In Hawke's Bay and Gisborne more than 100mm of rain may fall in 24 hours, from Friday morning through to Saturday evening.
In Nelson, Buller and Westland southeasterly gales could become severe on Friday, lasting until Saturday morning.
In northeastern parts of Northland heavy rain is expected on Thursday afternoon when up to 30mm is expected.
MetService advises people to stay up to date with the latest forecasts in case these weather watches are upgraded.
Forecast
Auckland
• Today: cloud will increase, with rain developing in the afternoon. Northeasterlies will strengthen.
• Tomorrow: early showers will possibly become heavy with a developing south easterly.
Hamilton
• Today: early fog will lead onto cloud and then afternoon rain with northeasterlies will develop.
• Tomorrow: rain will ease and then clear.
Palmerston North
• Today: high cloud will thicken as strong easterlies develop.
• Tomorrow: rain will ease and then clear, with a strong gusty southeasterly.
Wellington
• Today: cloud will increase along with southeasterly winds.
• Tomorrow: rain will ease to showers and southerlies will rise to gale.
Christchurch
• Today: northeasterlies will develop with cloud cover and fine afternoon breaks.
• Tomorrow: occasional rain will clear with southerlies that will die out.
Queenstown
• Today: will become fine with light winds and a later southerly change.
• Tomorrow: becomes fine early, south easterly will die out.
Dunedin
• Today: a sunny day with northerlies can be expected, with cloud and a southerly at night.
• Tomorrow: a few early showers, then fine weather is expected. Southerlies dying out in the evening.