Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Mon Feb 5th)

Features of the Forecast (tl;dr)

• Sizey NE windswell Tues AM with variable winds possible before a robust S’ly change
• S pulse Mon PM, easing Tues- flukey but showing strongly at some S swell magnets due to long periods
• Plenty of short range S-SE swell developing late Tues, extending into Wed and easing slowly through Thurs/Fri
• S-SE flow extends Tues-Fri, slowly easing Thurs/Fri
• Flukey S/SE groundswell Thurs/Fri
• Tradewind swells likely to filter down to temperate NSW later next week
• Small mixed bag of S swells Sat with S-SE winds 
• S’ly groundswell Sun with SE winds
• More E’ly quadrant tradewind swell next week
• S’ly groundswell likely late next week

Recap

Very strong S’ly groundswell with a lot of size and power filled in Sat with 6ft+ sets by mid morning and deepwater S facing bommies showing sets in the 10-12ft range. Light winds tended NE in the a’noon. Size dropped quickly through Sun with a few 4ft sets early, dropping back to 2-3ft through the day, joined by some NE windswell in the a’noon. Today is seeing a peaky mix of NE windswell and small S leftovers to 2-3ft with some sneaky new S groundswell expected to fill into S facing beaches in the a’noon under mod/fresh N tending NE winds. An active week is ahead although with plenty of S’ly wind to negotiate. Read on for details.

Getting very solid by late morning Sat

This week (Feb 5-9)

We’ve got a complex pattern playing out at the moment with an inland trough/low approaching the coast, expected to bring a major S-S/SE change in conjunction with a new high moving in from the Bight. A semi-stationary area of low pressure in the Coral Sea is anchoring a broad trade-wind flow with an extended tradeswell event ahead. To the south, a severe gale to storm force fetch off the ice shelf from a retrograding low under the South Island sends a rare S/SE groundswell up the Pipe, with another strong front/low late this week into the weekend expected to generate another pulse of S’ly groundswell over the weekend.

In the short run we’re looking at a blend of chunky NE windswell and leftover S groundswell through tomorrow. NE windswell should peak in the morning to 3-4ft with some S sets to 2-3ft, both swell sources easing during the day. A S’ly change from the trough looks to be in from first light south of Sydney, moving north of the harbour by mid-morning with an early window of NW winds before the change. Latest runs show a rapid deepening of the trough with S’ly winds exceeding 30kts through the a’noon, likely whipping up a late spike in new short range S swell.

That S swell will be solid on Wed with mod/fresh S’ly winds, easing a notch in the a’noon and tending S/SE. Expect a raw S swell to 4-5ft through the morning, likely with a slight easing trend in the a’noon. Smaller waves on offer at sheltered breaks where some minor E/NE swell filtering down from the tradewind fetch will see some 2ft sets mixed in with the S swell wrap.

We’ll still have a S/SE flow on Thurs as the angled trough sits in the Tasman, we may even see it intensify into a small low. That would see an upgrade in size from the SE. We’ll pencil in 3-4ft surf from the SE on Thurs and finesse on Wed. The curveball on Thurs is some rare S/SE groundswell from the current ice shelf fetch which should offer some inconsistent 3ft sets into the mix. Local winds will make it hard to utilise the maximum size of the swell. Also in the mix will be E/NE swell from the sub-tropics offering up mostly 2 occ. 3ft sets.

We should see that S’ly flow backing right down for Fri morning with morning land breezes likely. Another mixed bag with S/SE groundswell to 3 occ. 4ft , SE swell and E/NE swell offering up 2-3ft surf. Potentially with some nice a-frames if the wind plays ball.

This weekend (Feb 10-11)

Looks like the S’ly flow kicks again Sat as a new high cell approaches from the Bight and the trough of low pressure which has been sitting in the Tasman focusses the new high pressure ridge. To the south a strong front is expected to be traversing the lower Tasman. If you can work around the mod/fresh S tending SE winds there will be some swell to play with. S/SE groundswell still throws up some 3ft sets along with short range SE swell to 3ft. Expect to sacrifice some of that size to get out of the wind though.

S’ly groundswell from the frontal passage in the Tasman joins the party on Sun, mixed with the shorter period S/SE-SE swell trains. That should see 3-4ft of S swell, bigger 4-5ft on the Hunter quality still affected by S/SE-SE winds, which should lay down through the day although it’s it’s unlikely to clean up at S facing beaches. If you can deal with some lump and bump there will be plenty of swell energy in the water.  We may see a tendency for an earlier NE flow if the high moves out into the Tasman quicker than currently modelled, so check back Wed for that.

Next week (Feb12 onwards)

A bit of model divergence for next week but the basic gist of the pattern is twin high pressure cells straddling the North Island with a healthy trade-flow rebuilding in the Southern Coral , Northern Tasman Seas and extending into the South Pacific. 

We should see easing S swell to start next week, mixed in with E’ly swell from this trade-wind flow.

We may see an increase in that E’ly swell by mid next week, depending on the strength of the flow and the fate of a depression located near New Caledonia.
ECMWF suggests the low will drift back into the Coral Sea bringing an increased E swell signal for most of the East Coast while GFS has the low dissipating or drifting towards Vanuatu with a small E’ly tradewind signal.

Further ahead we should see another moderate/strong frontal system moves into the Southern swell window mid next week bringing another pulse of S’ly groundswell late next week.

Let’s see how it looks on Wed.