A tropical deluge is on the way for the West Coast with several hundred mm forecast, but the North Island may also get clipped by the same system later this long weekend and into next week.

The South Island is initially most exposed, mainly the West Coast, Nelson and Marlborough but Canterbury may also be affected by heavy rain and spillover rain in the waterways.

This weekend and next week rain then slides into the North Island with possibly heavy falls and flood potential too.

This is potentially one of the wettest nationwide setups NZ has seen in several months.

We cover the forecast through Waitangi Weekend and to the middle of next week.