South East Queensland and Northern New South Wales Forecast by Ben Matson (issued Friday 3rd April)

Best Days: Sat: brief pulse of S'ly swell at selected south swell magnets in Northern NSW. Fun easing trade swell in SE Qld/Far Northern NSW with winds improving. Sun: generally good winds in most areas (maybe a brief N'ly in SE Qld) with a small building E'ly swell that should pulse in the afternoon (biggest on the Mid North Coast). Wed PM/Thurs: strong S'ly swell with SW tending S'ly winds, good for semi-exposed points in Northern NSW.

Recap: Plenty of trade swell, but with variable conditions - mainly fresh onshore winds, interspersed with occasional period of light variable winds (predominantly across the southern Gold Coast). Winds have been light and variable across the Mid North Coast too, but with smaller surf.

This weekend (Apr 4 - 5)

Saturday is probably the pick of the forecast period for SE Qld. 

From here on, the current trade swell is expected to slowly ease in size, and winds should also throttle back but with the same troughy caveats we’ve seen over the last few days - mainly light to moderate onshore, but with periods of variable winds in a few selected locations. At this stage it’s quite possible that variable conditions could prevail for much of the afternoon. Expect the beach breaks to hover around 2-3ft, with slightly smaller surf across the semi-exposed points.

My concern with Sunday in isn’t so much the swell, it’s that we’re expecting a low to form within a southward-tracking coastal trough off the Mid North Coast, and as a result of this, northerly winds are expected to develop across SE Qld at some point. Fortunately, we should see more of a NW tendency throughout the day which will be fine for many open beaches. However as the wind field turns counter-clockwise there may be a period of northerly winds - probably early morning - that could temporarily spoil surf conditions at exposed NE facing locations.

As for surf - the current trade swell will be much smaller by this time, but we’re looking at a small boost in E/NE swell from a restrengthening NE infeed into the developing trough. Although wind speeds aimed towards SE Qld won’t be overly strong, they will be positioned just off the coast and this should help in limiting swell decay.

At this stage I can’t see there being much more than 2-3ft from this source (probably a little smaller on the Sunshine Coast) but as long as local winds are friendly there should be some fun beach breaks throughout the day (my preference is for lunchtime through the afternoon, for the most size and best winds).

South of the border in Northern NSW, Saturday’s trade swell will be a little smaller with increasing southerly latitude, but Saturday’s local winds should generally be light and variable.

A southerly groundswell - currently advancing across the southern NSW coast, generated by a low that developed east of Tasmania yesterday - should provide inconsistent 3-4ft sets at a handful of the region’s reliable south swell magnets. And the Mid North Coast (north to about Coffs Harbour) should also pick up 2-3ft of building short range SE swell off the ridge across the southern NSW coast. 

As for local conditions, model guidance suggests we’ll see moderate to fresh SE winds develop across the Mid North Coast throughout the day as the trough takes shape but I’m not so certain that will happen. In any case expect fun lumpy beachbreaks for the most part, and aim for a morning session for the best conditions.

Sunday’s surf prospects in Northern NSW mirror that of SE Qld, but probably with a little more size potential. We’ll see further easing trade swell and SE swell off the southern ridge, but there is potential for a good pulse of E’ly swell during the day.

However, even at just 36-48 hours out from the evolution of the low-within-the-trough (expected to generate this new pulse), there are some crucial differences in the atmospheric models that could be make-or-break for a great surf session, or an average one, mainly related to how the trough develops. 

Most models - including GFS, which powers our swell model and that of every other surf forecast website - push the trough too quickly down the coast to generate any meaningful size. But the BOM’s ACCESS-R model - a high resolution model that’s been performing reasonably well at times - has a much stronger and broader indeed of NE winds into the trough overnight on Saturday (see chart to the right) - which would theoretically generate a good 3-5ft of E’ly swell across the Lower Mid North Coast (but smaller surf as you track north, due to the fetch being aimed at locations further south).

Ordinarily, the most effective forecasting technique is to remove outliers and take the line of best fit between all of the model guidance. However ACCESS-R’s projects are only just two days out - very close to genesis - and with complex troughs such as these often being a great source of surf, I really don’t want to write it off completely.

Furthermore, Sunday’s winds are looking good across most of Northern NSW - probably moderate NW across the Far North, trending lighter W’ly across the Mid North Coast. So conditions look ideal. 

So, what’s the upshot of this? I’ll fine tune these thoughts in the comments below on Saturday afternoon (and again Sunday morning) but for now I think we’ll see a combo of swells in the 3ft+ range across the Mid North Coast, with smaller surf in the Far North (2-3ft). Either way, it should be well worth your attention.

Next week (Apr 6 - 10)

Whatever E/NE swell we see on Sunday afternoon, it’ll be pretty much gone by Monday - maybe a few stray sets but nothing special, however there should be some persistent trade swell in the mix with sets around 2ft at most open beaches in SE Qld and Northern NSW.

Strengthening NW winds on Tuesday will accompany the bottom of the swell cycle (still a few inconsistent 1-2ft sets of long range trade swell, but nothing special), however a deep low is expected to form off the southern NSW overnight Tuesday and this should lead to a significant increase in southerly swell later Wednesday and into Thursday across the Northern NSW coast.

At this stage we can expect a very wide variation in wave heights between south facing beaches (6ft+) and regular open beaches (3ft) due to the swell direction. However these swells rarely favour SE Qld, so apart from the region’s handful of south facing beaches (that may pick up some 3ft+ sets), most locations will probably see small 1-2ft waves from this source. 

As for local winds, fresh SW tending S/SW then S’ly winds will accompany this southerly swell event. Then as wave heights subside from Thursday afternoon onwards, the long range synoptic charts are suggesting we’ll see a building ridge across the Coral Sea, which would probably lead to a S/SE wind field and a small short range swell across SE Qld beaches to finish the working week.

Long term (Apr 11 onwards)

Nothing significant on the cards beyond that. The Coral Sea ridge looks like it will probably influence our surf and weather through next weekend (no great surf expected at this stage), otherwise a couple of deep Southern Ocean lows tracking through our distant swell window mid-late next week should supply small long range S’ly swell through next week and into the first half of next week, for south swell magnets in Northern NSW. More on this in Monday’s update.