In the upper North Island, southern Canterbury, North Otago and Dunedin are advised to have emergency supplies in preparation for a severe weather bomb as Civil Defence and emergency services across the country gear up.

MetService is predicting  24 hours of severe gales and heavy rain with streams and rivers expected to rise quickly.

Up to 70 mm of rain is forecast to fall in Northland and northern Auckland.

Up to 160mm is predicted for Coromandel Peninsula, Bay of Plenty, Gisborne and Tongariro National Park.

And as many as 250 mm of rain could hit the hills around Dunedin and swamp  Canterbury, Marlborough, Westland, Buller and Nelson.

County99TV News and Weather climate scientist Dr. Jim Salinger says farmers need to prepare for flash flooding by moving stock to higher ground as a precautionary measure.

Meanwhile, Federated Farmers dairy chairman Lachlan McKenzie says drought-hit farmers in low lying areas need to take extra care, as soil with little grass cover will flood quickly once drenched with fast and furious rainfall.