Eastern Tasmanian forecast by Steve Shearer (issued Wed April 16th)

Features of the Forecast (tl;dr)

• Easing but still fun E'ly swell Thu with N/NW winds
• Large E’ly swell now expected to build Good Friday from low in Tasman with light NW tending N’ly winds
• Still pumping Sat with light NW-N winds
• Easing surf Sun
• Small S swells next week

Recap

Small fun E-E/NE swells to 2-3ft yesterday and into today with winds shifting mod N'ly. 

This week and next week (Apr 16 - 25)

A complex scenario which is atmospheric lead-up work for a major swell generating pattern is now underway. A tropical depression between Vanuatu and New Caledonia has formed a tropical cyclone (TC Tam) and is racing south-eastwards at 23kts, where it is expected to merge with another tropical low SW of New Caledonia. After a binary interaction between the two systems, the merged low transitions into a storm force sub-tropical low which tracks SW into the Northern Tasman. This storm force low has a broad fetch aimed directly at the East Coast down to Tasmania, generating a large E’ly quadrant swell for Good Friday and the Easter weekend with uncommonly large swell periods for swells from that direction. Easing pressure gradients across the East Coast during the swells arrival and peak look to supply good surface conditions. 

In the short run we’ll see more small, fun E’ly swells in the 2 occ. 3ft range with light N’ly tending variable winds.

We’ll see some N’ly quarter wind for Good Friday initially NW at mod paces before it trends N’ly through the day. A very large E’ly swell in the 12-14 second period band- uncommon although we just saw one from the last monster Tasman low- will be in the water and still building Fri morning. With the low in Tasman Sea proximity there’ll be a range of swell trains in the water, in the 6-8ft range with some larger rogue sets likely in the mix, up in the 10ft range. It’s going to be very large, with lots of water moving and with the E’ly direction, widespread across most breaks. Experienced surfers only. 

Similar size into Sat morning with large 6-8ft surf and 10ft sets on offer. Conditions should be primo under offshore W’ly winds, which will tend to light N’lies as a cut-off low approaches from the west. 

Much more user friendly for Sun morning as swells tail off and tend more SE. Still holding in the 4-5ft range early dropping back to 2ft with the occ. 3ft set in the a’noon. With a front and cut-off low approaching from the west we’ll see early NW winds tend N-NE through the a’noon, reaching mod paces by mid-late a’noon.

Monday is still looking pretty tricky to call as the cut-off low pushes off the coast of southern/Central NSW. Depending on the positioning we could see offshore winds and some small fun leftovers or onshore winds and building S through SE swells. We’ll likely art least see a window of light winds and small leftovers for the early.

Surf potential into next week will be determined by this small low moving offshore from the coast. 

We may also see another low working it’s way through the South Pacific slot, although at much more distant longitudes than the current system (see below). GFS has a more bullish outlook suggesting some nice E’ly swell late next week in the 3-4ft range while EC is barely interested, with a weak low only showing signs of life once it’s moved behind the North Island. 

We’ll flag it for and see how it looks Fri.

In the mean-time much bigger fish to fry in the short-term.

Seeya on Good Friday!