South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Friday 9th February)

Best Days: Most days will have fun waves, though Sun has a risk of N'lies (in Northern NSW) so do Mon-Wed in SE Qld. Late Thurs onwards looks like seeing the start of a large long period E'ly cyclone swell, that could persist into the start of the new week. 

Recap: Easing S’ly swells across Northern NSW Thursday gave way to a small rise in E’ly swell throughout the afternoon that’s persisted into Friday. Winds have been mainly light and variable with sea breezes. 

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This weekend (Feb 10-11)

Just a small downgrade for the weekend’s expected E’ly swell, generated by a westward-tracking E’ly trough north of New Zealand over the last few days. The fetch came in slightly under model guidance, and whilst it’s quite long, it’s not especially broad so I’m just hedging my bets a little.

Northern NSW will see the most size due to a more favourable coastal alignment with the swell direction. We’re looking at surf size building from 3ft+ to 3-4ft+ from Saturday thru’ Sunday, and conditions are looking best Saturday ahead of a developing northerly airstream on Sunday. Fortunately, the models have eased back the strength of these winds so we’re likely to see a few locations pick up an early NW flow. Saturday will see early light winds and afternoon sea breezes. 

Across SE Qld, this swell will be a little smaller, building from 2-3ft tp 3ft+ across most open beaches and outer points, with a few bigger sets across the northern ends on Sunday.  

Saturday is by far the best day with light variable winds and sea breezes; Sunday’s northerly won’t get too strong here but even 10kts is enough to spoil the points. However, we should see a reasonable period of early NW winds that’ll favour the beach breaks nicely. 

Also in the water on Saturday will be a small long period S/SE swell, generated by a polar low south of New Zealand earlier in the week. It reached Sydney this afternoon with peak swell periods around 15 seconds, and should provide some useful (though not especially large) surf across Northern NSW. This source will ease into Sunday as the E’ly swell reaches a peak.

Next week (Feb 12 onwards)

Early next week looks a little tricky.

A weak trough will slide up the Southern NSW coast on Sunday, pushing off the coast and possibly forming a small low into Monday, though without any appreciable strength (and thus with a low swell generating capacity).  

The presence of this low should disrupt Sunday’s regional northerly flow, though not perhaps up the entire coast - maybe as far as the Tweed Coast, possibly the Gold Coast at a stretch.

We’ll see a stagnated synoptic pattern for a few days, so in short: there’s a risk of northerlies from Monday to Wednesday across SE Qld, but as you head south into Northern NSW it’s likely to be much weaker, and may not eventuate at all (particularly in the south). Don't completely discount the surf in SE Qld though, these unstable patterns often see pockets of variable conditions in and around thundery periods; it's not a deep, established northerly flow so there'll be a few workable windows of opportunity.

A couple of minor swell sources may spin up at this time - the aforementioned low off Southern NSW on Monday (if anything, generating a minor SE swell for the lower Mid North Coast on Tuesday), we may also see some small peaky N’ly windswell across the Gold and Tweed Coasts early next week from a persistent though only moderate fetch off the SE Qld coast, and there's also a source of small mid-range south swell on Tuesday, from a secondary low further south (SE of Tasmania) on Sunday though no great size is expected from this either.

Monday should also see an appreciable level of easing E’ly swell from the weekend too. However as mentioned, northerly winds will cause a few problems in the north. 

And last of the minor swell sources: a vigorous front exiting Bass Strait on Wednesday may generate a minor S’ly swell for Northern NSW on Thursday afternoon, though again it’s expected to be pretty small and will also be flukey in which beaches it targets. Further strong fronts to the south of Tasmania on Thursday and Friday will generate small southerly groundswells for next weekend too, though at this stage they look like being pretty steep in direction so will only favour reliable south swell magnets south of Byron.

Now that’s all out of the way, let’s take a look at the real juicy stuff throughout the forecast period.

As has been discussed for the last few weeks, an active monsoon trough through the Tropical South Pacific is spinning off a series of tropical lows, and we’re now at a point where confidence is increasing significantly as to how this will all play out.

It now looks like we’ll see at least one severe Tropical Cyclone develop east of Fiji over the coming days, tracking eastwards before recurving to the south, then east before tracking straight through the South-western Pacific enroute to the Tasman Sea. 

Wind speeds within this system are expected to be very strong, and its westward track will help to enhance swell size and strength. At this stage the models have the leading edge into the East Coast on Thursday with peak swell periods around 16 seconds in SE Qld, 17 seconds across the Mid North Coast, and up to 18 seconds in Southern NSW (this is as high as swell periods get from this quadrant). 

Depending on how the cyclone behaves - i.e. just how far it tracks through the Tasman Sea - we’re looking at either moderate to large, or possible very large E’ly swells developing across our region from as early as Thursday afternoon, building into Friday and persisting through next weekend, holding into Monday before easing from Tuesday onwards. 

How big? Its way too early to put a figure on it, but I wouldn’t be surprised if the peak of the event pushes north of 8ft+ at its peak, sometime over the weekend. And there’s a very good chance that this could be significantly upgraded too.. anything is possible from this swell, to be honest - they're rare events, and we're still quite some time away in forecast model land. 

But exactly where the swell will be focused will take more than a few days to pin down.. tropical cyclones (especially severe systems) are notoriously flukey at even a few days advance notice and there’s a long way to go until confidence can be at a level worth planning your diary around.

So, the take home message is that we’re looking at a large, long lived, long period swell event from late Thursday onwards. 

Time to start doing some cardio, y’reckon?