Undulatus Asperatus: Rare Oregon coastal clouds explained

Josh Cozart
·1 min read

SEASIDE, Ore. (KOIN) — Undulatus Asperatus. What? Yes, that’s the name of this rare cloud formation seen over Seaside on Monday afternoon.

This cloud is relatively new to the atmospheric science scene and was the first cloud added to the International Cloud Atlas since 1951. It was proposed to the World Meteorological Organization as a new cloud in 2009 simply as ‘asperatus‘.

<em>Asperatus clouds seen over the Oregon Coast in Seaside Monday, December 18, 2023</em>
Asperatus clouds seen over the Oregon Coast in Seaside Monday, December 18, 2023

The strange wave-like clouds didn’t just appear out of now where. Then been happening since the weather’s been studied. It just wasn’t until recently that someone documented and named them that makes them so rare.

The wave-shaped clouds typically happen around 7,000 ft. and typically form from a weather system moving into the area. Topography can also help influence the formation of the turbulent clouds. The coastal elevation changes along the Oregon Coast along with the weak system seen moving onshore Monday are likely the cause of this rare cloud sighting in Seaside.

For the latest news, weather, sports, and streaming video, head to KOIN.com.