Sydney Hunter Illawarra Surf Forecast by Ben Matson (issued Mon 31st Jan)

Forecast Summary (tl;dr)

• Solid E'ly swell building Tues, with light winds tending N'ly
• E'ly swell peaking into Wed but with gusty S'lies developing
• Temp easing size Thurs, then rebuilding mid-range SE swell Fri/Sat/Sun, but windy with fresh SE tending E/SE breezes
• Large E/SE swell early next week for a few days with much better conditions as winds ease

Recap

Small E'ly swells padded out the weekend and this morning, with generally light morning winds. Size peaked at around 2ft each day, smaller at south facing beaches and across the northern Hunter.

This week (Feb 2 - 5)

Alright, I'm straight into the deep end this week, having not looked at the Tasman synoptics for a while (always the way, eh?).

An impressive subtropical low pressure system sliding into the Northern Tasman Sea today looks quite sublime on the charts. A broad high to the south is stretching out a lovely easterly fetch on its southern flank, and it's reasonably wide too, which should allow for a broad coverage of size the length of the East Coast.

Following a period of undersized surf early Tuesday (especially south from Sydney), wave heights will ramp up throughout the day, peaking late afternoon and plateauing into Wednesday morning before slowly easing into the afternoon, ahead of a more rapid decline in size on Thursday.

Max surf size should reach 5-6ft at most open beaches, though reliable swell magnets - a greater proportion along the South Coast (due to a slightly better fetch alignment) should see bigger sets somewhere north of 6ft to maybe 8ft at times. 

Conditions look nice and clean early Tuesday under a light offshore breeze. Note: wave heights will be smaller at this time, though starting to trend upwards, initially north from Sydney, and freshening northerlies into the afternoon shouldn't become too strong so it'll be workable all day. However southern ends will probably become wind affected so you may need to hook ito a northern corners for a late session.

A gusty southerly change is expected to rocket along the South Coast overnight, reaching the Illawarra in the early hours of Wednesday morning and Sydney just before dawn - we may see a brief window of light winds north from the Central Coast, but it won't last long. 

The timing of this change means Wednesday morning's sizeable easterly energy will focus the only rideable optoins to protected southern corners. Indeed, the strength (and width) of the change should whip up ~4ft of short range south swell to south facing beaches by late afternoon. 

A developing low along the trough line in the central Tasman Sea overnight Wednesday will redevelop a secondary S/SE fetch, slightly off-axis to Sydney's SE swell window but still enough to generate some sideband 3-5ft surf from very late Thursday into Friday (most of Thursday will be smaller, being between swell events).

However conditions look to remain blustery under the influence of a firm coastal ridge, directing fresh S/SE winds across all regions both days. 

So, there's plenty of surf on the way, but make the most of Tuesday for the best conditions.

This weekend (Feb 6 - 7)

We've got an unusual blocking pattern setting up for the weekend. 

A high pressure ridge will move in from the south, and a broad trough of low pressure extending south from the Coral Sea into the Tasman Sea - to a focal point close to the west coast of New Zealand - will receive assistance from a developing monsoon pattern across the tropical regions (probably spinning off a tropical cyclone, too).

This will result in a broad, stationary SE fetch stretching from New Zealand into the Coral Sea. Whilst not perfectly aligned for Southern NSW, we will see plenty of sideband SE energy push into our region, though local conditions look quite bumpy under a sustained fresh SE tending E/SE breezes. Early estimates are for wave heights in the 3-4ft range.

To be honest, early next week looks like seeing the best waves from this pattern so if you've got some flexibility it wouldn't be a bad idea to trade the weekend's lineups for some mid-week offerings. But, there will be waves this weekend.

Next week (Feb 8 onwards)

Currently modelling suggests we'll see a peak in the strength of the anchored SE fetch later Sunday or Monday (see below) which means a peak in SE sideband swell through Monday or Tuesday, even Wednesday.

More importantly, we are also expecting the coastal ridge to retreat at this time which should allow surface conditions to improve significantly. Monday will probably have some residual lump and wobble but Tuesday and Wednesday should be much cleaner.

Size? Easy 5-6ft+ seems quite plausible at this stage (bigger on the North Coast, and SE Qld), probably for a couple of days.

Let's take another pass on Wednesday. See you then!