A classic Summer blocking pattern is now setting up, with a slow moving high drifting well south of Victoria and a series of troughs interacting with a strong high pressure ridge which has reached Central NSW and is now building into more sub-tropical regions.
A trough brings a S’ly change tomorrow , with another strong high tracking south of the Bight poised to be the main weather feature this week.
TC Cody is the main game in town and the system has now undergone extra-tropical transition and is classified as a storm force sub-tropical low.
Current ASCAT (satellite windspeed) passes show a healthy fetch of E’ly winds flanking a tropical low as drifts south of the area between Fiji and New Caledonia towards the North Island.
Our current synoptic pattern is typical of the season and the La Nina end of the ENSO cycle. High pressure straddles New Zealand and a tropical low now is drifting south from between Fiji and Vanuatu towards the North Island.
By Thurs the wave climate will come under the influence once more of the tropics, with a broad Tradewinds band being accelerated by a tropical low drifting South from area between Fiji and Vanuatu.
A strong high is now slipping in underneath Tasmania and the combination of the decaying ex cyclone, developing high pressure ridge and an interior trough is creating a long, broad fetch E/NE winds extending from New Caledonia down into the Central Tasman Sea.
Swell from ex TC Seth, which transitioned into a gale force sub-tropical low Sun is the major synoptic feature this week, responsible for both swell production and directing gradient winds as it slowly weakens and meanders close to the NENSW/SEQLD coast for the next few days.
While there is still a bit of model variance the broad scale pattern is clear enough to make a high confidence call on Mon seeing a significant pulse of E/NE groundswell across the region.
Surf prospects from this low are now upgraded to excellent with major weather models expecting the system to track parallel to the East Coast on a Southerly path, possibly reforming as a significant extra-tropical storm in the lower Tasman Sea next week.