South Arm Surf Forecast by Ben Matson (issued Friday 7th May)

Features of the Forecast (tl;dr)

• Small, windy surf Saturday
• New swell Sunday with improving conditions
• Gusty onshores Mon with building surf, best Tues with easing wind and surf size
• Next round of swell due Fri/Sat/Sun next week

Recap

Clean conditions and fun surf with inconsistent surf in the 2-3ft range. 

This weekend (May 8 - 9)

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

Smaller surf on Saturday and freshening westerly winds will create less than ideal conditions across the South Arm. It’s not worth getting too excited about.

A new swell is due on Sunday, though I’m a little hesitant as to how much size we’ll see as the storm track has been a little weaker than initial model guidance suggested earlier in the week . Somewhere between 2ft and maybe 2-3ft seems a reasonable ballpark but confidence isn’t high. Winds will veer NW and freshen so conditions should be clean. 

Next week (May 10 onwards)

The models have wiped the cut-off low in the Bight for early next week.

Instead, we’re looking at a series of fronts at about 40-45S (Tasmanian latitudes) over the weekend, travelling rapidly east - but this is a poor alignment for the South Arm so we won’t see much size from it.

However, a polar low developing off the ice shelf on Sunday (well below SA) is better positioned for a swell increase across the South Arm. It’ll clip the coast on Monday delivering W/SW tending SW gales, building surf size to a bumpy 3-4ft through the afternoon (smaller earlier). Tuesday looks much better with easing winds that could very well swing light W/NW early morning, and easing size from 3ft+ to 2-3ft. There is a chance that it'll remain onshore though, I'll have a better idea on Monday.

We’ll then be back to smaller residual swells on Wednesday with light winds swinging to the north and freshening into Thursday as size bottoms out.

A windy period is then expected from Friday onwards thanks to an amplifying node of the Long Wave Trough SW of West Oz early in the week, which will move under the continent by mid week (see below). It’ll be best aimed into the SA and Vic coasts but we’ll see some small waves across the South Am into next weekend. 

Have a great weekend, see you Monday!