Southern Tasmania Forecast (issued Wednesday 19th February)
Best Days: Saturday morning, Sundaym early Monday, Tuesday, early Thursday, Friday
A small increase in swell was seen through yesterday, probably emanating from an infeed of SE gales wrapping around a deepening low pressure system just to our south.
This low produced a fetch of gale to storm-force S'ly winds just out of the South Arm's swell window, but as the system moved across us overnight, a fetch of weaker SW gales were aimed in out swell window, generating today's SW groundswell to 3-4ft with onshore winds. There would have been smaller levels of S/SE swell in the water too off the SE winds wrapping around the bottom of the low (pictured below).
This weekend and Monday (Feb 22 - 24)
There won't be much swell leftover from the low tomorrow morning but a strong increase in SW groundswell is due during the afternoon ahead of a peak Sunday and then secondary pulse Monday.
This will be related to a couple of back to back polar fronts firing up towards us from today through until Sunday. Today and this evening's system (pictured right) will be the strongest generating a good 3ft+ of SW groundswell for Sunday, but the secondary system will be acting on an already active sea state produced by this initial system, generating another 3ft+ or so swell for Monday.
Winds tomorrow afternoon will be onshore from the W/SW after an early morning W/NW'ly, while Sunday looks great with NW tending W/NW winds. Monday looks a little dicey with a weak change due during the morning, but at dawn we should still see a W/NW'ly.
Tuesday onwards (Feb 25 onwards)
Monday's swell will drop away through Tuesday and Wednesday under favourable winds, but heading into the end of next week another good pulse of SW groundswell is due across the region.
This will be related to the Long Wave Trough focussing a couple of polar fronts up towards and over us next week, generating a good 3ft+ of swell for Thursday but with less favourable winds. We'll review this on Monday though.