Atmospheric conditions which seamlessly fell together are the reason behind why a number of wave clouds have been spotted across Tauranga skies.

MetService meteorologist Tom Adams says the clouds were spotted from as far as south of Tauranga and all the way up to Matakana Island.

'It's a phenomenon which happens quite frequently in New Zealand.

'You see it a lot in the South Island where westerly winds sweep over the Southern Alps, but it's less common in the North Island because the mountains aren't as big.”

Tom says they come in two types.

'There's trapped and untrapped mountain waves, which is to do with the stability and direction of the wind as you go up through the atmosphere.

'The kind that have been spotted in Tauranga are of the trapped variety, which are lower down.

'This actually makes them appear a lot more obvious to the public because they are closer and from a position on the ground you can quite often see more of the lines, whereas when they are higher they tend to be more spread out.

'What has been spotted in Tauranga is a distinctive cloud formation and it makes for some great pictures.

'It's caused by south-westerly winds blowing over the Kaimai Ranges. The atmosphere was in such a way that it caused these trapped mountain waves and a lot of people spotted it.

'These formations are relatively common but it is rare to get such a good example of it, all of the things fell together to make these clouds quite distinctive and that is a lot less common.”

And here's the view from above, imagery courtesy of JMA. Despite some higher cloud moving over the top, the wave clouds are seen clearly, parallel to the Kaimai ranges. ^TA pic.twitter.com/YTbDuUKK9L

— MetService (@MetService) April 23, 2018