Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed Oct 13 )

Forecast Summary (tl;dr)

• NE windswell building Thurs, peaking Fri morning with winds tending offshore
• Small, mixed bag Sat, tending to babyfood during the day with all-day offshore winds
• Mod S swell pulse Sun with offshore winds in the AM
• Reinforcing S pulse Mon with winds tending N'ly
• Onshore winds set-up Tues into Wed with increasing SE windswell
• Potential stronger SE/ESE swell to end next week and into the wekeend, stay tuned for revisions

Recap

A direct onshore flow and not much in the way of significant swell has seen very poor surf continue on from Mon into Tuesday and now today. Winds have generally been straight out of the SE to E with surf in the 3ft range, as a large high drifts in the Tasman. Those winds are now in the process of shifting NE with some increased NE windswell now on the radar to end the week.

This week (Oct 13-15)

Northerly winds are now in the process of becoming established and freshening, as a 1025hPa high SE of Tasmania has pressure gradients tightened along it’s western flank by an approaching complex low system in the Eastern Bight. This complex low moves over the interior of Victoria through tomorrow before consolidating near Tasmania over the weekend. It’s a continuation of the unstable, dynamic pattern we’ve been seeing for most of the Spring, associated with the developing La Nina phase of the ENSO cycle.

Tomorrow will be full blown NE winds, potentially verging on low end gale force in the a’noon, when they tend more N’ly in direction. That means surfing in the fetch but if you can tuck in behind a headland or even use the prevailing coastal alignment you’ll find increasing levels of NE windswell to ride. Expect size to push up into the 3-4ft range across the region, with the Hunter curve picking up a an extra foot due it’s proximity to the fetch.

The complex low drives a front across the state Fri and this is good news for surfers as winds will now tend NW, then W’ly as the front sweeps across the state. Solid NE windswell in the 3-5ft range rapidly improves in quality as winds tend offshore. Like all NE wind swells though it will drop away quite quickly as the proximate fetch gets shunted eastwards by the prevailing front and approaching low. Friday looks to be the best day of the f/cast period.

This weekend (Oct 16-17)

The weekend looks a little undersized compared to Mon’s expectations. The low moving East of Tasmania pushes gales out of Bass Strait but that fetch is pushed back to Sat PM, which suggests Sat will be very small, consisting of NE leftovers in the 2ft range and a few traces of S swell from a frontal progression through the lower Tasman. Expect surf to ease further during the day, with clean babyfood in the 1-2ft range on offer during the a’noon. All day W’ly winds will keep surface conditions groomed.

Sunday’s surf gets a hair cut in size. Small S swell from the Bass Strait fetch sees some 3-4ft surf at S facing beaches through the morning, with a few 4-5ft sets at the more reliable swell magnets. Early offshore winds generated by the parent low moving E of Tasmania and across the Tasman sea, then tend to light ESE breezes in the a’noon.

Next week (Oct 18) and beyond

Next week looks even more La Nina influenced than this week, as a strong high moving at an unseasonably southwards latitude moves into the lower Tasman and directs a strong onshore flow.

South swells begin the week, from a variety of source fetches. Sundays fetch moving NE of Tas from the parent low brings an increase in S swell with mid period swell in the 3-4ft range expected, likely bigger 4-5ft on the Hunter before surf eases through the day. Winds look a bit tricky with a “synoptic vacuum” formed by a vague area of high pressure drifting off the NSW Central Coast. Thats likely to see winds from the NW, possibly N, before tending NE during the day. 

By Tuesday our next pattern will be setting up as the large high moves into position south of Tasmania, with a trough of low pressure along the leading edge of the high bringing a strong S’ly change which is expected to tend SSE to SE through the day. That will restrain surfing options to sheltered corners and with 3ft of S swell on the menu poor surf is expected. An increase in short range SE swell through the a’noon may offer up a few cleaner alternatives in sheltered Bays, but the short period won’t be of much use in getting in to really sheltered spots.

By Wed, the high will be set up well south-east of Tasmania, with a broad coverage of almost the entire Tasman sea with SE winds. Not a typical Spring pattern. Onshore winds will limit surfing options but we’re likely to see increasing amounts of SSE to SE swell building across the region. Models are still in a state of flux due to the expected presence of multiple troughs in the Tasman sea.

That leads to very low confidence in predictions for the second half of next week. Depending on the location of the troughs we’re liklely to see increasing ESE swell through Thurs and Fri, with potential for a more solid burst of E/ESE swell into next weekend if a trough deepens into a low near the North Island later next week.

Expect plenty of revision Fri as we grapple with the unstable and dynamic Tasman sea through next week. 

Check back Fri for a fresh and full update.