Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Mon 26thDec)

Forecast Summary (tl;dr)

• Small, weak surf extends into Boxing Day and Tues with minor NE windswell possible Tues
• Slow increase in E/NE swell Wed PM persists into Thurs with possible SW-S winds Thurs
• Plenty of Chunky E/NE swell expected Fri and into NY weekend with mostly onshore winds
• More E swell expected into first week of Jan- slowly easing into mid week
• Still monitoring the tropics as MJO fires up monsoon trough

Recap

Xmas Eve had a few fun waves with a nice pulse of E/SE swell from across the Tasman filling in through the a’noon with some tasty 3ft sets under light winds after an undersized start. Xmas day saw wave heights wind back and with light S’lies on hand conditions were a bit second hand for an Xmas Day surf. Today is seeing small, weak leftovers in the sub 2ft range (mostly 1-1.5ft) with light NW winds now tending N to NE and expected to kick up further through the a’noon. An active E’ly surf pattern sets up through this week, details below.

Some fun sets XMas Eve a'noon under light winds

This week (Dec 26-30)

We’re now on the cusp of a dynamic, tropical induced blocking pattern with low pressure hiving off an active monsoon trough in the Coral Sea and meandering in Coral Sea before drifting down into the Northern Tasman. The high pressure belt holds good support for this low pressure area with reinforcing cells stacking onto a slow moving system located at South Island latitudes. This will see an extended E’ly swell event, initially favouring sub-tropical areas and then spreading south to temperate NSW later this week. 

In the short run we’re looking at a couple of scrappy days with not much surf and N-NE winds increasing as high pressure sits in the Tasman and a trough line approaches from the W. Expect increasing N’lies through Tues and Wed. Tiny surf is expected through Tues and into Wed.

By Wed a’noon we should see a small bump in size from both local NE windswell and a small amount of mid period E/NE swell starting to filter down from the large low pressure system in the Coral Sea. Keep expectations low but through Wed a’noon there should be some surfable 2ft waves, under fresh NE winds.

Into Thurs and we’ll start to see a more meaningful increase in E/NE swell as the southern limit of the Coral Sea fetch starts to migrate into the temperate NSW Eastern swell window (see below). Expect surf to build slowly from 2ft into the 3ft range through the day. Winds look flukey as a trough works it’s way up along the Sydney basin to Hunter during the day. An early SW flow is possible before S’lies kick in, likely tending back to an E/NE flow through the day. Stay on top of your local wind obs as local wind changes are highly likely.

By Friday winds will have firmly re-established from the E to NE as reinforcing high pressure slips into the slot. A stronger increase in E/NE swell is on the cards as the E’ly fetch continues to colonise the Northern Tasman. Both size and juice are on an upwards trend with sets to 3-4ft building to at least 4ft+ during the day, likely 4-5ft at suitable spots. E’ly winds will degrade surface quality but if you can work with that there will be heaps of juice to play with.

This weekend (Dec 31-Jan1)

Plenty of E/NE swell for New Years Eve, along with plenty of E to NE wind. There’s still some substantial model divergence to deal with. GFS has a retrograding low pressure area pushing close to the NSW Coast during NYE with size pushing up into the 6ft+ range at least under an E-NE flow. EC slowly slides the large area of low pressure towards the North Island with smaller but better quality E/NE swell in the 4-6ft range and lighter E/NE-NE winds. Either way there’s going to be plenty of swell and onshore winds to deal with.

New Years Day will have stacks of strong E/NE swell and allowing for a bit of revision through this week confidence is high we’ll see surf in the 4-6ft range. We should see a slackening of the local pressure gradient leading to lighter E to NE winds. We’ll finesse those winds through the week. 

Next week (Jan2 onwards)

Strong E/NE swell continues into the first week of Jan as a low pressure trough sits in the Northern Tasman off the NSW Coast. We should see a slow easing trend through the first couple of days of the New Year, although maintaining plenty of size. 

A broad fetch of E/NE winds remains active from the North Island down into the Tasman which should hold surf in the 3ft range through into the middle of next week.

Winds look tricky. A long, angled trough line is expected to form off the Southern NSW Coast early next week. That may bring a S’ly change as early as late Mon or Tues with lighter winds Mon morning worth pencilling in.

S’lies may then kick in Tues as the trough joins up (potentially) with the low remnants. That could see both building short range S-SE swell and residual E/NE swell into the middle of next week. Confidence is low on those predictions so make sure you check back in Wed for the latest revisions.

Longer term and cyclogenesis looks likely off the Far North QLD coast next week- with another tropical depression or cyclone forming in the South Pacific near Tonga. It’s too far out to have confidence in the surf potential for temperate NSW from these systems but we’re certainly in a very active tropical phase so check back in Wed and we’ll see how it’s shaping up. 

Plenty to keep us occupied in the run up to NYE.