Eastern Tasmanian Surf Forecast by Steve Shearer (issued Wed Sep 21st)

Features of the Forecast (tl;dr)

• Another round of NE swell this week, first increase later Wed
• Much stronger NE swell Thurs/Fri with winds tending offshore Fri
• Easing NE swell Sat, with a new S swell PM
• S swell eases quickly Sun
• Small again through next week

Recap

No surf to speak of since Mon with just tiny background ankle-snappers in the 1ft range both days. Light winds yesterday have now transitioned to N’lies, and are beginning to freshen, marking the start of another round of NE windswell.

This week and next week (Sep 21- 30)

A few tweaks to the upcoming NE swell event. The complex low and huge trough line (extending across most of Australia!) are still tracking across the interior as forecast, with a high in the Tasman generating a NE flow across the majority of the Eastern Seaboard and down to Bass Strait. The pressure gradient is tightened as the low approaches with an increase in NE winds and swell expected through the end of the week. A small low exits the coast north of Coffs Harbour, which delays the offshore flow and maintains a N’ly wind across the region until a front brings an offshore change Fri. The return S’ly flow as another small low and front develop near Tasmania late Fri/Early Sat is expected to kick in over the weekend. 

In the short run and N’ly winds maintain moderate strength through tomorrow with NE windswell building into the 3ft range. Size is down a little because the strongest winds in the fetch are now aimed at more sub-tropical targets. There should still be some fun waves to be had.

Expect similar size on Fri. Savvy operators will pounce on the wind change as a front pushes through and winds tend W/NW then W before ending up W/SW. With fun levels of 3ft NE swell there should be some good options on the beachies. 

Into the weekend and stiff S’lies kick in as a low winds up SE of Tasmania (see below), merging with the remnants of the front and trough line.

That will see stiff S’ly winds and S swell push up into the 4-5ft range during the day. A small amount of leftover NE swell will be in the water early.

S swell eases back quickly through Sun with the pressure gradients rapidly easing and winds tending light before trending to light seabreeezes. Size in the 3ft range will ease back to 1-2ft through the a’noon.

Next week we see the troughy pattern persist in the Tasman Sea. An approaching low shifts winds NW and a leftover NE fetch in the central Tasman generates another small round of NE swell, in the 2-3ft range during Mon.

That low fizzles out as it crosses the Island state Tues, leaving a weak pressure gradient and light winds from Tues. No major swell sources on the radar so expect a few days of small surf from Tues-Thurs, mostly E/NE swell from a broad but poorly defined wind field in the South Pacific near New Zealand and extending into the Tasman Sea.

Late in the week SE winds through the lower Tasman should also supply some small SE swell into the mix.

Another mid-latitude low may push through NSW late next week, bringing instability but no real surf potential at this stage.

As mentioned before, all these troughy systems will need constant revision as weather models struggle to resolve them. Check back in Fri and we’ll update all the potential scenarios next week and take a last look at the weekend.