Strange Clouds a Work of Mother Nature with Help from Mankind

Aug 10, 2013

Did you see them?

A line of unusual triangular-shaped clouds resembling prayer flags draped over us earlier this week.

“We call these mare's tails or fall streaks in the business,” says Cliff Mass, KPLU weather expert and professor of atmospheric sciences at the University of Washington.

The clouds were the work of Mother Nature, but with a little help from mankind.

“We had the upward motion in the upper atmosphere that was getting close to saturation. So we were getting a little bit of  cirrus developing,” said Mass. “Then, it appears to me looking at a few of the cam animations that are available, that a few contrails were produced by jets. That actually initiated the lines of these cirrus clouds, and then these lines started precipitating out.”

What resulted was the string of pointy clouds that made for quite a show.

“So it was kind of complex, but it wasn’t due to aliens or chemtrails or anything like that,” Mass said. “It’s a natural phenomenon that probably was initiated by some jets flying overhead.”

Mass says these mare's tails occur from time to time, but rarely to the dramatic extent we saw this week.

“To have it in such beautiful lines and to have such dramatic, full streaks of cirrus was, you know, kind of unusual, but it does happen,” he said.


The weekly KPLU feature "Weather with Cliff Mass" airs every Friday at 9 a.m. immediately following BirdNote, and twice on Friday afternoons during All Things Considered. The feature is hosted by KPLU Environment Reporter Bellamy Pailthorp. Cliff Mass is a University of Washington Professor of Atmospheric Sciences, a renowned Seattle weather prognosticator, and a popular weather blogger. You can also subscribe to a podcast of “Weather with Cliff Mass” shows.