An active front over the Tasman Sea will move slowly eastwards across New Zealand on Friday and Saturday, July 16 and 17, 2021. The front will bring heavy rain to the country's western areas, and northerly gales to much of central and northern New Zealand.
In light of this, New Zealand's MetService has issued Red Warning for Heavy Rain in northern Westland and Buller from 21:00 LT on Thursday, July 15 until early Saturday, July 17.
This is only the third Red Warning issued by MetService since the color-coded warning system was introduced in 2019. The most recent was for the heavy rain that caused significant flooding in Canterbury at the end of May this year for which a regional state of emergency was declared.
Red Warnings are reserved for the most impactful weather events and are only issued after close consultation with the relevant regional authorities including Council and Civil Defence Emergency Management teams.
Sideways rain forecast— MetService (@MetService) July 15, 2021
Along with the heavy rain we are also forecasting strong winds from the northwest in the next couple days.
Umbrellas wont stand a chance in Wellington where the Strong Wind Warning contains gusts of 140kmph in exposed places. ^Lewis pic.twitter.com/0Vq7eSnb6M
When it rains, it pours.— NIWA Weather (@NiwaWeather) July 15, 2021
Not only is torrential rain on Mother Nature’s menu, but howling winds are too
On Saturday, they’ll sweep across the North Island.
Potential impacts: downed trees & powerlines, damage to some structures, and difficult driving conditions. pic.twitter.com/F0Z5kaKBv7
Severe Weather Outlook— MetService (@MetService) July 15, 2021
Severe Weather Warnings and Watches have already been issued for some places that will be impacted by the significant heavy rain and gales this week. Additional regions may be added in the coming days.
Stay up to date at https://t.co/qHyE5zhh6X
‼️Nearly half a metre of rain is forecast high in the Southern Alps over the next 48 hours— NIWA Weather (@NiwaWeather) July 14, 2021
Areas of flooding and slips are likely
Rapidly rising rivers in the West Coast, inland Canterbury, and Tasman District
Don't drive through flood waters! pic.twitter.com/iLkcK7HaPj
"The West Coast is known to receive large amounts of rainfall but in this case, the amount and persistence of heavy rain forecast are at the tipping point to where we could see significant impacts for communities and transport links on the West Coast," said MetService meteorologist Lewis Ferris.
The current warning has rainfall accumulations between 300 and 400 mm (11.8 - 15.7 inches) from Thursday night to Saturday morning, with peak rainfall rates of 20 - 30 mm/hr (0.78 - 1.18 inches/hr) expected from Friday afternoon (LT).
This rain is expected to cause dangerous river conditions and may produce significant flooding. Slips and floodwaters are likely to disrupt travel, making some roads impassable and possibly isolating communities, the agency warns.
"We are asking people to act now to keep themselves and their whānau safe and to heed the advice of authorities," said Ferris.
"Anyone with travel plans in Westland and Buller on Friday and Saturday are urged to keep up to date with road information from Waka Kotahi NZTA. This is especially relevant due to the school holidays bringing more families to the West Coast. Please share this information with anyone you know traveling in the region."
There is also a Severe Weather Watch for Strong Wind in place for this region along with Orange Warnings and Watches for many areas across the country.
Featured image credit: MetService