cast. A vast area of high pressure is across the south of the continent with a Tasman Low approaching New Zealand. Over the weekend the high will slowly slide over southern NSW bringing light winds and settled conditions. In the South Pacific a very broad tradewind fetch enhanced by a tropical low is now dissipating slowly after days of swell generation. 

We’ll still see some S’ly quarter winds tomorrow morning as the high pressure ridge eses and moves north. Winds from the W through W/SW in the morning will trend light/mod S’ly before laying down to variable breezes in the a’noon. Surf-wise a very fun blend of S’ly and S/SE’ly swells to 3-4ft will trend down slowly through the a’noon.

Lovely light winds all day Sun- W-W/NW through the morning trending to light a’noon seabreezes (likely under 10kts) offer really fun all day surf conditions. S/SE-SE swells will be in the leftover stages with 2occ. 3ft sets and softening further through the day, and we’ll see a few small swell trains from the E/NE offering very inconsistent 2ft waves with a chance of bigger sets. 

Next week (Jun 30 onwards)

OK, we’re starting to get more clarity on next week’s synoptic situation which is looking increasingly dynamic so expect further revisions over the weekend or on Mon. 

The gist of it is a coastal trough extending along the NSW Coast up into SEQLD and a tropical Coral Sea trough merging with an inland upper trough fed by tropical moisture from the Arafura Sea. A dominant high sits in the Bight as a slow moving anchor to these synoptic features. 

Through Mon both the coastal and Coral Sea troughs deepen with a strong and broad E/NE-NE infeed into a developing surface low (possibly some variant of ECL) late Mon o/night into Tues. Widespread E’ly to NE’ly gales look likely to develop through the Northern Tasman extending out towards the South Pacific and then S’ly to SE’ly gales along the SW quadrant of the low Wed, tending to strong S’ly to SW’ly winds north of the low axis. 

From the low itself we are likely to see strong swells from across the compass beginning late Mon or Tues with areas south of the low axis in the line of severe weather (onshore gales and rain). North of the low will see clearer skies and offshore winds. 

That will be the main swell source next week.

Complicating that swell filled f/cast will be a significant long range E swell from the South Pacific fetch which looks to fill in Mon. 

We should see favourable lighter winds Mon -W-SW early tending to light S-S/SE breezes during the day with E’ly swells filling in from 2ft to 3ft+ through the day. That signal continues into Tues at slightly elevated levels (3-4ft).

Conditions are likely to get radical through Tues as the ECL or variant bears down onto the MNC or Hunter region with winds from the SW tending fresh to strong SE. We’re likely to see increasing E/NE swell from the developing low Tues, potentially up into the 5-6ft range. 

Wed now looks very sizey with a full fledged low off the coast, E’ly gales feeding into it and L-XL surf developing along the NSW Central and Southern coastlines - more manageable the further north you go. 

Size and winds are still in play depending on where the low ends up being positioned but current modelling suggests E’ly swells in the 8-10ft range (possibly bigger) on Wed and fresh to gale force S/SE-S winds along the NSW Coast south of the Hunter/MNC. 

Elevated wave heights are likely to continue through Thurs, easing slowly into Fri.

It may take until Fri before winds settle across temperate NSW depending on how quickly the low moves away from the coast. 

Confidence is now moderate-high for this event so batten down the hatches if you are on the south side of the low and get your plans ready for a major E swell assault next week.

We’ll come back Mon and see how it’s shaping up.

Until then, have a great weekend!