Sydney Hunter Illawarra Surf Forecast by Ben Matson (issued Mon 18th Apr)

Forecast Summary (tl;dr)

• Good easterly swell until Thurs, peaking Wed with early offshore winds
• Tricky winds Tues; light early then freshening N'ly
• S'ly swell behind a S'ly change sometime Wed (prob PM), easing Thurs
• Solid E/NE swell building over the weekend, light winds
• Intermittent southerly swell for most of the forecast period

Recap

Nice mix of east and south swells over the weekend, the former held 2-3ft sets both days but the latter pushed 4ft at times on Sunday, at south swell magnets. Today has seen the south swell ease back and the east swell muscle up to 3-4ft. Winds have been generally light and variable with afternoon sea breezes.

This week (Apr 19 - 22)

The northern Tasman trough that generated the last few days of east swell has intensified a small new fetch just off the west coast of New Zealand's North Island (see below).

This will generate a couple of pulses of east swell, that'll keep the coast flush with energy through most of this week.

The overall pattern should maintain inconsistent 3ft, almost 3-4ft sets from Tuesday through Wednesday and even early Thursday, but we should see a half-day of more consistent, and slightly bigger surf (say, 3-5ft) at times on Wednesday as longer period energy makes landfall.

Winds look a little tricky this week though, thanks to a passing trough and approaching cold front.

Tuesday should start off clean with light N/NW winds but they'll freshen N/NE through the day, and then veer NW overnight as the trough pushes across the region and the front rears up from the south.

Now, the models a little split on the timing, strength and alignment of this front so the specifics may move around a little, but the early session (Wednesday) looks best right now, and we may see an arvo pulse of short range south swell too (maybe 3-4ft at south swell magnets on dusk).

Easing swells from the east and south are due early Thursday, along with a morning offshore wind, however the afternoon will herald the arrival of a better long period south swell, generated by the parent front/low well southwest of Tasmania (on Tuesday/Wednesday). This should rebuild wave heights into the 4-5ft range at most south facing beaches, with easy 6ft+ sets at south swell magnets such as the Hunter.

The only downer here is that me may also see an accompanying southerly change clip the coast (though it will be shortlived). We'll take a closer look at that in Wednesday's notes.

Friday will then see easing southerly swells from 3-4ft at south facing beaches (4-5ft+ south swell magnets such as the Hunter) though the steep direction will result in much smaller surf elsewhere.

Light variable winds are due south of Sydney but locations to the north - especially around the Hunter - may see a lingering S/SE flow as a ridge develops across Northern NSW.

This weekend (Apr 23 - 24)

We've got some really nice surf expected this weekend.

The remnants of the Tasman trough - responsible for the weekend's east swell plus the upcoming easterly energy this week - will reform a second time, NE of New Zealand around Tuesday (see below), reaching maturity around Wednesday and Thursday.

This fetch has been upgraded in the last few model runs so we're looking at some really nice E/NE groundswell building through Saturday, reaching a peak on Sunday afternoon with inconsistent 4ft sets at open beaches.

We'll also see some smaller underlying long period southerly swell from a robust though poorly aligned storm track below the continent.

A weak ridge of high pressure should create light winds.

Book in a session or two if you can!

Next week (Apr 25 onwards)

The weekend's east swell will gradually ease into the start of next week, and early indications are for a summeresque ridge of high pressure across the northern Tasman Sea, which should supply user-friendly E/NE energy for open beaches for much of next week.

The vigorous Southern Ocean storm track alluded to in previous forecast notes has been pushed a little further south, and more zonal (west-east) in orientation, which has suppresed size expectations for the medium term outlook - though there still appears to be a neverending source of small, long period southerly swell for the forseeable future. Which ain't a bad thing.

See you Wednesday!