This was the view that surprised me the most: Bright orange (a little more magenta in real life than it looks here in the photo) on the underside of the clouds, but plain gray on the sides.

Here are a couple of views of the rainbow and Downtown Los Angeles in the distance, a little bit earlier.

Looking northwest across LAX toward the Santa Monica Mountains. The sun is out of frame to the left. Oh, who am I kidding? It was behind a building, so I aimed at what I could see.

More photos: LA post-storm rainbow & sunset

It was 90 degrees and sunny when I left the office a little after 6:00 pm, though the eastern half of the sky was dark with clouds. It started raining before I pulled out of the driveway. Just a little. I was halfway home before I decided enough of the raindrops were staying on the windshield that it would be worth turning on the wipers.

It was still spattering a little when I got home, but nowhere near enough to soak the ground. The drops were evaporating quickly. A far cry from the heavy rain and thunderstorms a few miles farther inland.

The rain’s stopped here, and the half-and-half cloud cover and sunset are giving the sky a dingy yellow color.

I saw this amazing circumhorizon arc around 1:30 this afternoon. I had just crossed the street while walking to lunch when I looked up, saw it…and walked back to the office to get my camera!

Lesson learned: always bring the camera!*

It started out as just a couple of small segments, but as the clouds drifted into position it quickly grew, and at its strongest it was just long enough to fill the field of view on my camera. There were also a couple of fragments of a 22° circular halo visible at the time.

The whole thing had vanished by 1:50, as the clouds drifted out of alignment, though I did see a more complete circular halo later on.

It looks like a sort of straightened-out rainbow, but it’s actually caused by ice crystals. If the right type of crystals cover the entire sky, this will actually stretch in a circle all the way around the sky, parallel to the horizon.

They’re a lot less common than the 22-degree halos. I’ve seen and photographed a ton of those over just a few years, but this is maybe the second time I’ve seen something like this. Fourth if you count the two feathery fragments I’ve seen.

At times like this, I really wish I had a DSLR, but the point-and-shoot will do in a pinch.

*On the other hand, when I went back, I pointed it out to a couple of people at the office who are into photography, since it was visible through the windows on one side of the building. One of my co-workers has a digital SLR and carries it with him, so he went outside and got some great shots. If I hadn’t taken a late lunch and chosen to walk anyway and been in the habit of looking for halos and forgotten to bring my camera, chances are no one in the office would have seen it.

Update (May 17): I just discovered that there are people who think these clouds are connected to earthquakes. No, they aren’t. They’re caused by ice crystals refracting sunlight, just like most halos, and have been seen in many places that didn’t have earthquakes.

I glanced out the window while eating lunch at Johnny Rockets and saw this brilliant rainbow. I hastily told the server that I would be right back, and was just going to look at it, and left some of my stuff at the table while I came out and snapped a picture. A passing security guard remarked that he had the same idea, but didn’t have his camera. When I went back in, two of the employees were staring out the window at it.

It basically is a rainbow, except formed by reflections in tiny glass beads (used for sandblasting) instead of raindrops. The physicist who posted his (much better) photo to APOD had a better camera handy. And a linear polarizer. (Don’t you always carry one of those?)

Sadly, I only had my phone.

It’s not as sharp as the one I caught 2 years ago, but there was more color. It was clearly reddish toward the inside and bluish toward the outside. Like last time, I didn’t have the good camera, just my cell phone, but at least this time it was a better phone!

This reminds me, our trip to San Francisco a few weeks ago was through patchy clouds, sun, and rain—perfect for rainbows. We spotted several, including one which was not only extremely bright, but actually showed supernumaries inside the band.

We saw this on Thursday, February 21, somewhere between Paso Robles and San Jose along US Highway 101. Katie remarked that it looked almost double-layered, I looked over, and said, “Grab the camera! It has fringes!”

I’d never seen, or never noticed supernumaries before. I’d never even heard of them until I was reading through Atmospheric Optics a few years ago. If you look on this color-enhanced picture (actually from another photo of the same rainbow), you can see several extra bands inside the violet arc, alternating green and pink.

The really weird thing? Classical optics doesn’t explain them. Refraction and reflection can only explain the red-to-violet band and the secondary bands that sometimes appear outside the main arc. These are actually wave interference patterns that occur if the water droplets are small enough.

On a related note, last Sunday (March 2) I saw what I’m fairly certain was a lenticular cloud, except it didn’t look remotely like a lens. It was just a long, narrow flat cloud floating above the Santa Ana Mountains. I noticed it around 3:00 in the afternoon, and a couple of very thin, also flat clouds above it, and thought it looked like the beginnings of the stack formation. What clinched it was the fact that the cloud was still there, 5 hours later (visible at night by reflected city light), despite the high Santa Ana winds. You know, after spotting two sets last summer, it looks like they form in Orange County a lot more often than I thought.

At sunset, there were clouds above us, rain in the east, and clear skies to the west, showing a bright orange sun. We looked to the east, and saw a huge rainbow. It was extremely high—it looked like it ought to be an entire circle, even though I knew it couldn’t be more than a semicircle. That doesn’t come through in the one photo that came out, since it’s a matter of perception: neither of us had ever seen a rainbow centered at the horizon before. It was also faint (I had to increase the contrast on this photo), and very red.

Google Images pulls up some nice pictures when you search for rainbow sunset. I particularly like this one at Flickr, which also shows spoke-like rays. Atmospheric Optics’ rainbow section is also worth a look, especially for some of the odd kinds of rainbows that aren’t often seen.