Rainbow Cloud In Lancaster, MA

reply to post by radpetey


hope not .... maybe its the military base near by lol ... na the only thing i know the military base near me is doing is testing a new tech that could pin point where a bullet comes from in the woods

I saw EXACTLY the sight you picture in your video when I took my dog and daughter out to the park the other day. I stopped and pointed it out to my daughter and explained it appeared to be a sun dog. I'm just trying to remember exactly which day we saw it. I think it was March 7, as I look over my instant messages to my husband I see a message to him saying I'm taking the kid and dog to the park. It is also possible we went out in the 12th, too. I see a text saying everyone was hyper to go out. But I didn't say I took them out and I honestly cant remember. You would think I would remember something like this but I've been very busy and had too many things to keep track of for the school events we are participating in this month.

I'm in Maryland. It is cool to see that others have seen this interesting phenomenon too. It has been a very long time since I've seen one of these.

As others have pointed out, this is not a "rainbow cloud" or "circumhorizon arc".


The sun has to be higher than 58° above the horizon for a circumhorizon arc to be visible, and it is obvious from the footage that the sun was relatively low in the sky at the time.

Latitude is the key. The sun must be higher than 58° to form the arc.

atoptics.co.uk

A circumhorizon arc would also be below the sun, where as what we are seeing in the footage is next to, and apparently more or less level with the sun. That suggests "parhelia" or sundogs.

Having observed and photographed sundogs on dozens of occasions, I would have to say that they look like sundogs to me.

One thing you can do if you see a patch of high-lit cloud to check if it is a sundog, is to stretch out your arm and whilst spreading out your thumb and fingers as far as they will go, cover the sun with your thumb/little finger, and use the finger/thumb at the other end to gauge the distance to your suspected sundog.

If your hand's span more or less reaches, then you are probably looking at a 22° sundog (the most common type). The same trick can also be used to identify the 22° halo that sometimes surrounds the sun, and often accompanies sundogs.

Originally posted by FireballStorm
As others have pointed out, this is not a "rainbow cloud" or "circumhorizon arc".

A circumhorizontal arc can be difficult to distinguish from an infralateral arc when the sun is high in the sky.The former is always parallel to the horizon,the latter curves upwards at its ends...

Near the middle of the page in this link are photos that clearly show what some types of circumhorizontal arcs look like > Circumhorizontal Arcs > en.wikipedia.org...

reply to post by blocula


Good point, and thanks for the link

I'm still learning all the arcs/halos, and have yet to see an infralateral of a CHA, so I'm not sure but I think that if the colours are vivid and intense it's a CHA. An infralateral won't usually have vivid colors as far as I know, but I could be wrong.

Since CHAs can also be less than vivid in colour, it would be harder to tell between them in that case I would assume.

reply to post by FireballStorm
I saw a bright and massive double rainbow here in mass. last summer right after a rain storm as the sun was coming out,it was the only time i ever saw one and it stretched across the sky from horizon to horizon and i even photographed it with a high quality fuji digital camera,but for some reason,the colors in the photos o took came out faded and can hardly be seen...

reply to post by blocula


Care to post the photo? I may be able to diagnose the problem.

I suspect the camera may have over exposed the rainbow by the sound of it. Were you letting the camera choose the settings?

Here's a shot of a circumhorizon arc that I posted on another thread in a previous incarnation here on ATS.



I usually end up choosing a different exposure to the one that my camera recommends, more often than not a little under-exposure. I always work in manual mode, and take a series of exposures, both under, and over what is recommended by my camera.

In my experience, the sky is often tricky to photograph, whist keeping particular elements saturated. I often find that a little post-processing to increase the saturation of the image slightly can help to return the vividness back to the scene.

All day long, clouds passed across the sun, and almost every one entered and exited with rainbow effects. I snapped a few with my 80-400mm lens on my Canon 7D. Here is my favorite:

reply to post by zayonara


Nice shot zayonara

Definitely Iridescent Clouds. They can often be seen when clouds are near or passing in front of the sun, but they're usually not as widespread and colourful as they are in your shot.

Polarizing sunglasses can help to make iridescence stand out a bit more when the colors are more subtle and hard to spot.

Has nothing on a double rainbow........

Thanks. Heading out to photoshop a triple rainbow....

How about a quadruple rainbow?