June 2021

These jellyfish clouds drifted in the air currents over Portland, Oregon, US, where they were spotted by Robin Cole (Member 44,966). The tendril-like streaks hanging from them are known as virga. They are in fact showers falling from clumps of the mid-level cloud called Altocumulus. There is no sting in these celestial tendrils. Instead, they’re filled with tiny, tumbling crystals of ice.

The cloud trails are known as virga rather than precipitation because they never reach the ground. Since Altocumulus clumps are quite high up – the ones here might be up at around 4 miles (6 km) – there’s plenty of atmosphere for the ice to fall through before reaching the ground. Often the air below the Altocumulus is warm and dry enough for the ice crystals to evaporate away as they descend. This change of state from ice to invisible gas, water vapour, is known as ‘sublimation’.

How easy is easy to forget that our atmosphere is an ocean of gasses – one that is similar to, and intimately linked with, its watery cousins like the Pacific and the Atlantic below. Easy to forget also that we are creatures of the deep, our daily dramas playing out right down on the ocean bed. When a shoal of virga cloud jellyfish drifts into vision like this, it comes to remind us we live within the sky not beneath it.

Altocumulus with virga spotted over Portland, Oregon, US by Robin Cole (Member 44,966).

5 thoughts on “June 2021”

  1. I saw them today in the Pyrenees Oriental I will try and upload a link

  2. Sherry Palmer avatar Sherry Palmer says:

    I would like to share with other members a link I just received from a friend to a video of a “flashing” rainbow on Yosemite falls.

    View Yosemite Falls Rainbow Video:


  3. Robert Huxham avatar Robert Huxham says:

    As Laurie says a really great photo. I’ve only seen a sky full of altocumulus virga only once in the UK (over Shropshire about 3 years ago) but, unfortunately, didn’t have the time to stop and savour this truly, impressive spectacle. Having just retired from work (yes!) I’m really looking forward to building up my personal gallery of cloud phenomena … how can anyone not love them?

  4. Kellogg Patton avatar fruitloops says:

    Thanks for the jelly fish explanation. I see them occasionally overhead – in the distance or hanging out over the mesas to the east – in the quad city area of Prescott, AZ – incorporating Chino Valley to the north, Prescott Valley to the east and I don’t know what the 4th city is in our “quad-city” area.
    These are my pre-cursor to Hope, my personal Rain Angel that maybe our drought might be in for a reprieve. My hope is peaked as I watch them develop into something more useful like precipitation actually hitting my windshield. Or disappear as a promise to return with a vengeance of a heavy down-pour triggering my outdoor spirit that maybe our dirt roads will soon be mud-bogging heaven.
    Or proving the adage – You Cannot Fix Stupid – to the drivers who don’t believe the ‘road closed due to flooding’ signs. Turn around…don’t drown!!

  5. Laurie Brown avatar Laurie says:

    A great shot, lucky yuo to be able to get something like that.

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