Motorists are urged to take care on the roads this week, as the top of upper South Island braces for more rough weather

MetService has issued a heavy rain warning for Buller and western areas of the Tasman district.

Heavy rain watches are also in force for Nelson and the Marlborough Sounds.

Waka Kotahi is warning bad weather could create issues on the state highway network, and motorists need to be prepared in case road closures occur.