Metservice is warning that the weather system set to descend on the region on Thursday could be a "significant" rain event for Nelson Tasman.
Weather watches in place around the region have been upgraded to warnings as expected, with heavy rain set to arrive from early Thursday.
Metservice upgraded several heavy rain watches to orange warnings on Wednesday, with Nelson Tasman expected to see the heaviest rain in the country. The system is also expected to bring strong winds.
Tasman northwest of Motueka, including Golden Bay, is expected to see the worst of the rain with 350-450mm, possibly more, expected about the ranges between 3am Thursday and 10am Friday. There is a moderate chance the warning will be upgraded to a red warning - the most severe, by Wednesday evening dependant on how the weather system tracks onto the country.
Nelson's Bryant and Richmond Ranges, the Marlborough Sounds, Rai Valley and the inland Kaikōura Range are all under the same orange warning, with between 200 to 300mm expected to fall in the Richmond and Bryant Ranges and 100-150mm elsewhere between 11am Thursday and noon on Friday.
Nelson and Tasman remain under a heavy rain watch from 7am Thursday with periods of heavy rain expected.
