Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 1st February)

Features of the Forecast (tl;dr)

• Short range, wind affected S'ly swells building Tues, peaking Wed, easing rapidly through Thurs
• Building trade swell Wed/Thurs
• Strong, sizeable swell from TC Lucas building Friday, peaking Sat, easing Sunday
• Stacks of swell into the long term too

Recap: Saturday was a little wobbly to begin with, but the NE breeze eased through the day to become light into the afternoon, and sets managed somewhere between 3ft and 5ft out of the E/NE. Sunday saw easing size to 3ft but with fresh S’ly winds. A further easing to 2-3ft this morning was accompanied with light S’ly winds, wave heights are now down to 2ft. 

Next week (Feb 2 - 5)

There are more curveballs in this week’s synoptics than a major league baseball team.

First up  remember those two lows in the Tasman Sea, discussed early last week but dismissed in Friday’s notes? Well, the second one is still expected to form west of Tasmania around Thursday (outside of our swell window), but the first will now crop up off the Southern NSW coast on Tuesday, peaking in strength overnight before abating and slipping to the south-west on Wednesday.

The low won’t be terribly large nor powerful but it’ll have a reasonable southerly fetch on its western flank, which will generate building S’ly swells through Tuesday, peaking Wednesday with sets around 4-5ft at south facing beaches, before easing into the afternoon. It’ll be all gone by Thursday. Expect smaller surf at beaches not open to the south.

The close proximity of the low to the mainland means we’ll see fresh southerly winds accompanying the building swell. Overnight N/NE winds (tonight) ahead of the change will generate some peaky NE windswell on top of a small underlying E/NE trade swell, so exposed beaches should pick up 2-3ft sets, though the change is due into the Illawarra several hours before dawn, and Sydney around dawn (give or take), so expect blustery conditions from early on. Though, locations between Sydney and Newcastle may see an hour or two of favourable winds for the early session. 

Local winds will remain fresh S’ly into Wednesday morning - there’s a low chance for early pockets of SW winds, to just one or two locations such as the Northern Beaches - however we should see a gradual easing into the afternoon as the low throttles back.

Now, while all of this is going on, some major developments will be happening to our north.

As discussed over the last week, we’ve got an active MJO phase across the region, and a strong high pressure ridge across New Zealand is cradling a conveyor belt of tropical lows, including one remnant and two existing tropical cyclones (TC Bina, TC Lucas, TC Ana - see recent chart from JTWC below). It’s a very dynamic pattern, and we’re still on track for a sustained run of E/NE groundswell. 

Of the two active tropical cyclones, TC Ana is furtherest away, contained in the monsoon trough and is tracking E/SE towards the South Pacific. Although its path is not usually viewed as being favourable for East Coast swell development, the supporting ridge to the south was active all weekend and E/SE thru’ SE gales will continue into tomorrow, so we’ll see a healthy spread of E/NE swell fill in across our region. 

TC Lucas has much more potential.

It’s currently west of Vanuatu, inside the Coral Sea, and will pass over New Caledonia early Wednesday, thereafter tracking very slowly south-west towards the NSW coast - though probably dissipating before it has a chnce to influence local winds to any major degree (that's a good thing).

Although wind speeds won’t be amazingly strong through TC Lucas' latter developments in the northern Tasman Sea, it’ll be working on the active sea state generated by TC Ana and thus will greatly enhance projected wave heights across the region. We’ll see the most size across Northern NSW and SE Qld but Southern NSW should pick up plenty of size. 

As for size: calculating the exact phase of each overlapping swell train is a little tricky, so let’s pain in broad brushstrokes. 

Our model guidance has an unusual low point on Thursday which doesn’t quite resolve with my manual calculations. Sure, the south swell from Tues/Wed will be fading rapidly by this time but we should be seeing decent E/NE swell from the supporting ridge below TC Ana by this stage. It is fair to acknowledge that the fetch from this ridge has angled a little way out of our swell window since Friday (thanks to the new developments of TC Lucas) but I feel Thursday should be worth at least 3-4ft at most open beaches. Winds look to be light under a weak pressure pattern so conditions should be clean. 

Friday is where we’ll start to see the bulk size from TC Lucas start to fill in, ahead of a peak in size on Saturday. Wave heights should build to 4-6ft at NE friendly locations by the end of the day, though there is some concern that the developing low west of Tasmania on Thursday will encompass a broad inland trough, leading to a freshening NE breeze across Southern NSW. 

Let’s firm up the specifics in Wednesday’s notes. But, there'll be plenty of surf to pick and choose from. 

This weekend (Feb 6 - 7)

There will not be any shortage of surf this weekend.

TC Lucas is expected to maintain strength in the Central/Northern Tasman Sea into Friday afternoon (see below), which means we’ll see a broad peak holding into Saturday, probably pushing 6ft+ at exposed coasts. We could see more size than this - not so much because of wind strength, but the sustained nature of the fetch, and the fully developed sea state I discussed on Friday - though I really want to see another couple of model runs before committing. 

There’s still a (modeled) threat of NE winds locally, however Sunday should see much better conditions as the trough pushes offshore, allowing winds to become light. 

Wave heights will be easing through Sunday but early morning is still expected to see 4-6ft sets at exposed beaches. So, that’s the pick of the forecast period right here and now. 

Next week (Feb 8 onwards)

The parent low to the trough responsible for Sunday’s improving winds should pass south of Tasmania over the weekend, allowing southerly winds on its western flank to generate fresh new S’ly swell for early next week (initially a local windswell on Monday, then a better groundswell Tues/Wed).

At the same time, more tropical cyclone activity is pegged for our NE swell window, with a new system forming in the Coral Sea on Sunday - initially outside of our swell window - plus another system out near Fiji.

Their swell potential is as yet unclear. However, it looks like our eastern swell window still has a ways to go. 

Gotta say, it’s a pretty exciting time to be looking for waves along the East Coast. Hope you can get amongst it!

 See you Wednesday.