Eastern Tasmanian Forecast by Steve Shearer (issued Mon August 26th)

Features of the Forecast (tl;dr)

• Building N swell  Tue with strong to near gale-force N/NW winds, slowly easing Wed with strong NW tending W/NW winds
• More small NE windswell Fri and into the weekend from gales out of Bass Strait
• Gusty NW winds continue all week, with W’ly periods
• Possible S swells early next week with winds continuing from the W

Recap

Small levels of NE windswell Sat were in the 1-2ft range, a notch bigger Sun in the 2ft range and have eased back to 1-2ft today under W winds tending NW and freshening as a front passes over the state. 

This week and next week (Aug 26 - Sep 6)

It’s not a great pattern for the East Coast Tasmania with most of the swell generating winds under the continent and favouring South Oz and Vicco. The pattern of strong, zonal W’lies tied to polar lows and embedded cold fronts and weak mobile high pressure won’t offer much for NETas but we will see some small NE swells generated by radial spread from gales out of Bass Strait this week.

In the short run we’ll see fresh to strong NW winds tomorrow and NE wind swells to 2ft building to 3ft during the a’noon. Winds do tend a little more pre-frontal NW’ly o/night Tues into Wed and this should see NE windswell build to 2-3ft on Wed under strong to low end gale force NW winds tending W’ly during the day.

Radial spread from gales out of Bass Strait sees N'ly windswell Tues/Wed

That swell should ease and surf go tiny later Wed into Thurs.

The next increase in NE winsdswell should come on Fri as winds tend NW-N again in Bass Strait and generate radial spread for NE Tas. Expect size to 3ft early, easing during the day with strong N/NW winds tending NW then W/NW through the day.

Source of NE windswell for Fri

Into the weekend and more of the same with strong zonal fronts bringing gusty to gale force W-NW winds. We’ll see more small NE windswell from radial spread from these fetches, at this stage with size to 2-3ft looking likely both days. We’ll fine tune this through the week. 

Next week starts off with more zonal fronts but there is some model divergence. We have some model divergence early next week with ECMWF suggesting a more energetic outlook as fronts penetrate deeper into the Tasman with a NE movement and better aligned winds in the fetch.

That would suggest moderate S swells through Tues  possibly Wed.
GFS maintains a more zonal flow next week (see below), with more minor S swells on offer from Tues.

Nothing major from from any of the models through next week so we’ll pencil in S swells and NW winds and see how it looks as we move through the week.

Seeya Wed.