The Tasman Sea, by contrast, is looking very mellow with a weak high pressure cell over NSW and a few decaying remnants of the long lasting Tasman Low sitting near New Zealand. Those weak pressure gradients across our main S-SE swell window will lead to a very quiet week swell wise, with mostly offshore winds.

995 hPa low still sitting in the Central Tasman, but the supporting high pressure cell has slipped in underneath the low and as a result we’re seeing a slowly diminishing fetch and easing pressure gradients both in the Tasman and along the coastal fringe.

A secondary front pushing into the Tasman coalesces with a deepening low near New Zealand and the system then retrogrades back into the Tasman over an already active sea state delivering powerful S/SE swell before taking up residency in the Central Tasman for a few days next week with a slow, slow easing in big swells expected.

The main synoptic activity this week will be related to an amplifying node of the Long Wave Trough which is expected to slide through the Tasman Sea before parking itself across New Zealand longitudes later in the week. We’ll see a prolonged round of large to very large swell as a result.