The fetch out of Cook Strait, extending up past Taranaki Peninsula and into the Tasman sea looked good on ASCAT (satellite windspeed) passes through Wed/Thurs, with areas of storm force winds embedded in a long fetch of severe gales to low end gales. With the buoys and observations already confirming the swell it’s only local winds we’ll be concerned with.
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The good news for our surf prospects is a complex low pressure system located just NE of the North Island is strong enough and large enough to generate severe gales to low end storm force SE/ESE winds out of Cook Strait, adjacent to the Taranaki peninsula and extending out into the Eastern Tasman sea.
A large (1025 hPa) high pressure system is currently drifting over Central NSW into the Tasman sea and this high pressure cell is expected to track SE, strengthen and become slow moving as it meanders near the South Island for most of this week. That creates a summer-style synoptic pattern, with SE/ESE Tradewinds through the sub-tropics and a N’ly flow through temperate NSW.
In addition to S swell there’s quite a strong high pressure surge of SE winds developing over the weekend. This surge of 20-30knot SE winds is likely to push wave heights up into the 3ft+ range, especially in SEQLD, through Sun.
Eventually the low pressure system tracks into the Tasman, and with an associated front forms a low in the active window E of Tasmania overnight Fri/early Saturday. That will see some new S swell arriving on the weekend.
The current synoptic pattern is a low pressure system E of Tasmania directing a fetch of SSW to S strong winds to low end gales adjacent to the NSW South Coast. This low then eases as it moves out into the Tasman sea later today.
The current Tasman low has drifted out and become absorbed into a long, NE/SW angled trough in the South Pacific, which is currently organising and energising a broad but thin fetch of E’ly gales from the South Pacific down into the Tasman Sea adjacent to the North Island.
These swell trains are generated as a deep, angled trough through the area between the North Island and New Caledonia merges with the remnants of the Tasman low and focusses E to ENE winds in a broad area near the North Island during Friday.
From tomorrow we see a large, southwards located high and multiple troughs located in the Tasman sea and inland become the dominant synoptic features for the week. This is going to set-up some tricky, short-lived fetches as well as another week of multiple wind changes.
Very dynamic, unstable week ahead that has a very La Nina looking signature to it. Primarily the strong, southwards located high and a very troughy pattern in the Tasman sea, that has good swell potential for the region.