South East Queensland and Northern New South Wales Forecast by Ben Matson (issued Monday 6th April)

Best Days: Later Thurs/Fri/Sat/Sun: strong S'ly swell with good winds for the points (size peaking Fri, easing Sat onwards). Only small in SE Qld due to the swell direction but there'll be a few waves about.

Recap: A great Easter of waves across most open beaches with a pulse range of E/NE and E/SE swells (plus a S’ly swell across exposed south facing beaches on Saturday), and generally favourable conditions. Sunday and Monday ended up being a foot bigger than forecast, which is surprising as the primary fetch within the southward tracking trough/low was aimed at points south of the North Coast (southern NSW saw a similar peak in size).

This week (Apr 7 - 10)

Small leftover/residual E’ly swell is expected for the next few days with a gradual easing trend. Winds should be NW on Tuesday but a westerly change is expected on Wednesday as wave heights bottom out. There’ll be small peaky waves at exposed beaches but nothing of any great substance is expected.

The rest of the week looks very dynamic on the synoptic front. As discussed last week, we’re expecting a deep cut off low to form rapidly off the South Coast early Wednesday morning, and as this happens, gale to storm force southerly winds will develop parallel to the southern NSW coast. Very large waves are expected to impact this region from late Wednesday through Thursday.

The models have upgraded this system a little since Friday’s notes were prepared, but there’s a lot of complexity surrounding its influence for Northern NSW and (especially) SE Qld.

In particular, the strongest winds will initially develop too close to the southern NSW coast - inside the Hunter curve - to be of any great benefit to anywhere north of Seal Rocks (not that local winds will be favourable for exposed beaches anyway). It won’t be until the low pushes east, away from the mainland (early hours of Thurs morning), that it’ll fall into the swell window for Northern NSW - but by then wind speeds are expected to have throttled back a little. Although, the size and coverage of the fetch will be considerable, occupying the western third of the Tasman Sea.

So, what this means is that we’re looking at a strong and sizeable south swell building through Thursday across Northern NSW, but it may not reach the Far North Coast until overnight. Wave heights should reach 6ft to maybe 8ft at exposed south facing beaches by the end of the day (south of about Yamba or Ballina) but winds will be gusty from the south. Due to the southerly swell direction, wave heights will be much smaller at locations with less southerly exposure (generally 4ft+ open beaches, 2ft sheltered southern corners).

This swell event will then peak across the entire coast - including SE Qld - on Friday. Fresh and gusty SW tending S’ly winds will limit the best conditions to protected points however as per usual we’ll see a wide range in size across the coast, anywhere from 6-8ft at exposed south facing beaches in Northern NSW, to 3-5ft across semi-exposed points, and 2ft inside sheltered southern corners. 

North of the border though, SE Qld will struggle to pull in any major size due to the southerly swell direction - most beaches will probably see inconsistent 1-2ft waves, up to 2-3ft at the outer sections of various semi-exposed points, and possibly 4ft+ at the region's handful of exposed south swell magnets (although fresh S/SE winds will limit quality at these spots anyway).

However, all of these particulars will require further reevaluation on Wednesday once we’ve got a little more data in on the developing low. I'll update then with better confidence on size and timing.

This weekend (Apr 11 - 12)

The low generating this large mid-late week swell will move slowly eastward throughout the forecast period, and a slow moving high west of Tasmania will maintain a broad southerly fetch through the Tasman Sea right up into the weekend.

This means we’re looking at a slowly abating S/SE swell through the weekend with accompanying winds from the southern quadrant (early SW in some areas, tending S’ly then S/SE during the days). Such a scenario will favour semi-exposed points for the best waves although Saturday looks like it’ll have more size than Sunday. And, due to the swell source and direction, SE Qld will remain only small.

I’ll firm up the specifics in more detail on Wednesday.

Next week (Apr 13 onwards)

The latest model guidance is in general agreement about an amplifying Long Wave Trough through the southern Tasman Sea later in the weekend, which suggests we’ll see an excellent, and possibly sizeable southerly groundswell develop across the East Coast early next week (current ETA late around Tuesday in Northern NSW). 

It’s too early to have any level of confidence but if things play out as currently expected - with the storm track positioned well to the east of the Australian continent - there’s a fair chance that local winds won’t be greatly affected by it (read: local conditions could be very good). So, if large long period south swells are your thing, it’s worth pencilling in the first half of next week for some solid action (note: these swells don’t often favour SE Qld so you’ll need to consider your options south of the border for the biggest and best waves). More on this in Wednesday’s update.