Sydney Hunter Illawarra Surf Forecast by Ben Matson (issued Mon 17th Feb)

Features of the Forecast (tl;dr)

• Solid sideband S/SE and E/NE swell combo peaking Tues, easing Wed
• Light winds and seabreezes Tues and prob Wed too
• Fun top up of S'ly swell Thurs though a S'ly change will push through at some point
• Leftover S'ly swell Fri/Sat with early light winds
• Building NE swell Sat PM and Sun though with freshening NE winds
• Interesting tropical devlopments for the long term

Recap

E/NE swells built across the Southern NSW coast on Saturday though the morning started out undersized, with sets around 2-3ft. A pre-dawn southerly change (nosing into the Hunter shortly after sunrise) didn’t exhibit much strength through the day so conditions remained quite OK. Sunday offered a mix of south and E/NE swell around 3-4ft, that built more during the day as southerly winds freshened, with size eventually reaching a wobbly 4-6ft at south facing beaches. Wave heights held in at this size range this morning before easing into the afternoon, though we are still expecting a late pulse of longer period S/SE groundswell. Winds have continued to be a bit of a problem though southern ends are offering cleaner conditions. 

This week (Feb 18 - 21)

There's no shortage of swell on tap for this week, though I am going to marginally pull back my expectations from the Tasman Low that developed on Sunday.

To clarify further, I’m not revising my size estimates as such, it’s just that the fetch around the low - which should be pushing 50kts as we speak - is aimed away from the NSW coast (see below) so we’re looking at sideband energy glancing the coast later today and into Tuesday, which will probably only benefit a small number of reliable south swell magnets for the most size. And to be even more specific, locations further north stand a better chance than those to the south. 

So, whilst there'll be plenty of hits tomorrow, it's likely we'll see quite a few misses too.

Peak surf size should still push 5-6ft at those swell magnets - maybe even a few bigger bombs across one or two reliable bombies - but most beaches will come in smaller (say, 3-5ft). Fortunately, there will also be a decent though very inconsistent E/NE groundswell in the water (generated by a tropical low north of New Zealand over the weekend) and this will provide a much more efficient spread of size across the coast, anywhere from 3ft to 5ft. 

Even better, local winds are looking great with early offshores and weak afternoon sea breezes. 

Easing swells are expected from both sources on Wednesday with generally light variable winds and sea breezes. A shallow southerly change is expected to meander along the Far South Coast but current modelling indicates it may stall around Batemans Bay. So, we shoud see plenty of solid, fun though abating waves on Wednesday across most coasts thanks to the duelling swell sources.

A small south swell associated with Wednesday's stalled South Coast change (mainly sourced from strong winds rounding the Tasmanian corner) will then maintain fun 3ft+ waves at south facing beaches on Thursday (smaller elsewhere thanks to the direction and lack of E/NE swell). 

However, we are at risk of southerly winds encroaching the region during the day - possibly early morning in the Illawarra, but perhaps delayed enough north from Sydney to allow a few hours of clean conditions. It looks like a bit of an erratic day though, so be prepared for a rescheduled diary (earlier will be better).

Easing southerly swells are then due Friday with abating winds, probably light and variable early with weak sea breezes. 

This weekend (Feb 22 - 23)

Not much to get excited about this weekend. 

Most of our mid-week swell sources will have declined significantly by Saturday morning, so we’ll start proceedings with small surf with and light winds. 

Freshening NE breezes are expected into the afternoon and they’ll gradually pick up pace through Sunday, concurrently building a local NE windswell that should reach 2-3ft+ by the afternoon - though quality won’t be great. 

Let’s fine tune things in Wednesday’s update.

Next week (Feb 24 onwards)

An active monsoon trough is expected to slowly redevelop throughout the next week or two, stretching from the Northern Coral Sea down into the South Pacific.

It’s quite likely that we’ll see one or two tropical cyclones develop within this pattern but on their own they’re not of much use to us - especially if they’re embedded in the NW flow (which usually enhances their NE flank, i.e. aimed away from our region).

Right now it’s too early to have confidence on specifics, but the broadscale pattern does look supportive of a developing trade flow across the Northern Tasman Sea, and there’s a fair chance we may see this become supercharged by one of the tropical systems - so there’ll be plenty to keep an eye on over the week as the models draw closer to this time frame. 

See you Wednesday!