Eastern Tasmanian Forecast by Steve Shearer (issued Fri October 18th)

Features of the Forecast (tl;dr)

• Easing swells Sat AM with SW winds and freshening S’lies in the a’noon
• Spike in S swell Sat PM extending into Sun, easing quickly Sun PM
• Small long range E/NE swell on the radar for Tues/Wed week
• Large S swell possible Fri into the weekend as low forms in Tasman, check back Mon for latest

Recap 

Sizey E-NE swells to 3-4ft yesterday under N tending NE winds. Today has seen freshening N’lies with rain and large and ragged NE swells building to 5-6ft. 

This weekend and next week (Oct 18- 25)

No great change to the weekend forecast. A low is expected to move E of Tasmania o/night and form a broad low pressure trough in the Tasman driving SW’ly then S’ly winds up the  Tasmanian east coast before moving NE as a surface low over the weekend. That will be the second surface low in succession to form in the Tasman and we may yet see a third develop later next week. 

We’ll see a brief period of clean conditions under SW winds tomorrow morning with easing NE windswell to 2-3ft before S’ly winds kick in hard and new S swell builds to 3-5ft in the a’noon. 

By Sunday we’ll see a morning peak in S swells to 4ft with size easing quickly as the low and fetch moves NE into the Tasman. S’ly winds will also ease quickly through the day. 

A tiny start to the new week with small leftovers to 1ft or so Mon and into Tues. By Tues a’noon we should see some small E/NE swell  as swells fill in from a tropical depression drifting south from Fiji.

It should be a slow build as initial pulses from the tradewind band make landfall with sets building to 2ft by close of play.

Stronger, longer period swells show on Wed with 3ft sets through the day. It will be coming from a fair way away so expect pulses and slow periods. Light morning SW-S breezes should offer primo conditions before winds tend NW. All in all, Wed looks good.

We’ll see E/NE swells extend into Thurs AM with a  slow ramping down in size and consistency through the day. Still plenty of quality on offer with freshening W’ly winds.

Further ahead and another dynamic outlook is ahead. Major models are in agreement that another front/trough system forms a surface low in the Tasman late next week, possibly an order of magnitude greater than the current iterations (see below). Under current modelling we’d expect stiff SW winds to develop Fri with a very sizey S swell developing and extending into the weekend, up into the 8ft range. We may see a second phase of the swell as low pressure stalls or retrogrades from near the South Island, suggesting a reinforcing pulse of E/SE-SE swell early week of 28/10. Too early to have any confidence in specifics of size or timing there. 

Certainly something to get excited about though, especially as we move into the second half of October.

Check back Mon and we’ll see how it’s shaping up and until then, have a great weekend!