Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 13th October)

Best Days: Late Tuesday/Wednesday: funky corners that don't usually see swell (if you're desperate). Thursday: rapidly improving surf with a steadily easing south swell and winds tending offshore. Friday: may be a small window early with light winds and small residual swells at south facing beaches.

Recap: Saturday's expected NE windswell came in well under expectations - most beaches seeing only tiny surf, with a handful of swell magnets picking up occasional 2ft sets that were rather weak. Sunday was a little smaller in size, however we have seen a much stronger NE swell today thanks to a developing NE fetch in our immediate swell window overnight Sunday. Winds did swing offshore in many locations through the early morning today but it wasn't uniform across the coast - for example Newcastle saw light northerlies until mid-morning, when fresh nor'westers kicked in whilst Bellambi (north of Wollongong) saw a similar dawn trend of light northerlies before fresh westerlies push in mid-morning. As such, conditions were OK but certainly far from perfect. This afternoon has seen a wide range of winds across the region, mainly light E'ly through NE however Bellambi is now seeing fresh NE winds as a southerly change advances along the coast.

This week (Oct 14-17 onwards)

The surf outlook is very dynamic for the next few days. An East Coast Low is modelled to form off the South Coast overnight, and will intensify through Tuesday, driving gale to storm force S/SE winds into much of the southern NSW coast. 

Interestingly, Tuesday will probably start off considerably undersized, compared to what's due over the coming 24 hours. The southerly change currently moving up the coast is not directly related to the East Coast Low (which will be developing further south) - a secondary 'change' of sorts is due through the early part of Tuesday morning as the ECL winds up, but there's actually a chance for a brief period of SW winds close to dawn (mainly north of Sydney). 

Nevertheless, we're likely to see 2-3ft sets at south facing beaches for the dawn patrol and a reasonable level of residual NE windswell from today as well (2-3ft open beaches, but fading) at NE facing beaches. It'll be well worth a quick dawny squizz at those open beaches picking up the NE swell across the Northern Beaches and southern Hunter coast, before things get out of control (winds, waves and weather).

As the morning wears on and southerly winds strengthen to storm force into the afternoon, we'll see a rapid increase in short range S/SE swell that should top 10ft+ at south facing beaches by the end of the day, possibly more. However even protected southern corners will cop a hammering - under these conditions it's really hard to get excited about surfing. If you're desperate, there'll possibly be some small waves in funky corners that don't usually see surf, but you will have to be keen and competent.

This swell is expected to peak in the early hours of Wednesday morning. We should see upwards of 10-12ft at south facing beaches early on, but local winds are modelled to remain gale to storm force S'ly through this period.

However, the low is also expected to move away from the coast during the day, and as this happens we'll see wind speeds ease slowly - and possibly swing south-west. In fact, there's been similar synoptic events in the past where microscale/mesoscale low pressure systems have formed within the broader parent system, delivering short periods of different wind patterns. I'm not particularly confident that this will happen, but in such a dynamic system it can't be ruled out. If it does occur, then we'll see conditions rapidly improving across the region. Regardless, protected southern corners will probably be your only real option at any point on Wednesday. Surf size should then ease reasonably steadily into the afternoon.

Thursday is a much safer bet for a vast improvement in conditions, along with a rapid moderation in surf size. South facing beaches are still likely to be somewhere around 4-6ft early morning (and continuing to fall during the day) but winds should be back around to a light W'ly as the low retreats to the central Tasman Sea.

Beaches not open to the south will be much smaller - swell direction will tend more southerly if anything by Thursday, thanks to a realignment of the low during Wednesday - but it'll be far more manageable. The main concern is how much damage will be done to the banks and beaches, as we haven't see a storm system like this for a while. A common outcome is the formation of an offshore storm bar, with wide, deep gutters separating the usual surf zone and the shoreline. Let's wait and see what happens.

Friday then has a moderate to fresh southerly change on the cards. Surf wise, we're looking at residual swells in the 2-3ft range from a couple of sources out of the southern quadrant, but at this stage there may be only a brief window of good winds early morning. I'll have more on that in Wednesday's update.

This weekend (Oct 18-19)

Nothing major on the cards for the weekend at this stage. 

A small southerly swell is expected to trail Friday's change and that'll probably be the primary source of energy, peaking on Saturday. Winds are expected to be light and variable with sea breezes. 

A small E/NE swell is also expected to gradually push through over the weekend, generated by a slowly developing E'ly fetch north of New Zealand during the second half of this week - however no great size is expected from it. Early light winds and freshening NE sea breezes will probably pad out Sunday.

All in all, a good weekend for the swell magnets at this stage. 

Long term (Oct 20 onwards)

No major patterns on the long term charts at this stage. Freshening NE winds on Sunday afternoon may kick up a short range NE windswell for Monday with possibly some intensification (and consequently bigger surf) through Tuesday - but aside from that it's all daily standard for this time of year. Let's see how the numbers are stacking up on Wednesday.