Eastern Tasmanian Forecast by Steve Shearer (issued Mon Nov 11th)

Features of the Forecast (tl;dr)

• Small E/NE-NE swells Tues peaking Wed
• Small S swell flush Thurs
• Building NE windswell Sat PM, becoming very sizey Sun AM before easing
• NE windswell leftovers on Mon with SW winds
• Small S swell likely Tues/Wed
• Possibly sizier S swell later next week, check back Wed for updates

Recap 

Tiny/flat surf Sat with Sun seeing S’ly groundswell to 2ft showing up late in the day. Still some S groundswell to 2ft with light winds tending N’ly.

This week and next week (Nov11- Nov22)

Another unstable, troughy week ahead with humid, unstable air over the continent creating a series of troughs, one of which forms a slow moving trough of low pressure off the Mid North Coast which interacts with a weak high pressure cell drifting in the Tasman. That will supply some workable E/NE quadrant swell along with more local E swell.  A decaying front looks to bring a shallow change Wed before another high moves into the Tasman over the weekend. The troughy pattern looks persistent into next week so expect lots of wind changes and constant revisions as models struggle to resolve the dynamic and unstable atmosphere. 

In the short run we’ll see winds tend light/variable before an E-NE seabreeze in the a’noon. Tiny surf to start with a minor increase in NE windswell to 1-2ft in the a’noon.

NE windswell then bumps up a notch into Wed with size to 2-3ft with light N’lies, then W’ly before a trough brings a S’ly change. 

We may see some low quality short period S swell on Thurs to 2-3ft with S’ly winds tending SE-E in the a’noon as a high approaches the state.

That high then moves over the Island on Fri with light winds shifting NE in the a’noon and small windswells to 1-2ft tops.

Into the weekend it looks muscular with the high moving E and a stiff proximate N’ly fetch developing along the NSW Central Coast down to Bass Strait as an inland trough and cut-off low approach from the West. Local N’lies will really whip up through the day with N tending NE winds expected to reach 30 knots. Under current modelling we’d expect an increase through the day in NE windswell, up into the 4-6ft range from mid arvo until close of play.

Sunday gets even bigger as the fetch really ramps and extends south of Tasmania, (see below) producing siozey NE windswells to 6-8ft with bigger sets.

Source of sizey NE windswell Sun AM

Fresh N’ly winds tend NW and then SW as a trough pushes up the Island. Sunday looks very solid early, easing through the a’noon.

Into next week and A sharp trough and front push through Sun and bring a SW’ly change. NE windswell holds to 3-4ft early Mon before easing during the day. 

Confidence in specifics takes a nose dive from there as the trough lingers in the Tasman, possibly forming another trough of low pressure as a front moves through Tues/Wed.

We should see some kind of S swell generated by the trough and front Tues or Wed. A stronger S swell may be on the cards following that depending on how the trough responds to the front. 

A trough in the South Pacific may see a fetch near the North Island early next week which may see some E-E/NE swell mid next week. Models are divergent so lets flag it for now and see how it looks on Wed.

Seeya then.