Southern Tasmania Surf Forecast by Ben Matson (issued Friday 21st October)

Features of the Forecast (tl;dr)

• Tiny surf, onshore winds Sat
• Building swells Sun but choppy with fresh onshore winds
• Good S/SE swell Mon with fresh S'ly winds, ideal for protected spots
• Back to an extended run of very small conditions for the majority of next week
• Chance for a new swell next weekend of thereabouts

Recap

Tiny waves for the last few days.

This weekend (Oct 23 - 24)

Not a great outlook this weekend.

With no regional swell on offer today, and no new energy expected on Saturday, we’re looking at a continuation of unsurfable conditions across the South Arm. A weak front crossing the coast will swing winds to the SW, and they’ll gradually freshen.

A new low forming east of Tasmania on Sunday will strengthen S/SW winds from late Saturday onwards, and this will build a local windswell on addition to some long range groundswell, generated by a powerful though distant Southern Ocean low earlier this week. 

The large travel distance (of the groundswell) will have a significant impact on size and consistency, which might reach an occasional 2ft across open South Arm beaches, but the local windswell has the potential to increase this size by another foot or two as the day progresses.

However with the accompanying winds being strong to gale force S’ly, only sheltered locations will offer workable conditions (and they may be a little on the small side - though the direction will be unusually favourable from the S/SE). 

So, keep your expectations low on Sunday and you should pick up a few small runners into the afternoon as the swell reaches a peak. 

Next week (Oct 25 onwards)

Monday’s probably your best chance for a wave from this low off the East Coast. Although the core of the low will be positioned off NE Tasmania, with the strongest winds just outside the South Arm’s swell window, the fetch will reach maturity overnight Sunday and it’ll also extend a reasonable distance to the south (see the split below). 

So, we should see an appreciable level of sideband S/SE energy on Monday before the low weakens and clears to the east. Exposed South Arm beaches should see choppy 3-5ft sets and protected locations are looking at nice small waves under fresh, though easing S’ly winds.

Note: the swell direction will be from a less frequent direction (S/SE) so this will create a difference response in wave heights at many beaches, compared to what you’re used to seeing. You’ll need to put in some legwork to find the best waves. 

Wave heights will then rapidly ease into Tuesday and winds will become light as a high pressure system moves in from the west. 

The rest of the week looks very small and uninteresting, thanks to an upstream blocking pattern, in the form of a cut-off low developing south of Western Australia overnight Monday. This low will intensify and slips southwards (not a great trajectory, to be honest). However, these systems are usually swept up by the polar westerly flow, and often slingshot a polar front or two through our swell window as it migrates towards New Zealand. This should provide the potential for a flush of fresh S/SW swell later next week and into the following weekend. 

More on this on Monday. Have a great weekend!