Eastern Tasmanian Forecast by Steve Shearer (issued Wed Dec 4th)

Features of the Forecast (tl;dr)

• Small NE swells Thurs with light NW winds tending N’ly
• Slight bump in NE windswell Fri with N’ly winds tending variable in the a’noon
• Small bump in S swell Sun
• Surf easing Mon 
• Small swells next week, possible bump in S swell Thurs/Fri

Recap 

Swells from the E/NE-NE have hung in there above f/cast expectation with 2-3ft surf yesterday under light winds, easing a notch today into the 2ft range. Conditions were clean early under W-NW breezes before mod/fresh N’ly winds kicked up. 

This week and next week (Dec4- Dec13)

A long tradewind fetch and more local NE fetch anchored by a 1024hPa high in the central SW Pacific is slowly retreating eastwards with a weak high cell expected to migrate into the Tasman overnight and tomorrow in the wake of a shallow trough now moving up the NSW Coast and expected to stall and wash out around the lower reaches of the MNC. Some decaying and fast moving frontal activity in the lower Tasman is currently scooting across that sea. Once the new high sets up shop in the Tasman we’ll see the N-NE flow which has been a constant for a month reset until a front brings a W’ly change on the weekend. No major swells ahead as the pattern of weak, mobile high pressure continues but there’ll be some windows of opportunity with small NE windswell and minor flushes of S swell. Details below. 

In the short run there’s not much happening with small E/NE swell leftovers to 1-2ft under light NW winds tending mod N’ly in the a’noon as new high pressure moves NE of the Island.

We’ll see the NE flow proximate to the island increase into Fri, bringing a small boost in NE swell to 2ft or so. Light NW-N winds tend N’ly then variable as a trough moves into Bass Strait.

Into the weekend and variable winds Sat tend gusty NW’ly as the trough gets shunted eastwards by a vigorous front.  We won’t see the full strength of the front until o/night Sat and into Sun so conditions should be workable Sat with small surf from the NE-E/NE to 2ft on the sets.

The frontal passage sees gusty W’ly winds Sun with a small signal of E/NE swell to 1-2ft in the morning and some new S swell to 2ft in the a’noon. 

Front brings some small S swell on Sun

As stated on Mon, the following high moves quickly into the Tasman in the new week, moving NE and weakening.

Back to W’ly flow Tues as a front passes under the state with easing S swells and small surf into Wed. 

There’s reasonable model agreement on a trough of low pressure forming in the Tasman mid next week but poor run to run consistency so expect some major revisions. We may see a flush of S swell develop Thurs into Fri as winds on the SW flank of the trough generate S swell. We’ll pencil in 2-3ft for now and see how it looks Fri. Following that more weak, mobile high pressure suggests a rapid return to small NE windswells with a broad but weak tradewind fetch putting a floor under wave heights with a background signal to 2ft. We’ll revisit that scenario on Fri. 

Seeya then.