A week of strong westerlies and southerlies
The coming days are shaped by an unsettled westerly flow. A low is crossing central New Zealand overnight, driving fronts north through the country. Southwesterlies follow, with embedded fronts making for a messy start to the week. By Tuesday, another front moves up the South Island before a ridge of high pressure settles things mid-week. The ridge will briefly favour the North Island, while fresh northwesterlies return to the South.
Where to avoid: gale warnings aplenty
The headline is simple: Sunday through Tuesday is a time to be cautious. Gale warnings stretch across most coasts, with winds rising above 35 knots and swells up to five metres in places.
- Northland and Kaipara: Heavy westerly swells of 5m and sustained gales make this one of the roughest areas through Monday. Squally thunderstorms are possible.
- Raglan and the West Coast: Conditions mirror the north, with 35-knot southwesterlies and huge swells. These seas will be dangerous for small craft.
- Cook Strait and Castlepoint: Strong northwesterlies flip to southerlies, reaching 40 knots at times on Monday and Tuesday. Visibility will be poor in squalls.
- Southern coasts (Milford, Puysegur, Foveaux, Chalmers): A series of fronts hammer these waters with gales, rain squalls, and swells up to 5m. Puysegur and Milford are particularly volatile with multiple wind shifts.
Better prospects: timing is everything
There are some safe windows, but picking your spot matters.
- Abel Tasman and Tasman Bay: After Sunday’s shifts, Monday and Tuesday look manageable with easing westerlies and improving visibility. By Wednesday, a light northerly offers the best local boating window.
- Marlborough Sounds: Sheltered waters here should see some respite. While Cook Strait remains treacherous, the inner Sounds will settle once the ridge arrives mid-week.
- Eastern Bay of Plenty and Coromandel: While Sunday and Monday are poor with gale warnings, Wednesday looks much better with variable light winds and easing seas.
- Chatham Islands: Conditions remain changeable, but Wednesday brings moderating seas as swells ease from heavy to moderate.
Mid-week outlook: calmer but short-lived
By Wednesday, high pressure finally edges over the North Island. Variable light winds develop for many coastal areas, offering a brief break from the gales. For boaties looking for a safe trip, Wednesday is the day to circle in the diary. However, the South Island will already feel the push of fresh northwesterlies ahead of the next front.
Final word for boaties
The early week picture is dominated by gale warnings and heavy seas — far from ideal for small craft. The best bet is to sit tight until Wednesday, when calmer conditions briefly return, particularly around Abel Tasman, the Sounds, and Bay of Plenty. Even then, keep an eye on the next front rolling in from the Tasman.
In short: if you can wait, Wednesday is your window in some places. Otherwise, give the wild westerlies a wide berth.
