Eastern Tasmanian Forecast by Steve Shearer (issued Wed September 17th)

Features of the Forecast (tl;dr)

• Small S swell pulse Thurs with fresh W tending W/NW-NW winds
• Small NE windswell possible Fri PM under fresh N tending NW winds
• Small NE windswell wrap Sat with fresh NW tending W’ly winds
• Small S swell pulse Tues, easingWed
• More S swell Thurs/Fri
• Fresh W/NW-NW winds continue under a zonal pattern 
• Possible larger S swell medium term

Recap

NE windswells offered a rideable wave in the 1-2ft range yesterday under mod/fresh NW winds. Size has eased back into the 1-1.5ft range today (just surfable) with fresh NW tending W’ly winds. 

This week and next week (Sep 17 - 26)

A series of fronts are now crossing Tasmania and entering the Tasman with a parent low also moving through the lower Tasman. Weak high pressure is moving in over the continent with a highly mobile passage across the Tasman from tomorrow. Rapid movement of fronts re-occurs over the weekend with a stronger S swell signal now expected into next week.

In the short run, the rapid passage of the parent low and front across the lower Tasman generate a minor S swell with S facing beaches seeing 1-2ft surf under fresh W tending NW to N/NW winds.

Winds then shift pre-frontal N’ly again Fri and freshen before veering NW later in the day. That should see minor N’ly windswell wrap generated to 2ft in the a’noon. 

Into the weekend and we’ll see NE windswell wrap peak in the 2-3ft range Sat with pre-frontal NW winds swinging W’ly as another front races through Bass Strait and into the Tasman, weakening as it does so.

Only tiny leftovers Sun with similar winds.

Bit of a tricky outlook now on the cards for next week with model divergence a feature. First, a powerful high is expected to be in the bight offering potential for tight pressure gradients for any short range features that intrude into the Tasman. 

Not much expected to start the week. Pre-frontal W/NW-NW winds shift W/SW-SW as a weak front moves into the Tasman. Only tiny surf is expected. 

Tuesday looks more active as the weak front interacts with a lingering trough off the NSW coast to develop a fresh SW-S flow off the NSW South to Central Coast. That should generate a moderate spike in short range S’ly swell through the day, provisionally in the 3ft range. 

A reinforcing front looks to provide better quality back-up swell Thurs with SW winds Wed tending S/SW to variable Thurs.  There’s been poor model to model and run to run consensus so expect revisions when we comes back Fri. 

Winds looks to shift  NW’ly-W/NW’ly later next week into the weekend as high pressure sits to the north and supplies a W’ly flow augmented by an approaching low.

A much stronger low is then expected to approach weekend 27-28/9- likely to bring freshening winds across Southern NSW through the weekend, depending on what latitude it adopts on approach. 

Into the next week, a stronger S swell is on the cards as that low enters the Tasman. 

Both major models are suggesting a significant S swell during that period. 

Still too far off to have any confidence in specifics so check back Fri and we’ll sharpen the focus. 

Seeya then.