APOD: Roll Cloud Over Wisconsin (2011 Aug 31)

[APOD Robot]

Roll Cloud Over Wisconsin

Explanation: What kind of cloud is this? A type of arcus cloud called a roll cloud. These rare long clouds may form near advancing cold fronts. In particular, a downdraft from an advancing storm front can cause moist warm air to rise, cool below its dew point, and so form a cloud. When this happens uniformly along an extended front, a roll cloud may form. Roll clouds may actually have air circulating along the long horizontal axis of the cloud. A roll cloud is not thought to be able to morph into a tornado. Unlike a similar shelf cloud, a roll cloud is completely detached from their parent cumulonimbus cloud. Pictured above, a roll cloud extends far into the distance as a storm approached in 2007 in Racine, Wisconsin, USA.

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[MSP1]

It seems that the number of terrestrial scenes with some astronomical scenes in the background are increasing on APOD and today we have a scene with no astronomical details at all. What do others think about this? Personally, I prefer pure astronomical pictures. There are dozens of sites on which I can find terrestrial views and, if all else fails, I can look out the window.

One more thing, while I'm talking about my personal preferences, I wrote a simple program which changes my desktop picture automatically to be the APOD so videos are a bit of a nuisance

[owlice]

What do others think about this?

This other thinks Earth is fair game and that this is a fabulous image. I'm glad I get to see it via APOD! Would probably not have otherwise.

APOD always informs.

[Guest]

Explanation: What kind of cloud is this? A type of arcus cloud called a roll cloud. These rare long clouds may form near advancing cold fronts. In particular, a downdraft from an advancing storm front can cause moist warm air to rise, cool below its dew point, and so form a cloud. When this happens uniformly along an extended front, a roll cloud may form. Roll clouds may actually have air circulating along the long horizontal axis of the cloud. A roll cloud is not thought to be able to morph into a tornado. Unlike a similar shelf cloud, a roll cloud is completely detached from their parent cumulonimbus cloud. Pictured above, a roll cloud extends far into the distance as a storm approached in 2007 in Racine, Wisconsin, USA.

The caption says these "Roll clouds" are rare. Hmmm, Wisconsin, about 5 miles or so from Lake Michigan. I can't say that I see these clouds all the time but often enough. I expect the lake has a lot to do with it. Many summer days here, I'm just north of Milwaukee about 3 miles east of the lake, you can see fair weather cumulus clouds advance east across the sky and stop where the afternoon lake breeze pushes them back.

[Steve Case]

It seems that the number of terrestrial scenes with some astronomical scenes in the background are increasing on APOD and today we have a scene with no astronomical details at all. What do others think about this? Personally, I prefer pure astronomical pictures. There are dozens of sites on which I can find terrestrial views and, if all else fails, I can look out the window.

One more thing, while I'm talking about my personal preferences, I wrote a simple program which changes my desktop picture automatically to be the APOD so videos are a bit of a nuisance

You're right, but it's the one's with terrestrial stuff in them that I usually stop to admire.

Deep sky galaxies? As fantastic as they are, they're boring.

[ianchristie]

I tend to agree that terrestrial pictures are all very well but not here. As roll clouds go this one is fairly ordinary by comparison with those seen almost daily in the Northern Territory. See the image here:
http://en.wikipedia.org/wiki/File:Morni ... mPlane.jpg

[owlice]

I tend to agree that terrestrial pictures are all very well but not here. As roll clouds go this one is fairly ordinary by comparison with those seen almost daily in the Northern Territory. See the image here:
http://en.wikipedia.org/wiki/File:Morni ... mPlane.jpg

Or just click on the "roll clouds" link in the text of today's APOD to be taken to this APOD.

[orin stepanek]

These kin of remind me

Click to view full size image

Of these

Click to view full size image

[moonstruck]

A nice apod. Anyone who doesn't like any picture that comes up can just go to the archives and I'm sure you can find enough astronomy pictures to last you all day. Anyone shouldn't come to a free site and bellyache about it.

[geckzilla]

Ok guys... I know people get upset every time there's not a beautiful galaxy to gaze at but providing you a pretty picture is not all of what APOD is about. I will quote this again as I have quoted it in the past. APOD editors have been at this for over 15 years now.

I posted that video to APOD. About once a month or so, APOD posts an image that is not strictly related to the classical definition of astronomy or space science. Reasons for this are several, including broadening APOD's reader base. APODs like these, in my opinion, interest people in space, science, and astronomy who might not normally have or follow such interests. In my view, the web appears to stratify people by interests, and many times people in one interest group will not wander into other interest areas. Eclectic APODs like this are therefore an attempt to reach across disciplines.

Additionally, in my view, APOD is also about planet Earth, exploration, and making connections between science and things not classically related to science. In this case, this APOD focussed on humans specifically, who have never been highlighted on APOD before. This also gives APOD a "human" link usable inside of future APODs.

- RJN

This is in reference to the Happy People Dancing APOD. You can read the ensuing discussion about it here. It's actually an interesting read to see how various people responded to it. Anyway, while this roll cloud isn't as far off as happy people dancing, the general idea is still the same. It's a free service and the editors have dedicated countless hours of their lives to help educate the masses a little bit more every day with a single picture, video, or illustration and that's the whole point of APOD. They shouldn't have to apologize for doing the best that they can at it.

[nstahl]

I was on a small boat in a big lake in Canada, no other boats around. I looked up and saw one of those, going from horizon to horizon. I'll never forget that sight.

[saturn2]

Roll Cloud is a peculiar cloud, is an arcus cloud.
The black sky preyect a big shadow over the city.
This image look like a surrealist picture.

[DavidLeodis]

I've noticed that the image is credited to 'Pierre cb' but in the information about the image brought up through the "Pictured above" link it states "This work has been released into the public domain by its author, Eazydp". Unless 'Eazydp' is the same person as 'Pierre cb' I think the image should therefore be credited to Eazydp. The image is in Wikimedia Commons, where, as I understand it, image information can be edited by anybody, but not the image. The image is though a good one.

[owlice]

David, look at the file history; the image is credited to Pierre cb.

[DavidLeodis]

David, look at the file history; the image is credited to Pierre cb.

Thanks for that clarification owlice, which is appreciated. From the "This work has been released into the public domain by its author, Eazydp" in the information with the image in Wikimedia Commons I assumed that meant Eazydp took the photo. It is all very confusing (well it is to me. ).

[eazydp]

Hi there: My wife is the actually photograph, this Pierre Cb person is actually not the photographer, but rather my wife, and I was the uploaded to Wikimedia commons. I have emailed the APOD staff asking them to update the credit.

I can clarify the exact location of the photo was literally on the Lake Michigan waterfront in Downtown Racine. A huge wind and rain storm broke out, tornado sirens began, and then this amazing cloud rolled across the horizon out to the Lake. It was terrifying! Luckily my wife had the sense to snap the picture with her digital camera.

Anyways, thanks for the concern about the credit, you were correct!

Dave