Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Mon 12th May)

Features of the Forecast (tl;dr)

• Punchy E/NE beachies Tues with generally light winds
• Easing S groundswell Tues
• Easing size from Wed
• Shallow S-SE change Thurs
• Slight kick in E swell Fri with winds easing off
• Strong S surge Sat sees winds and S swell increase
• Sizey mix of S swells likely Sun with winds easing through the day
• Fun S swells likely early next week
• Dynamic outlook next week with prospects for low pressure development and sizey surf increasing in Tasman- check back Wed for latest updates

Recap

Generally fun waves over the weekend with Sat seeing a small blend of SE and E swells to 2-3ft, clean early before a light onshore flow in the a’noon. Similar winds for Sun, with a morning land breeze and a’noon E-E/NE breeze. E’ly swells kicked up a notch to 3ft through Sun and have ramped up further into today with widespread 3-4ft surf. Longer period S swell is also showing 3ft sets at S facing beaches (see below).Offshore winds this morning have provided clean to semi-clean conditions (just a little leftover bump and lump around from a lingering onshore flow) with another day of light a’noon E’ly to E/NE’ly breezes expected. 

Bit of lump and bump on it but nice size and swell direction this morning 

This week (May 12-16)

The synoptic situation has been sluggish with a large high (1030hPa) still sitting in the Tasman still maintaining a firm ridge up the sub-tropical coast with a weaker pressure gradient through temperate NSW. Weak supporting high pressure does drift into the Tasman this week with multiple coastal trough lines suggesting instability and variable winds before a weak S’ly change Thurs. The recent pattern of very strong highs moving through the Bight into the Tasman then resets over the weekend with a high likelihood of another surge of S-SE swell during this period. The southern swell window remains fairly suppressed by high pressure but there are good signs a stronger polar low later this week will send a useful long period S swell up the pipe over the weekend. 

In the short run, conditions look good through tomorrow with light land breezes and light/variable breezes through the day. Clean conditions should extend right through the morning at least, possibly into the a’noon. Another good day of mixed E/NE swell to 3-4ft (maybe some occ. bigger 5ft sets in the mix) with S groundswell to 2-3ft, easing through the day. 

That E/NE swell will be on the decline through Wed as the Tasman Sea/Coral Sea fetch has been breaking up and the tropical low in the South Pacific skipped away to the SE quickly. As a result we’ll see swells easing to 3ft, and just slowly backing down through the day. Plenty of fun waves still around through and with another day of light morning offshores and very light variable breezes during the day (likely staying even lighter than Tues so clean most of the day) Wed should see plenty of fun small wave options across the region. 

Thurs looks like a possible lay day as a coastal trough moves north and brings a shallow S’ly tending S/SE change that will make most open beaches wind affected. Early winds should be OK across the Northern Beaches before clocking around S-S/SE. Size looks to be at a low point for the week with E’ly swells around the 2ft mark. 

Wave models are suggesting a brief bump back up in size Fri- which looks hard to justify from current synoptics. There are so many active E’ly fetches though thats it’s worth taking it at face value with E’ly swells (slightly longer period, so better quality) showing to 2-3ft with an occ. bigger set. Thursdays S-SE change washes out to light morning W-SW breezes before tending light/mod SE in the a’noon. 

This weekend (May17-18)

We’ll review the timing through the week, but under current modelling we’ll see the next strong S’ly surge develop Sat as the next big high moving through the Bight rapidly builds a strong ridge up the eastern seaboard. That would see a brief period of lighter SW winds inshore early before S’lies kicked up to fresh/strong paces through the day, bringing a new spike in mostly short range S swell into the 4-5ft range (bigger on the Hunter). 

Sunday then sees a muscular blend of S swells, mostly short range tending to better quality from the front, in the 4-6ft range. We may see the ridge relax quite rapidly in temperate NSW with S-S/SE winds washing out to light SE-E breezes in the a’noon. Not enough to clean things up but if you can tolerate some lump and bump there should be surfable options Sun a’noon. 

Next week (May 19 onwards)

Early next week looks good with light winds and a mix of mostly S swells to 3-5ft at S facing beaches. We’ll pencil that it for now.

Model divergence then kicks in with GFS suggesting the high moves NE into the Tasman, bringing calm, light winds for temperate NSW, with an easing ridge for the sub-tropics. 

EC has a more bullish outlook with another massive high moving in from the Bight and short range feature (trough or low pressure) building in the Tasman with a powerful and broad S then SE-E fetch developing through the Tasman. Under this scenario we’re looking at a very sizey event into mid next week, possibly a sustained week of solid surf although winds will be a problem apart from the QLD points. 

With such a dynamic outlook and model divergence there’s low confidence in specifics this far out. 

The current troughiness does lend weight though to the more bullish outlook. 

We’ll come back Wed and see how it’s shaping up.

Seeya then!