Most of the rain that starts at 7am Monday will be the biggest on the West Coast of the South Island. Image / weatherwatch.co.nz
Severe thunderstorm warnings have been issued tonight for the Canterbury Plains and North Otago, accompanied by heavy rain and hail that are likely to hit the area.
Other parts of the country will be hit by strong winds.
MetService has warned people in the Canterbury Plains and North Otago to be prepared for flash floods around low-lying areas such as rivers, streams or narrow valleys, which can cause slipping. Rainfall is expected to be more than 25mm in some areas.
A front moved eastward across the South Island overnight.
This means that heavy rain can occur with thunderstorms in the Westland region south of Otira, and in Dunedin and North Otago.
Driving conditions will also be dangerous, with surface flooding and poor visibility during heavy rain.
Heavy hail can cause significant damage to crops, orchards, vines, greenhouses and vehicles.
Northwest winds can reach heavy storms from inland Canterbury to Marlborough, Wellington and Wairarapa.
Meanwhile, a storm likely to bring destructive winds and heavy waves centered on New Zealand’s West Coast, prompting warnings for those camping, on foot or on the water.
Weatherwatch.co.nz estimates strong winds “damaging” more than 150 km / h, waves of up to 13 meters, and one meter of snow in the Southern Alps.
There may also be over 200 mm of rain for parts of the West Coast.
Police say they have not issued a specific warning for the storm, but they always urge motorists to drive according to the conditions.
“In wet and windy weather that means slowing down and increasing the distance to follow,” said a spokesman.
Philip Duncan at weatherwatch.co.nz said the storm would be significant.
“The stormy Southern Ocean weather pattern is temporarily putting the La Nina pattern to one side with two significant lows – one today and the other around Tuesday, Wednesday.
“Sunday’s low, which still hasn’t suppressed some thunderstorms, rain and winds for parts of New Zealand, will actually be tracing out of the country today. So we don’t expect anything too serious today, although it remains up-to-date with possible MetService severe warning no matter where you are. “
But the ensuing storm worries Duncan, especially for those venturing outdoors.
“The Tuesday / Wednesday event appears to be the most intense with the epicenter of this hurricane potentially crossing Southland and Otago.”
As a hurricane hits the country with its strong northwest strong winds, it will then be followed by a cool southern turn with heavy rains that will hit the West Coast.
Auckland is expected to cool down but will not experience as violent a storm as the South Island one.
MetService meteorologist Peter Little said southwestern changes that begin on Wednesday through Thursday will bring temperatures down to 10C on the South Island.
Dunedin will drop from 25C today to 15C.
Few say that temperature changes won’t be as dramatic as on the North Island, but people will definitely feel the impact from the southwest.
Auckland will drop from 27C today to 21C on Wednesday, and 20C on Thursday.
Until then, the hot weather will continue. Whangārei and Gisborne can expect temperatures of 30C, Auckland and Tauranga 27C and Hamilton 26C.
In today’s South Island, Kaikoura is a hot spot of 28C. Christchurch and Ashburton are set at 27C.
The front exerts its energies on the South Island, and central New Zealand – Wellington, Wairarapa – is bearing the brunt of strong winds. Bad weather warning has been issued.
-RNZ additional reporting