South East Queensland and Northern NSW Surf Forecast (issued Monday 3rd February)

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thermalben started the topic in Monday, 3 Feb 2014 at 5:01pm

South East Queensland and Northern NSW Surf Forecast by Ben Matson (issued Monday 3rd February)

Best Days: Thurs/Fri/Sat: plenty of waves from a mix of sources (including some cyclone swell). Should be good waves for much of next week too.

Recap: Plenty of waves all weekend and into this morning, but conditions were pretty average for the most part with moderate to fresh E’ly winds. Sunday and Monday morning offered a brief period of S’ly winds in and around the southern Gold Coast region, but the Sunny Coast wasn’t quite as fortunate. Along the NSW North Coast, southerly winds actually developed in the Byron Bay region early Sunday morning and persisted until mid afternoon (although Saturday and today mirrored the easterly trend evident elsewhere). Gusty NE winds along the lower Mid North Coast on Saturday went variable for much of Sunday and today. So all in all, a mixed bag of East Coast mediocrity. 

This week (Feb 4-7)

Most East Coast buoys (both NSW and SE Qld) have picked up a long range easterly groundswell (Tp ~13-14sec) that originated from a deep low that formed north of New Zealand late last week, and was detailed extensively in Friday’s notes. However with generally poor winds locally this swell has largely gone to waste. 

This swell will ease in size tomorrow with no great improvement expected on the surface - mainly easterly winds will swing southerly as a gusty change tracks along the East Coast. 

The timing of the change is a little harder to pin down than usual, because of a more complex synoptic setup - we’ve got an active monsoon trough in the Coral Sea, and a strong ridge of high pressure across the southern Qld coast. A trough will also push northwards along the East Coast during Tuesday, but at the same time a series of depressions within the monsoon trough will broaden the ridge across the northern Tasman Sea, pushing its southern flank more poleward. As such there’ll be a convergence point where they all meet - and this will occur somewhere broadly across the Northern NSW Coast / SE Qld Coast, and probably some time on Tuesday afternoon

Anyway the upshot of this is that from Wednesday onwards we’re looking at a series of swell contributors for the region. As the ridge rebuilds across the southern Coral Sea, we’ll immediately see an increase in short range SE swell through Wednesday afternoon and Thursday. At the same time, one of the Coral Sea depressions (likely to be the re-intensification of ex-TC Edna, which developed for a brief period on Saturday but is currently just a Tropical Low) is modeled to track southwards into the Gold Coast’s immediate NE swell window. 

Now, TC Edna (let’s dismiss the ‘ex’ and assume it’ll redevelop) is the first well-positioned tropical cyclone to grace SE Qld’s swell window for some time. As such there are many things that are good about it, but a few things that aren’t so good.

The Good Things: 

1. TC Edna isn’t expected to waste much of its development cycle north of New Caledonia (in the Vanuatu/southern Solomons region), as seemingly happens every time a cyclone spins up in this neck of the woods. Current model progs have its main intensification occurring immediately west of New Caledonia, which is ideal.

2. From this position, TC Edna is expected to track very slowly, possibly S/SW towards the coast under a weak steering environment (another positive for swell production).

3. A strong high pressure system to the south will maintain a broad ridge across the northern Tasman Sea, which should provide a steady supply of underlying trade swell for the foreseeable future.

The Bad Things:

1. The strongest winds around TC Edna will be located on its SW flank, aimed up into the northern Coral Sea. This will keep a lid on swell heights across the SE Qld region (and probably won’t do much for the northern NSW coast, unless TC Edna tracks south of Byron).

2. There’ll be a lot of wind locally, thanks to the strong ridge - so only sheltered points will offer surfable options (some of the more exposed points could be very wind affected).

