Residents of Ōhope and New Plymouth saw their towns suffer intense winds last night - and a lengthy clean-up this morning - after tornadoes ripped through their respective towns.
Damaged fences and homes, shattered windows and a blown-off roof were among the casualties in Taranaki, while Ōhope Top 10 Holiday Park's functions centre was "completely blown apart" overnight.
While truly damaging tornadoes remain somewhat of a rarity in Aotearoa, MetService says a risk of them striking again tonight remains.
The North Island's encounter with them on Monday night proves they're worth knowing about - particularly as climate change makes extreme weather events more common.
Here's what you ought to know.
What are tornadoes and why do they occur?
Civil Defence defines tornadoes as rapidly rotating columns of air extending to the ground from thunderstorms.
In New Zealand, they are primarily caused by a type of storm known as pre-frontal squall lines, which NIWA explains are "bands of thunderstorms embedded in a strong, unstable pre-frontal northwesterly flow".
Tornadoes here generally travel across land for between two and five kilometres, with wind speeds ranging between 115km/h and 180km/h.
Why did last night's tornado occur?
Last night's tornado came about because the country is currently under quite a broad area of low pressure, which means there's a higher possibility of thunderstorms forming, MetService explained.
The increased instability in the atmosphere is causing the tornadoes.
The moderate threat of thunderstorms is not expected to clear until after tonight, according to MetService meteorologist Andrew James - so the risk of more tornadoes persists.
Does New Zealand even have a tornado problem?
New Zealand has about seven to 10 moderate to strong tornado events each year, according to NIWA.
MetService told Newshub the West Coast in the South Island and Taranaki in the North Island are where we're most likely to get tornadoes, owing to their exposure to prevailing westerly winds.
The damage tornadoes cause here is often minor, as they tend not to be very big or last that long; they're between 20 and 100 metres in width, and only remain active for a few minutes.
In contrast, areas overseas that are prone to tornadoes - think Oklahoma in the US, home to the infamous 'Tornado Alley' - can see them last for over an hour and span over 1km in width.
But while they aren't as big, they can still cause some serious damage - and occasionally prove deadly.
Three people died in a tornado in the Auckland suburb of Hobsonville in December 2012, while another was killed in nearby Albany in 2011.
How do I know when tornadoes are going to happen, and how do I prepare?
Tornadoes occur during thunderstorms, due to the increased instability in the atmosphere.
But other than keeping a careful eye on developments when a thunderstorm starts up, NIWA says there are particular warning signs to pick up on when a tornado is about to begin.
These include large hail, dark low-lying clouds, clouds of debris, or loud continuous rumbling.
Civil Defence advises that people develop a Household Emergency Plan and assemble a kit consisting of Emergency Survival Items.
It also says properties should be prepared for high winds - which means large objects should be secured and you should check your roofing.
What to do in the event of a tornado
If you're inside and see a tornado getting close, Civil Defence advises that you take shelter immediately. If it's further away, do your best to alert others.
The best shelter is a basement - but if the building you're in doesn't have one, it's best to go to an interior room with few windows, and on as low a floor as possible, before covering yourself with something sturdy like a table.
If there's little time to act, Civil Defence says you should get under a door frame or up against something that will support you.
If you're outside, trees should be avoided at all costs - and you should try and find a ditch or a gully to lie in. It is best to protect your head with an object if possible.
Newshub.
