The forecaster said there is also a high confidence of warning-level rain for the ranges of Hawke’s Bay as the system tracks south across the North Island.
Cyclone Vaianu is currently a Category 3 system in the tropics, but is expected to weaken to Category 1 or 2 strength as it approaches New Zealand, and is forecast to move gradually south to southeast as it crosses the North Island on Sunday.
MetService’s outlook suggests there is moderate confidence of severe gales affecting central areas, including Hawke’s Bay, early on Monday even as the system moves away.
Meteorologist Braydon White said on Wednesday although the exact track of the cyclone remained uncertain, some level of impact for Hawke’s Bay was “likely”.
“It’s a bit too early to say exactly what it could mean for Hawke’s Bay, but it looks quite likely that they will get some significantly strong winds and heavy rain.”
He said the severity would depend on the cyclone’s path: a more easterly track would likely reduce the impact, while a more central track could bring more damaging conditions.
White said the system was expected to affect the whole region, and coastal areas were also at risk.
Low pressure at the centre of the system, combined with strong winds, could lead to large waves and energetic swell, increasing the risk of coastal inundation, erosion and flooding.
Hawke’s Bay Regional Council said it was closely monitoring the situation, paying particular attention to the potential for coastal inundation. MetService’s marine forecast was currently forecasting an easterly swell rising to 2m.
“We are closely monitoring weather forecasts, and river mouths, deploying additional generators and pumps, reviewing flood response procedures, and staying in regular contact with MetService and Civil Defence Emergency Management, and other councils,” the council said in a statement.
“In Wairoa, over the next two days, our contractor Prydes Contracting will be on site carrying out maintenance work on the Wairoa River bar.
“In addition, we are reopening the Tukituki River mouth as a precautionary measure. We will continue to update the community as more information becomes available.”
Napier City Council said its operations teams were actively preparing, including clearing drains, sumps and grates across the city, checking key infrastructure, and preparing generators and other response equipment.
“As always, getting ready is a shared effort, and we’re encouraging residents to play their part by clearing gutters and ensuring culverts and drains near their properties are free from leaves and debris,” a spokeswoman said.
With public events planned in Hastings this weekend, Hastings District Council said it is monitoring the weather conditions and may postpone the opening of the Osmanthus Lantern Festival from Sunday to Monday.
“The community will be informed if it changes,” a spokesperson said.
“Council is keeping a close eye on the weather forecasts … with staff preparing a contingency plan in case the cyclone lands here. Council’s three waters and roading contractors are on standby to deal with any issues and maintain services.”
Central Hawke’s Bay District Council duty manager Brent Chamberlain said the council was monitoring the situation and preparing to stand up a response if required.
Prime Minister Christopher Luxon said the weather was likely to have an impact.
“We’re encouraging people to stock up, get supplies and tie things down,” he said.
Luxon said emergency agencies were on standby and the public should use the time available to get prepared.
Residents were being urged to stay up to date with forecasts and prepare for unsettled weather heading into Sunday and early next week.