Eastern Tasmanian Forecast by Steve Shearer (issued Wed Sep 11th)

Features of the Forecast (tl;dr)

• S swell pulse Thurs PM, holding into Fri before easing with S’ly winds shifting NW
• More strong S swell likely Sat, into Sun before easing
• S groundswell pulses Mon/Tues with offshore winds
• Possible small NE swell Thurs next week- check back Fri for updates

Recap

Tiny NE windswells to 1ft yesterday with slightly more size (still tiny) to 1.5 occ. 2ft today under mod/fresh NW winds before a gusty S/SW change. 

This week and next week (Sep11 - Sep 20)

We’ve got high pressure moving across the Tasman with a much stronger dual-centred high tracking into the Bight. A trough between them moves offshore tomorrow forming a fast moving trough of low pressure in the Tasman, which tracks rapidly NE. We’ll see a spike of S swell from this system, downgraded from Mon. A following front and trough now looks stronger, earning an upgrade. More S swell into the middle of next week from polar activity tracking NE with good winds expected. Let’s dig in.

We’ll the developing trough and front bring mod/fresh winds o’night and into tomorrow with winds then shifting NW and W during the day as another frontal system approaches. Small surf from the S in the 2ft range will ease through the day. 

Not much on Fri with tiny S swells to 1ft or so and W’ly winds before they shift SW-S in the a’noon as a trough moves NE off the Tas coast.

Into the weekend and we’ll see fresh SW-S winds develop as a stronger front and trough move over Tas and into the Tasman sea. That will see a steep increase in new S swell reaching up to 5-6ft at S exposed beaches by dark.

Similar size into Sun morning before swells ease through the day as the fetch moves NE. Mod S/SW winds then tend W/NW-W as another front passes over the state.

We’ll see another complex of S swell trains make landfall from Mon. Mostly mid period S from the frontal intrusion into the Tasman (see below) but there will be come much longer period swells in there from polar sources. 

Mon and Tues are looking good with mostly offshore winds favouring S facing beaches.

At this stage, under current modelling we should see size to 3-5ft at S facing beaches Mon , holding into Tues before easing during the day. We’ll finesse size and timing on Fri but at this stage it looks pretty good.

The rest of next week now looks quite small. There’s still some suggestion of a N’ly infeed into a trough from EC but it looks ,much weaker than on Mon. 

Small surf looks likely for the second half of next week with some possibility of small NE windswell.

A strong front and low approach the Tasman late next week or weekend and certainly offers the chance of a major S swell. Long way off and confidence is low so check in Fri and we’ll how it’s shaping up.

Seeya then.