Sydney Hunter Illawarra Forecast by Steve Shearer (issued Mon May 20th)

Features of the Forecast (tl;dr)

• Plenty of S swell Tues, tending to more favourably angled S/SE-SE swell in the a’noon 
• Fun sized SE swell Wed with morning offshores tending S’ly
• Easing swells Thurs 
• Possible small bump in S/SE swell Fri with nice morning winds
• More S-SE winds this weekend, possibly with increase in local SE swells if low pressure trough forms
• Otherwise, small S’ly groundswells this weekend
• Small surf expected next week as high pressure finally moves into Tasman Sea.

Recap

Wild and windy day Sat as a low pressure trough deepened off the coast with strong SW-S winds and raggedy, raw S swells to 6-8ft at exposed breaks, smaller in more sheltered bays. Size settled into the 4-6ft range on Sun with winds a little more manageable. This morning is seeing cleaner conditions with a morning offshore breeze and an energetic surf rebuilding into the 4ft+ range.

Raggedy, energetic S swell over the weekend

This week (May 20-24)

Another massive high is mooching in the Bight, with a snails pace of eastwards movement expected this week. Wind-wise that will anchor a S’ly flow along the Eastern seaboard for the week with enough slack in the gradient for morning land breezes to develop. The remants of the weekends low pressure trough are currently being reinforced by a another cold front and expected to form a broad low pressure system in the Tasman in the short term which will supply some fun waves this week with an easing trend into the weekend. Another rebuild in S-S/SE swell looks likely for the weekend.

Still some strength in that S’ly flow tomorrow with a morning W/SW-SW flow north of the Harbour and S’ly bump across S exposed breaks. Size from the S-S/SE running at similar size as today, 3-4ft with the occ. bigger set. SE-E/SE swell from the broad low in the Tasman should bump to 3ft in the a’noon, helping out wave heights at more sheltered spots.

Wed should see a more established offshore breeze for the morning, smoothing out more of the S’ly bump before winds clock around S’ly, at lighter paces. Fun sized SE-E/SE swell to 3ft beckons, with best conditions before the S’ly kicks up.

By the latter part of the week the low pressure system will have scooted over NZ, out of our swell window, with a broad, weak fetch of S/SE winds in the Tasman. Thurs should offer some small, fun beachies in the 2 occ. 3ft range with light morning offshore winds and light S’ly breezes in the a’noon. 

Similar winds for Fri. Models are suggesting a small bump in size Fri morning from a lingering fetch near the South Island. Doesn’t look like there is too much in it- a few 2 occ. 3ft waves under clean conditions so worth an early. Otherwise, easing back to small 2ft or so through the day. 

This weekend (May25-26)

High pressure still sits SW or S of Tasmania this weekend, possibly with a reinforcing cell.  That will maintain or increase a S-SE flow along the coast. The curve ball is a small trough of low pressure suggested by GFS (see below), which would increase the SE flow and generate an increase in short range S/SE-SE swell through Sat and hold through Sun.

Absent that trough we’ll see a lighter S’ly flow for the weekend.

Polar low activity remains better aimed at New Zealand and Pacific targets (Raglan has been pumping from these swells) and we’ll see these lows steered into the Tahitian swell window over the weekend and early next week.

Glancing blows from long period S’ly swells should see some 2-3ft surf across S facing beaches over the weekend. 

Next week (May 27 onwards)

High pressure should finally move into the Tasman early next week, with winds becoming light at least into the middle of the week.

No major swell sources on the radar. S’ly groundswell should offer up a few sets Mon before fading out.

Looks like a few small days then into the middle and end of next week.

There some suggestion of a trough line forming off the NSW Coast later next week, with no concrete surf potential as yet attached to it.

We’ll keep eyes on that and see how it looks on Wed.

For now, looks like a few fun days of surf this week.

Seeya Wed.