Southern Tasmanian Forecast by Steve Shearer (issued Mon July 21st)

Features of the Forecast (tl;dr)

• Large NE'ly windswell building Tues AM, peaking Tues PM with N tending NW winds
• Clean easing NE windswell Wed
• Small NE windswell persists through next week
• Another round of large NE windswell Sat easing Sun with fresh N’lies tending NW Sun
• Small surf into mid next week
• Small S pulses medium term

Recap

A small pulse of E/SE swell Sat saw some 2ft sets under gusty NW winds with size evaporating into Sun under fresh NW tending W winds. Small to start today but as N’ly winds increase we are seeing some NE windswell building through the a’noon.

This week and next week (Jul 21 - Aug1)

We’ve got a high in the Tasman and a low pressure north of the North Island as we start the new week. We’ll see N’ly winds increase short term and then as we head into the weekend in response to an approaching cut-off low in the Bight, with sizey pulses of NE windswell on the radar for these periods. Other than that, nothing significant medium term as we start the week. 

In the short run we’ll see NE windswell continue to build through tomorrow under strong N’ly winds. Size to 4-6ft builds further to 6-8ft through the day.

Size eases rapidly through Wed but the morning looks great with 4-5ft of swell under offshore W’ly winds, easing quickly through the day. 

A couple of days of small leftovers to 1-2ft or less follows with offshore W-W/SW winds Thurs, trending more W/NW on Fri. There should be a rideable wave for longboards both days. 

We’ll see N’lies ramp right up Sat as a low approaches from the west with another strong episode of NE windswell. Size should build from 4-5ft into the 6ft+ range with some bigger 8ft sets possible under fresh N’lies.

That NE windswell eases Sun as the low shunts the fetch away eastwards and brings an offshore flow. N’ly winds will shift N/NW  to NW’ly through the day and we’ll surf ease from 6ft to 3ft through the day with plenty of good waves around.

Not much expected to start the new week. The low is expected to stall near Tasmania, and with high pressure right up in the sub-tropics we’ll see a stiff W’ly-W/NW’ly flow through Mon and possibly into Tues with easing surf Mon becoming tiny Tues.

S swells should resume from mid-week, either as a result of fronts pushing proximate to the NSW coast or the low developing a fetch SE of Tasmania- models are offering divergence outputs there.

Nothing too sizey at this stage, although longer term GFS has a monster low under the continent as we head into August, better positioned for the southern states but still offering possibility of S’ly groundswell wrap for the Eastern seaboard.

We’ll see how it looks on Wed.