Jellyfish Clouds

It’s funny how things that pop into your head as questions get answered the next day. I was looking at these strange clouds yesterday. They looked like jellyfish because they had hanging tendrils under them. I had never seen clouds do that. Then the next morning I was watching the news and the meteorologist was talking about the same thing. She even said they look like jelly fish.

 Speaking of meteorologist, what do you call the female ones if they aren’t meteorologists? Some of them don’t have the degree. We call the men weathermen but what do they call the women? Back in the dark ages they called them weathergirls. Apparently back in the day, women who had the same job as men weren’t allowed to grow up. I’ve never thought of that.

Anyway, I digress. So I looked up the jellyfish clouds and this is what I learned today on Weather.com (you know I didn’t write this stuff).

They are called altocumulus castellanus. When warm, moist air rises, the invisible water vapor eventually cools and condenses into tiny water droplets on particles called condensation nuclei. As the process continues, water droplets further accumulate upwards, creating visible heaps in the sky known to us as white, fluffy clouds.

However, in the case of jellyfish clouds, the warm, moist air can only rise so high in the atmosphere before it gets stuck. The moist air encounters an area of much drier air, which causes the moisture to evaporate at a faster rate than it can condense. Essentially, the cloud vaporizes at this height of the atmosphere, thereby stunting the cloud's growth and producing the "dome" portion of the jellyfish cloud.

At the same time, water droplets within the cloud are becoming too heavy to remain suspended in the air. As gravity pulls the water droplets toward the ground, they encounter yet another layer of dry air and evaporate before they can strike the surface of the earth. This phenomenon, known as virga, produces the tendril-like streaks in the sky below the altocumulus dome.

Jellyfish clouds develop during fair weather days, when there is enough moisture in the air to produce clouds but not enough for them to grow large or to produce rain.

So now you know.