The broad pattern will be setting up by Boxing Day with a dominant, slow moving high in the Tasman and low pressure expected to form along the monsoon trough line in the Coral Sea and in the South Pacific near the North Island. That will see at least dual swell producing fetches aimed at the Eastern Seaboard, favouring our subtropical region for most size.

The combination of a Tasman low and strong high moving through the Bight has supplied a stack of S swell to the f/cast region since late last week, with an intensification and N’ward movement of the low upping the size and local winds through today on the MNC, and across the rest of the region through tomorrow. Pressure gradients will now slowly ease as the low starts to dissipate and the strong high weakens as it moves South of Tasmania through tomorrow.

The main synoptic feature for the short term period is a developing complex Tasman Low that'll spin up east of Bass Strait overnight, and reach peak intensity on Friday, but actually remain active within our swell window until next Wednesday.

A deepening Tasman Low is currently parked midway between Tasmania and New Zealand, and southerly gales around its western flank reached maximum strength around lunchtime today.