Quake-ravaged regions are bracing for a fresh onslaught of heavy rain, thunderstorms and bitterly cold gales set to batter central New Zealand in the next 48 hours.

The MetService has issued a severe weather watch today that stretches from Buller through to Taupo.

It warns there will be another burst of heavy rain for many areas already deluged this week by torrential downpours. The quake-devastated Kaikoura Coast and Wellington are set to be battered by cold southerly gales.

Snow is also expected across the Canterbury high country tonight with road snowfall warnings for major alpine passes.


Meteorologist Tom Adams said the rain wouldn't be as intense as yesterday, but with the ground already sodden there was a chance of flooding.

There wouldn't be prolonged periods of rain, but thunderstorms could bring heavy falls particularly on State Highway One near Porirua and on the Kapiti Coast.

A burst of heavy rain is set to fall on Buller to northwest Nelson and western regions of the North Island from Wellington to Taupo from this afternoon.

Tomorrow the weather takes a wintry turn as cold southerlies blast the east coast bringing rain and gales to Kaikoura, Marlborough and Wellington.

The MetService has issued a road snowfall warning for Lewis, Arthurs and Porters passes. They say from tonight until midday tomorrow up to 10 cm of snow could settle near the summit.

The New Zealand Transport Agency warned the coming bout of wet weather could cause further disruption across the Wellington region.

"We are expecting rain through to Friday. While it won't be as heavy or intense as Tuesday, there is still ongoing risks of further slips which may require emergency work to clear. Some parts of the network have suffered significant damage and will require further assessment to identify permanent repairs, and motorists may continue to experience delays to the journeys," said regional performance manager Mark Owen.

On Friday, the cold southerly flow is expected to ease, but another front is expected to move north over the South Island, bringing further rain to western areas.