South Arm Forecast by Ben Matson (issued Wednesday November 6th)

Features of the Forecast (tl;dr)

• Very small waves for the rest of the week
• Fun swell increase for the weekend with ideal winds, good surf at exposed beaches
• Better groundswell for Monday, with good winds
• Size easing Tuesday but holding steady Wed/Thurs with fun small waves most days

Recap

Small waves over the weekend have become tiny to flat since Tuesday. Winds have been up from the NE for the last few days. 

This week (Nov 7 - 8)

Model data is showing a small pulse for Thursday though I’m not confident on the source. The leading edge reached Cape Sorell this afternoon however it was generated quite a fair way back in our swell window, and does have a lot of west in its direction, so the best we can hope for is small sets around the 1ft mark.

As for conditions, regionally we’ll see fresh westerly breezes but inside Storm Bay is likely to see variable winds (early offshore, afternoon SE sea breezes).

A front will cross the coast on Friday afternoon, swinging freshening N’ly winds around to a gusty W’ly during the day. With only small residual surf on offer it’s not worth getting too excited about.

This weekend (Nov 9 - 10)

The charts look very promising for the weekend, with Friday’s vigorous front expected to have a solid long period swell trailing behind, that will provide large waves to the SA and Vic coasts.

However, the early stages of this system will have been aimed slightly north of our swell window, so the initial swell increase on Saturday and Sunday will probably be a little too west to offer any significant size.

Conditions should be clean both days with local topographical effects creating light to moderate NW winds despite the presence of westerly gales just south of the state.

As for size, Saturday will start off small but should build to 2ft+ into the afternoon, and size should hold in this range for Sunday, maybe a little bigger (occ 3ft sets).

So, expect fun clean waves at the exposed beachies both days, with perhaps a lag early Saturday morning.

Next week (Nov 11 onwards)

Model guidance suggests surf size will ease through Monday, but I feel that this is when we’ll see another round of swell push into the South Arm.

The parent low related to Friday’s change will undergo secondary intensification well to the SW of the state on Saturday (see below), with storm force SW winds just off the ice shelf generating a strong SW thru S/SW swell that will push through overnight Sunday and provide quality 3ft+ waves throughout the South Arm on Monday.

By this time, winds should be around to the NW as an unrelated front approached from the west, so conditions will be clean. Monday’s looking really good at this stage.

Easing size on Tuesday will be accompanied by similarly favourable winds as a sequence of poorly aligned fronts slip below the state. They’ll provide indirect swell energy into Storm Bay that should maintain 2ft+ sets through the rest of the week. 

The long term outlook is also promising.

Another strong Southern Ocean low is now expected to move through our swell window early next week, setting up a strong swell for Thursday or Friday, of which the closer proximity of this system to Tasmania should allow for more south in the swell direction and thus more size throughout the South Arm. 

I’ll have more on that in Friday’s update.