Eastern Tasmanian Surf Forecast by Steve Shearer (issued Wed 7th Sep)

Features of the Forecast (tl;dr)

• Leftover SE groundswell at small levels Thurs
• NE windswell  building Thurs with fresh NE winds, slowly easing Fri with improving winds
• Chunky NE windswell rebuilds Sat with improving winds
• Easing back to tiny on Sun
• S swell likely Mon next week
• Uncertain outlook due to potential low in the Tasman next week, stay tuned for updates!
• Chunky NE windswell likely towards the end of next week

Recap

More swell from the S since the last forecast with yesterday seeing sets to 2-3ft under light S to SE winds. Size has eased back to 2ft at S facing beaches today with winds freshening from the N to NE, which will see a solid NE windswell develop. Details below.

This week and next week (Sep7 – Sep 16)

The Tasman low is out of the swell window and a large high is now moving over Tasmania to take up position in the Tasman Sea at a southerly latitude typical of the high pressure belt under the La Niña phase of the ENSO cycle. The high will move E with a N’ly flow rapidly developing as pressure gradients get tightened by an approaching front, complex low and trough line, generating solid NE windswell.  That will dominate the rest of the week and weekend with the low moving out into the Tasman in conjunction with a series  of cold fronts early next week.

In the short run and freshening N’lies build into a tight fetch off the NSW South Coast into Bass Strait tomorrow, with a rise in NE windswell expected. Expect winds to get up into the 20-30 knot range, with surf building from 4ft up into the 6ft+ range. In additions there will be some small SE groundswell in the mix to 3ft, become over-ridden by the NE windswell in the a'noon as it eases.

Size peaks in the 6-8ft range Fri morning under fresh NNE winds with size and winds easing through the day, although still remaining solid. 

Sat morning looks the go, as solid NE swell holds in the 4-5ft range and winds tend more NW to W/NW as a complex low, front and trough approach from the W. That should see the best surf of the week before size eases off during the a’noon as the fetch gets shunted off to the E.

Sunday sees small leftovers below 2ft.

Into next week and there’s still a fair amount of model divergence happening which suggests more tweaks to the forecast for next week on Friday.

EC continues the stalled low, with a resultant SW’ly to S’ly flow forming through Mon, before a weak low forms in the troughy remnants of the weekends instability. That would suggest small surf Mon with developing S swell , with a small pulse of S swell late Tues from a passing front, before a couple of days of small SE swell as the low sits off southern NSW.

GFS is much more bullish, with a major front bringing a stiff S’y change Mon PM, and a chunky S swell for later Tues/Wed in the 3-4ft range at  S facing beaches with S to SE winds.

Looks like another round of NE winds towards the end of next week, with another mid-latitude low and trough approaching from the W. This period of instability and enhanced troughiness reduces confidence in even medium range forecasts, due to models struggling to resolve the extra dynamism in the atmosphere. Another round of chunky NE windswell looks highly likely for there end of next week.

Without any major swells on the radar for early next week, we’ll pencil in a S quadrant swell for Tues/Wed and a NE windswell for later next week and see how it’s shaping up when we come back Friday.

Seeya then.