Heavy rain and gale-force winds are expected in the Nelson Tasman region overnight and into Thursday.
MetService is forecasting 200 to 300 millimetres of rain in some areas, along with east to southeast gales in exposed areas with possible gusts 110km/h.
Care is being advised around rivers and tributaries and the Nelson and Tasman councils are asking residents to ensure that their drains are clear.
Tasman District Council spokesperson Chris Choat says the combination of strong winds and wet ground may cause damage to trees.
Council staff will be monitoring the situation, he says.
