Taranaki residents may have been left wondering whether the region was being invaded by UFOs today, but they are in fact lenticular clouds.
A 1 NEWS viewer from Stratford sent in two stunning images of the unusual formations this afternoon.
1 NEWS meteorologist Dan Corbett said the formations are more common around geological formations like mountains, making Mount Taranaki a prime candidate.
"Think of the mountain like a ski slope - it lifts the air, and then you get all the air coming together, like layers of atmosphere, and as it starts to come down on the downward slope, the air will start to spread out," Corbett said.
"It's almost like an accordion, how the air spreads out.
"It's Mother Nature saying, here - some fancy clouds, don't worry, it's not the mothership."
Strong west-south-westerley winds were hitting the mountain, being compressed, and expanding as they come down the other side.
"Strong winds and stable air" can also be ideal conditions for wave clouds to form, Corbett said, which have a repetitive, ripple-like look to them.
For a full forecast for your region, see our weather section here.