KEY POINTS:
Gales and heavy rain have been forecast by the MetService in a severe weather warning issued this morning.
People have been warned to expect swollen streams in Otago and Canterbury.
A northerly flow sweeping very humid subtropical air over the country was expected to strengthen from tonight.
The MetService said gales were likely in many parts of northern and central New Zealand.
Rain was forecast for northern Marlborough, Nelson, Buller and Westland, becoming heavy and persistent in later tonight, including the Richmond Range and Marlborough Sounds.
"Rainfalls in these areas are likely to be particularly intense near the ranges on Monday before easing on Monday night or early Tuesday morning," the MetService said.
"Totals could reach 200mm to 400mm near the ranges.
Heavy rain was also likely to spill over into the headwaters of Otago and Canterbury rivers tonight.
"People in these areas should watch for swollen streams and rivers," the MetService warned.
Surface flooding and slips were also possibly, especially tomorrow.
- NZPA
