Eastern Tasmanian Forecast by Steve Shearer (issued Wed Dec 18th)

Features of the Forecast (tl;dr)

• SE-E/SE swells holding over the weekend at small, fun levels
• Low forming off NSW South Coast Mon with sizey S swell developing, peaking Tues, easing quickly Xmas Day
• Sizey NE swells developing into Fri morning, easing quickly as offshore winds develop

Recap  

NE windswell in the 3-4ft range cleaned up nicely under offshore winds before easing quickly late in the day. Nothing much leftover this morning with 1-1.5ft of tiny E/NE swell under SW-S winds on offer. 

This weekend and next week (Dec20- Dec28)

Still looking good for Sat. Current ASCAT (satellite windspeed) pass shows a Tasman low with a long fetch of strong S-S/SE winds and a board fetch of SE winds extending under the South Island. Concurrently, weak high pressure is moving NE to be off the sub-tropical coast o/night and into tomorrow morning with a weak trough/front pushing past Tasmania tomorrow. 

That will see early N’ly winds before a S’ly change in the morning. Surf in the 2-3ft range builds to 3ft+ from the E/SE-SE. 

By Sun we’ll see size ease back a notch to 2-3ft with light/variable winds tending N/NW to N’ly in the a’noon. 

We are getting good model agreement on the Xmas week now, leading to increasing confidence on outcomes. O/night Sun into Mon we’ll see a low form off the Gippsland Coast and begin to deepen rapidly through the morning. An early W’ly flow tends SW and begins to freshen by start of business hours.  A modest increase in new short range S swell should build to 3-4ft through the a’noon. 

By Xmas Eve we are expecting a deep ( approx. 980 hPa) cut-off low in the Tasman, due east of Tasmania (see below). A steeply angled due S swell will be in the water with a mod SW-S flow. It won’t be giant but we will see sizey, energetic S swells to 3-5ft at S exposed breaks, with a mod SW tending light/variable flow.

Current modelling has the low slow moving through Xmas Eve but rotating away from Tas with surf from the S/SE easing to 2-3ft then 2ft or less on Xmas Day.
Tiny surf is expected Boxing Day.

An approaching cut-off low sees NE winds freshen into Fri with a corresponding increase in NE windswell expected. We should see N/NE winds freshen o/night Thurs and tend N’ly with NE windswells building to 6ft into Fri morning before easing rapidly as a low moves south of the Island bringing fresh W’ly winds. There should be some good/great waves once the offshore wind kicks in.

\Easing swells then over next weekend, as the cut-off low gets shunted southwards and high pressure moves into the Tasman. Looks like a quiet run into the New Year from there.

We’ll see how that all looks on Mon. 

Seeya then and have a great weekend!