It's A Bird, It's A Plane, It's....A Jellyfish???

For everyone in Seattle last Tuesday, August 6th, they were enjoying another beautiful, sunny, warm day. However, there were a few unique clouds that interrupted that peaceful day, and had locals wondering what on Earth might be in the sky. "Mini-cyclone" clouds, "Jellyfish" clouds, or "Ice cream cone" clouds as they are often referred to, because of their shape, made a rare appearance in Washington. Their technical term is actually "Fall Streaks", which are a form of virga.

Courtesy: Dale Jordan in Washington

Courtesy: Brian Lutz in Washington

Virga, is rain from a cloud, but that rain never actually makes it to the ground because it evaporates too quickly. Fall streaks are similar, but instead of being in the form of rain, they are ice crystals. As those ice crystals "fall" from the cloud they change directly from a solid to a gas state, or sublimination.

Notice in the picture below that there is one line of "jellyfish" clouds in the western section of the state near Seattle, and another in the eastern section of the state.

As to the reason why they formed on what would have otherwise been a completely clear day: something called a line of deformation. When you have two low pressures, flanking an area on each side, they tug and pull on the area in between. For that area in between that "tugging and pulling" created lower pressures overhead, and that creates the higher level clouds (usually filled with ice crystals).

This isn't the first place to see these strange clouds. Last year similar clouds popped up in Iowa. Thankfully, I think we can all rest soundly knowing that these are not part of an alien invasion or conspiracy theory :)


Courtesy: Danny Murphy in Iowa

 Sources: KOMO News, Atmospheric Optics, KWWL-TV