The models are having a hard time separating the individual swell trains from what’s likely to be quite a chaotic ocean state during this period. Right now I think the size estimates are pretty close (6ft+ exposed spots Thursday) but it’s suggesting the swell direction will be very south in direction early in the day, which to me is very biased towards the local windswell. Right now - and without the availability of any satellite data - I think we’ll see a broad mix of swells from the S/SE and E, with size building into the 4-6ft+ range at most open beaches Thursday (obviously the upper end of this size range at exposed wind affected spots, with smaller surf on the protected points).

Friday looks like it’ll see a similar round of swell but this is entirely contingent on how TC Edna develops. We’ll also see a SE groundswell pushing through in the afternoon, originating from a cut-off low expected to form in the lower Tasman Sea, in the wake of Tuesday’s change. It won’t offer any more size than the pre-existing S/SE and E’ly swells but still, it’s an interesting system and worth noting in the diary (and, it’ll probably be a better source of energy for the Northern NSW coast too). 

Let’s re-evaluate all of this in more detail on Wednesday.

This weekend  (Feb 8-9)

So, with three swells in the water Friday (cyclone swell from the east, short range S/SE swell from the ridge, and SE groundswell from the Tasman Low), it’s a fair assumption that there’ll be waves for the weekend. But based on existing model data is would appear that we’ll probably be on the backside of the main swells by this time, so I’d hedge my bets on a smaller round of surf on Saturday.

And here’s where things get interesting for Sunday. The monsoon trough in the Coral Sea will still be quite active around this time, and there’s a chance that we’ll see another Tropical Low - and possibly a Tropical Cyclone - developing in our swell window. At the moment the GFS model is favouring this (which, because it underpins our swell forecast system, is showing in the swell graphs) - however it’s not a view shared by all models. So, I’ll just make a note to check the data more closely on Wednesday (in any case, there's enough to work with before then!). 

Next week (Feb 10 onwards)

Next week looks unreal, with a classic trade setup developing across our mid-range swell window (north of New Zealand, south of Fiji). Regardless whether we see a low/tropical cyclone in our immediate swell window over the weekend, this broad scale, slow moving synoptic pattern points towards an additional week or so of endless easterly swell - of which there’s every likelihood that we may even see a super-charged fetch develop within this region as the active monsoon trough continues to spin off small depressions that react accordingly along the belt. 

Overall it’s shaping up for an excellent run of extended point break surf. You have been warned. Check back Wednesday for a more precise update on timings and the extended long range outlook.

mitchvg's picture
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mitchvg commented Monday, 3 Feb 2014 at 6:26pm

how are your Gulf of Carpentaria models matching the Weipa Buoy, or any reports?

thermalben's picture
thermalben's picture
thermalben commented Monday, 3 Feb 2014 at 7:13pm

Haven't looked to be honest.

mitchvg's picture
mitchvg's picture
mitchvg commented Monday, 3 Feb 2014 at 10:00pm

Well, Hsig is 2m and still climbing, vs Albatross Bay forecast of 3.6m peak during the day. Hmax has been between 3-4m though. Direction and period are on point.

OLD MATE's picture
OLD MATE's picture
OLD MATE commented Tuesday, 4 Feb 2014 at 3:57pm

Poor old W.A, S.A and Tassie don't get a report anymore?

thermalben's picture
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thermalben commented Tuesday, 4 Feb 2014 at 4:05pm

Doing 'em right now Old Mate (sorry for the delay). Craig's away for a couple of weeks so I'm squeezing his 40 hour forecasting week on to my schedule.

mozzie's picture
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mozzie commented Tuesday, 4 Feb 2014 at 7:35pm

You're doing a top job Ben! It's a rare occurrence that you've let us down; Huey does that occasionally though. The anticipation on forecasts is agonizing at times! I've been following SN since my uni days in the early 2000s & must say it's certainly been a pleasure watching the evolution. Slightly off topic I apologise but recognition is highly deserved!

The ocean is my therapist...

OLD MATE's picture
OLD MATE's picture
OLD MATE commented Tuesday, 4 Feb 2014 at 8:40pm

No worries, thanks, I agree u are doing a top job, keep up the good work...