A large area of strong southwest winds, reaching gale to storm-force levels, is expected to form between the South Island and the Chatham Islands on Monday.
Heavy swell warnings have been issued for the lower North Island - between Cape Terawhiti to Mataikona - and MetService warns winds at the Chatham Islands may approach severe gale force during Monday evening and Tuesday morning, generating powerful swells around that area.
A strong wind watch has been issued for the Chatham Islands between 5pm Monday and 2pm Tuesday.
"Gale southwesterlies are expected. Although there is only a low chance they will reach severe gale over the Islands, there are accompanying large seas and heavy southwest swell which may result in waves of around 9 metres, or possibly more, on exposed coasts during Tuesday morning," MetService warned.
"Winds are likely to ease during Tuesday morning, but the large waves will continue into the afternoon."
MetService said people should take care, especially about exposed coasts, and keep up to date with the latest forecasts.
Heavy Swell Warning
Area: Wellington - Cape Terawhiti to Turakirae Head (mainly about the south coast)
Period: 3hrs from 3am - 6am Tue, 4 Jun
Combined wave: Southerly combined waves rising to 4 to 4.5 metres for a time Tuesday morning. Peak period 11 seconds.
Swell: Southerly swell rising to 4 metres for a time Tuesday morning. Period 15 seconds.
Heavy Swell Warning
Area: Wairarapa - Turakirae Head to Mataikona
Period: 14hrs from 1am - 3pm Tue, 4 Jun
Combined wave: Southerly combined waves rising to 4 metres overnight Monday, and to 4.5-5 metres Tuesday morning. Easing below warning criteria Tuesday afternoon. Peak period 14 seconds.
Swell: Southerly swell rising to 4-4.5 metres overnight Monday, then easing below warning criteria Tuesday afternoon. Period 14 seconds.
