Eastern Tasmanian forecast by Steve Shearer (issued Mon Mar 10th)

Features of the Forecast (tl;dr)

• S’ly change Mon with trough and building S swell into Tues
• NE windswell Wed, clean leftovers easing quickly on Thurs
• Tiny surf Fri/Sat
• S groundswell Sun
• Strong S swell spike Mon, easing during the day
• More S groundswell likely Wed/Thurs

Recap

Fun waves over the weekend with E/NE swell to 3ft Sat, with NE windswell adding more energy later Sat into Sun. The NE windswell has remained persistent into today as NE winds remained in the swell window overnight. Size to 3-4ft today was brushed by offshore winds before N’lies kicked up with a gusty S’ly change expected later today. 

This week and next week (Mar10- Mar21)

We’ve got a large high in the Tasman, feeding moisture into the remnants of ex TC Alfred, which is blending into the monsoon trough over Northern Australia. The whole synoptic pattern on the East Coast in the wake of Alfred is a moist onshore flow which looks to persist through into the mid week. A weak front races across the lower Tasman today before reinforcing high pressure slips into the Tasman to reset the flow, albeit at a weaker level.

In the short run todays front brings a spike in S swell through Tues with size to 3-4ft early and winds from the SE initially , tending E’ly as high pressure slips under the state.  Swell will ease off quickly through the a’noon. 

We’ll see winds shift NE to N/NE’ly and freshen on Wed as high pressure moves into the Tasman. That should generate some workable NE windswell to 2-3ft in the a’noon.

Get in early Thurs for clean leftovers to 2ft as a trough brings offshore winds, tending NE in the a’noon. Surf will quickly ease to tiny/flat through the day. 

Surf remains tiny into Fri and then Sat under mostly offshore winds as fronts pass to the south. 

By Sun we should see a little more action as long period S swell wrap from one of the deep polar lows supplies 2ft sets to S exposed breaks under fresh W-W/NW winds. 

Action from the south is on the radar for next week, after an extended period of tropical action dies down. First cab off the rank is a frontal system and trough which looks to push across Tas later Sun into the Tasman o/night into Mon (see below) and bringing a stiff S/SW- S’ly flow Mon.

Models are still divergent over the strength of the front with the more bullish GFS outlook suggesting surf building into the 4-5ft range o/night into Mon and easing through the day. Expect revisions on that though the week.

Further ahead and long period S groundswell from another of the deep, storm force lows passing under the continent (see below) looks to make a glancing blow later Wed into Thurs. 

We’ll pencil in S facing beaches to reach 3-4ft with outliers likely at deepwater adjacent reefs which can maximise long period S swells. 

A trough of low pressure may also form in the Tasman late next week or into the weekend with potential for S-SE swell next weekend. 

Too far off to have any confidence in specifics so check back Wed and we’ll continue to dial it in as we get closer to the event.
Seeya Wed.