South Arm Surf Forecast by Ben Matson (issued Wednesday 12th May)

Features of the Forecast (tl;dr)

• Extended spell of very windy conditions
• Very small surf for the next 4 days
• Large swell Mon, easing Tues
• Next decent swell due around Fri next week though likely wind affected

Recap

Lumpy waves early Tuesday improved into the afternoon as winds eased and became light and variable. We’ve seen small clean leftovers today with 1-2ft sets and offshore winds. 

This week (May 13 - 14)

*Today’s Forecaster Notes will be brief as Craig is away*

Check the forecast graph - we’ve got ten consecutive days of windy conditions coming up, initially related to an amplifying Long Wave Trough steering a succession of vigorous cold fronts across the state, which will then be (next week) followed by more fronts of a polar origin. 

Unfortunately, the storm track is very westerly right now - aimed north of Tasmania latitudes (see below) - which means we’ll see very little size penetrate into Storm Bay.

As such, expect tiny clean conditions on Thursday morning with strengthening N’ly tending N/NW winds, ahead of a late gale to storm force W’ly change. Winds will then hold gusty W/SW on Friday, with only a minor increase in size - and with these conditions it won’t be worthwhile.

This weekend (May 15 - 16)

It’s not looking very good this weekend.

Fresh, gusty SW winds early Saturday will swing back to the west and strength into the afternoon and throughout Sunday as the main front in this sequence approaches from the south-west that evening.

Again, thanks to a poorly aligned storm track throughout the end of the week, I’m not expecting much size in the South Arm, so keep your expectations low.

Next week (May 17 onwards)

Storm force winds are likely late Sunday and maybe early Monday, and so we’ll start the week with SW gales that’ll ease gradually through the day. 

More importantly, Sunday's late front will have begun intensification south of SA, which is much closer to Tasmania and thus better positioned inside our swell window (see below). Additionally, with thanks to its polar origins, it'll generate a S/SW swell that’ll efficiently push into Storm Bay. Exposed spots should push 5-6ft and there’ll be good runners on the points, albeit quite a bit smaller. 

Slowly easing size through Tuesday will be accompanied by a strengthening W’ly winds as another series of fronts approach the state. However the storm track will be back to a more zonal flow in our W/SW swell window which will impact surf size in the South Arm - but not as much as the next four days. 

Most of next week should see wind affected surf in the 2-3ft range under sustained gales from the western quadrant, with a peak in size pushing 4ft around Friday. More on this in Friday’s update.