Multiple swell pulses ahead as STC Dovi slides down the Tasman Sea
Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Fri 11th Feb)
Forecast Summary (tl;dr)
- Freshening S to SE winds Fri with a blend of small surf from the E/NE and building S’ly wind swell
- Fresh S to S/SE winds Sat with a blend of S wind swell and small amounts of E/NE swell
- Easing winds Sun with a blend of strong swells from the E/NE and SE-E/SE
- Pumping Mon with light winds and strong E/SE-SE swell
- Possible reinforcing pulse E/SE swell Wed with NE winds developing
- Flukey, long period S swell possble Wed, easing Thurs
- S'ly change Fri
The trend has been down since the last f/cast. Yesterday saw some early 3-4ft surf which eased through the day. Clean early before N’ly winds and a late S’ly change. This morning has seen a pattern change with a S’ly flow across the region, lighter SW inshore early north of the Harbour, and some leftover 2-3ft surf. This was swamped by a morning high tide at most locations. S to SE winds are now on the increase as a high pressure ridge builds and TC Dovi enters the Coral Sea, with plenty of swell ahead.
This weekend (Feb 12 - 13)
The headline news is TC Dovi, which formed north-east of New Caledonia Wed a’noon and is moving SW at about 12 knots inside the Coral Sea. At 5am this morning TC Dovi is about 730 nautical miles E/NE of the Queensland border. That puts it in our swell window and although Dovi is currently Cat 3 it’s surf potential is limited by the compact fetch and expected increased speed of movement over the next 24 hrs. Essentially the compact fetch of hurricane force winds will “outrun” the area of swell production, limiting the amount of swell energy it can generate.
Concurrently, a long NW-SE angled high pressure ridge is being energised by the south-wards moving cyclone, forming an impressive fetch of SE winds through the central Tasman Sea. This SE fetch will be the main swell source for the region, with a smaller E/NE cyclone swell proper, overshadowed by this stronger swell.
Saturday will be dominated by strong S to SE winds, with only a brief window of lighter winds inshore before winds crank up in excess of 20 knots. Expect a slightly undersized start in the 2-3ft range before a building trend in mostly short period SE wind swell, reaching the 3-4ft range, bigger 4-5ft on the Hunter.
Wind will be the main problem Sunday as well, with SE winds through the morning, slowly backing down during the a’noon as the high pressure ridge eases and TC Dovi undergoes extra-tropical transition and impacts the North Island.
Surf will muscle up Sun, from two sources. The prevailing SE swell should see increasing wavelength with size in the 3-5ft range. Through the day longer period E/NE swell will see chunky though Lully 4-5ft sets. I’m still expecting some outliers as far as wave heights go with these two swell sources in the water, particularly at known NE swell magnets which may focus the longer period E/NE swell. Hopefully winds drop out quicker than expected allowing the swell to be utilised to it’s fullest potential.
Next week (Feb 14 onwards)
Models now show the remnants of the cyclone undergoing extra-tropical transition as it slides towards New Zealand with areas of severe SE gales developing on the south-western quadrant. These winds aren’t perfectly aligned for the region but there’s enough strength in the fetch for plenty of incoming energy. The tail end of the ridge also activates strongly through the lower Tasman over the weekend, adding to the incoming swell energy. In short, there’s still a lot of incoming swell trains being generated for early next week.
Monday still looks great. A light morning NW flow and E/SE swell in the 4-6ft range should see a wide swathe of pumping surf across the region. Through the day those winds will tend NE, staying light/mod, and a slight easing trend will set in.
That easing trend becomes more established Tues, with the N’ly flow becoming more entrenched with it. Expect some leftover 3-4ft sets from the E/SE, dropping right back into the 2ft range during the a’noon. NE winds will freshen into the 20 knot range.
A last pulse of E/SE swell is expected Wed, generated by gales out of Cook Strait. This fetch now looks a lot more constrained in time and space compared to Wednesdays notes, so we’re only looking at a few 2-3ft sets through Wed, with another day of N’ly winds expected. Potential exists for a slight bump in NE wind swell during the a’noon, with Thursday a better bet for NE windswell.
Also a potential swell source is some long period refracted S swell generated by a deep polar low stalling under the continent on the weekend/Monday. Keep expectations low but reliable S swell magnets should see some 2-3ft sets from this source Wed, easing into Thursday.
Longer term and it looks like one more day of N’lies Thurs before a S’ly change Fri with some small S’ly swell expected for Fri and next weekend. No doubt we will see some revisions on that as the week rolls on.
Check back Mon for the latest updates.
Plenty to occupy the short term so enjoy that and have a great weekend!