Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Wed 26th Jan)

Forecast Summary (tl;dr)

• Long range inconsistent E swell Thurs , easing through Fri with N'ly winds, light inshore early
• Small E swell pads with N'ly winds Sat, variable Sun with E swell bumping up a notch
• E swell slowly builds Mon with light/variable winds
•  E swell muscles up Tues next week as tropical low drops into South Pacific swell window, peaks Wed. Uncertain wind outlook for Wed, S'ly change likely
• S swell likely in the mix Wed/Thurs, tending to strong S/SE to SE swell as high pressure surge and trough combine later next week
• Tropics remains active, stay tuned for updates

Recap

Swell from the E generated by a low pressure system drifting south through the Tasman, punched at the upper end of the f/cast range through yesterday with surf in the 3-4ft range and generally light winds. Morning land breezes tended to light N to NE sea breezes. Size has eased back a notch today with surf in the 3ft range and light winds providing more glassy conditions. With the slight drop in size and period , surf has become more peaky and suited to a bigger range of beaches. Winds are now tending to light E’ly breezes.

Plenty of energy from the E yesterday

This week (Jan 26-28)

Our Summer blocking pattern has proven to be a favourable pattern for surf and that looks to continue. At the moment a reinforcing high pressure system is sliding into the Tasman Sea below Tasmania. It’s weak at present (1019 hPa) but expected to strengthen over the coming days and it will have the pressure gradient tightened on two fronts. First, from the west as a trough/low tied to the Southern and Indian Oceans moves through WA and SA and then from the East as a tropical low drifts into the slot from behind New Caledonia this weekend. That spells a lot of surf ahead.

In the short run the approaching trough system will see a regime of N to NE winds become established. Long range E swell fills in tomorrow but based on observations from further north this swell is likely to be a little underwhelming. Expect sets in the 3ft range but they will be very Lully and slow at times. Light morning winds will tend to NE sea breezes and freshen in the a’noon.

The working week ends with a typical summer’s day. Light to mod N’ly winds will tend NE and freshen during the day. Leftover long range E swell will provide a few 3ft sets early but they will become few and far between and trend downwards in size through the day. Small amounts of shorter period E swell will be in the mix, enough to offer some peaky options on the beach breaks.

This weekend (Jan 29 - 30)

Few tweaks for the weekend f/cast. Not a great deal of action Sat with residual E swell trains providing surf in the 2ft range and mod N to NE winds expected. There won’t be much more than a few little beaches around.

Sun looks a bit better. E’ly winds perk up in a wide band from the North Island back in towards the Tasman Sea from Thurs, as result of a large band of high pressure beginning to be squeezed by tropical low pressure. Sunday will see swell from this source pick up a notch, into the 2-3ft range. Winds should lighten as a trough stalls somewhere on the South Coast. EC model has this trough stalling further north so a weak S’ly change may extend up as far as Sydney. We’ll fine tune that change on Fri.

Next week (Jan 31 onwards)

Local winds look fantastic to start the new week. Pressure gradients drop right out and weak land and sea breezes should see glassy conditions extend well into the mid-morning or midday.

E swell will be on a slow build, initially from the cradling fetch of E’ly winds extending from the North Island into the South Pacific and back into the Tasman Sea. A classic looking summer fetch.

Pushing down onto that cradling high will be a tropical depression (possible cyclone) See below.

Tropical depression perfectly in the slot

Swell on Mon will push up from the 2-3ft range into the 3-4ft range during the day.

Light E’ly winds on Tuesday shouldn’t interfere too much with a further building in E swell. 3-4ft during the morning, muscling up further into the 4-5ft, possibly 6ft range during the a’noon as longer period swell trains start to make landfall.

There’s still some question marks over the outlook from next Wed onwards. For sure though, strong E swell will be in the water, likely in the 6ft range. GFS does have a stronger system approach the coast before a slight Northwards movement, while EC has a weaker system track slowly southwards through the Tasman. Based on that, we’ll leave some room for fine-tuning the f/cast on Fri. A S’ly wind change is also possible Wed as a front and trough enters the Tasman Sea. Pencil in Wed for a potential great day once we dial in these wind shifts.

The rest of next week is likely to see swell slowly decline from a peak on Wed, with plenty of E swell lasting the week.

S swell from the cold front and trough is expected to trend to the S/SE as a major new fetch occupies the Tasman sea adjacent to NSW later next week.

A strong high at southern latitudes and trough through the Tasman strengthen this SE fetch, leading to plenty of short range SE swell building later next week with winds from the same direction.

The monsoonal surge remains active across Northern Australia, extending into the Coral Sea and South Pacific Convergence Zone so a high likelihood of more tropical low pressure development remains into next week.

Check back Fri for the latest look at this and the action ahead next week.