Parts of New Zealand are in for a wet and thundery end to the weekend as a cold snap sweeps across the country.
MetService has issued several heavy rain warnings and watches, as well as a severe thunderstorm watch.
The warnings come as a strong southerly wind change moves up New Zealand, bringing rain and cooler temperatures.
Severe thunderstorm watch
Thunderstorms are expected to develop in the Canterbury Plains on Sunday afternoon and evening, bringing heavy rain with intensities of 10 to 25mm/h, hail 10 to 20mm in diameter, and strong wind gusts of 90 to 110km/h, MetService says.
"There is also a moderate risk of severe thunderstorms developing south of about Rakaia, bringing the possibility of damaging winds gusting greater than 110km/h and also the risk of a small localised tornado," they say.
"Wind gusts of this strength can cause some structural damage, including trees and power lines, and may make driving hazardous. If any tornadoes occur, they will only affect very localised areas."
Several heavy rain warnings
There are also heavy rain warnings for parts of the West Coast and the lower North Island.
Until 8pm, Westland between Otira and Haast can expect a further 120 to 180mm of rain on top of what's already fallen, bringing rainfall totals for the event to 400 to 500mm or possibly more, MetService says.
"Coastal areas can expect a further 60 to 90mm of rain to accumulate. Expect peak hourly rates of 20 to 30mm/h, mainly about the ranges," they say.
"Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous."
As mentioned, Canterbury is also in for heavy rain. The area of the headwaters of the Canterbury lakes and rivers about and south of Arthurs Pass can expect a further 100 to 150mm of rain about the divide, and 50 to 70mm within 15km east of the divide.
There is a further heavy rain warning for the Tararua Range that is set to last through to the end of Monday. Those in the area can expect 120 to 180mm of rain to accumulate, with peak rates of 15 to 25mm/h, especially during Monday morning.
The Mount Taranaki area is also in for a wet couple of days, with 120 to 180mm of rain expected to accumulate, with peak rates of 15 to 25mm/h, especially over Monday morning.
Heavy rain watches
The top of the South Island and lower North Island is in for some heavy rain over the next two days, where the amount that falls may get close to warning criteria.
The heavy rain watches are:
- Buller, from 9am to midnight on Sunday
- Tasman west of Motueka, from Sunday 4pm to Monday 3am
- Richmond and Bryant ranges including the Rai Valley and northern parts of the Marlborough Sounds, from Sunday 6pm to Monday 11am
- Wellington and Wairarapa south of about Greytown, from 3am to 9am on Monday.
