MetService says a strong-to-gale northwest flow will hit southern and central New Zealand both today and tomorrow.
Waka Kotahi NZTA has warned of rockfalls and flooding on SH6 between Cromwell and Haast that has caused issues for drivers, and care is required driving on this route.
SH6 CROMWELL TO HAAST - ROCK FALLS - 10:30 AM TUE, 2 AUG Rock falls & flooding, in this area of SH6, are causing issues for road users. Please drive to the conditions & take extra care until conditions improve. ^SM pic.twitter.com/er5MRbxnh5
— Waka Kotahi NZTA Otago & Southland (@WakaKotahiOS) August 1, 2022
State Highway 8 between Tekapo and Pukaki was closed due to fallen trees. The trees came down between Braeman Rd and Hayman Rd. The road is now open and motorists asked to take care in the windy conditions.
According to MetService it has been a wild and windy morning across central and southern New Zealand. Wind gusts of 100km/h have been recorded at Fairlie, Roxburgh Airport, Dunedin Airport and Birchwood.
Aoraki/Mt Cook Aerodrome has recorded a gust of 109km/h while Puysegur Point and Mid Dome at the far southwest of the South Island have been hit with 156km/h winds.
The system is expected to bring periods of heavy rain to western areas and near the Southern Alps.
Canterbury is in the firing line with an orange heavy rain warning issued for the headwaters of the Canterbury lakes and rivers south of Arthur's Pass.
"Expect 120-160mm to accumulate near the main divide, and 80-110 within 25km east of the main divide. Peak rates of 20-30mm/h in possible thunderstorms near the divide. Note, freezing level about 1900m," MetService said.
"Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous."
An orange strong wind warning is also in place for the Canterbury High Country on Tuesday, with strong northwest gales forecast to become severe with gusts up to 120km/h in exposed places.
"Strong wind gusts could damage trees, powerlines and unsecured structures. Driving may be hazardous, especially for high-sided vehicles and motorcycles."
A strong wind watch is in place for Christchurch, Banks Peninsula and the Canterbury Plains, with northwest winds set to approach severe gale force in exposed places.
The forecaster also says rain could reach "warning amounts" from Fiordland to western Nelson, also extending to far western parts of Southland and Otago.
The Otago Daily Times reported up to 110mm of rain is expected to fall in the area until 10am Tuesday.
Surface flooding and slips are also possible and driving conditions may be hazardous.
Peak rates of up to 30mm/h may fall during possible thunderstorms.
Heavy rain may cause streams and rivers to rise rapidly, MetService said.
Strong wind watches are also in place for all of Otago, Southland, Fiordland and Stewart Island.
Later on Wednesday and Thursday, a ridge of high pressure moves eastwards across New Zealand, bringing calmer conditions and temperatures in the mid to high teens for many areas.