Wild weather's dangerous punch

00:29, Jan 09 2013

Heavy rain, severe gales and thunderstorms today will force people in the South Island and lower North Island to batten down the hatches.

MetService says intense rain in the South Island could cause slips, and rivers and streams to rise rapidly, while wind gusts of up to 140kmh in Wellington and inland Canterbury have the potential to uproot trees and bring down power lines.

A front that has intensified over the Tasman Sea as it heads to New Zealand has prompted MetService to issue a severe-weather warning for heavy rain in the west and south of the South Island, and northwest gales in eastern areas from Wairarapa to Otago.

People planning tramping or other outdoor activities in these areas should reconsider their plans as expected rain and wind gusts could be strong enough to make even driving hazardous, MetService said.

The heaviest rain today would be in Westland, where 300 to 400 millimetres was expected to fall in a 27-hour period.

Heavy rain was also expected in Fiordland and the headwaters of Otago and Canterbury lakes and rivers.

Wellington and inland areas of Canterbury could expect winds of up to 140kmh.

Northwesterly winds were expected to reach severe-gale strength in Otago, Canterbury, Marlborough and Wairarapa, while northerly winds could reach severe-gale strength in parts of Westland and northern Fiordland.

There was a moderate risk of thunderstorms in Fiordland this afternoon and in northern Westland and Buller tonight.

There was a high risk of thunderstorms in southern and central parts of Westland and the Southern Alps from this afternoon into the evening.

Any thunderstorms were likely to boost local rainfall rates up to 25mm an hour or more, MetService said.