Cloud varieties go way beyond the cumulus, stratus, and cirrus we learn about in elementary school. Check out these wild natural phenomena.
STANDING IN A CORNFIELD IN INDIANA, I once saw a fat roll cloud (like #4 below) float directly over my head. It’s a 12-year-old memory that remains fresh. There was a moment of mild panic just as the cloud reached me — Is this what a tornado looks like right before it hits? I thought. This is some freaky unnatural shit and I do not know how I’m supposed to react.
I imagine a lot of these photographers having similar hesitations as they set up for the shots below. While it was relatively easy to put together this collection due to the huge number of crazy cloud pictures available online (did you know there’s a Cloud Appreciation Society?), many of the phenomena shown here are pretty rare…and potentially panic-inducing.
Lenticular cloud, Mt. Fuji, Japan
Altocumulus lenticularis is one of the more obviously 'bizarre' cloud types -- they don't occur too frequently, so when you see one, you take notice. They often form above or near mountains, as moist air flows rapidly over a rise in elevation. Mt. Fuji makes a pretty sweet base for this one.
Mammatus clouds, Ft. Worth, TX
Another rare and easily recognizable variety, mammatocumulus tend to spill out from the base of massive thunderheads in a characteristic blanket of pouch-like nodules. Generally a good cue to head indoors.
This one's so rare it doesn't even have official classification. "Undulatus asperatus" is its proposed designation, and if accepted as a new form by meteorologists, it'll be the first such addition since 1951. As of now, it's just another example of New Zealand having the coolest freakin' landscapes.
A variety of arcus cloud, tube-shaped rollers are completely detached from the cloud bodies around them and appear to roll as they move low across the sky. Here, Red Bull athlete Jonny Durand hang glides Queensland's "Morning Glory."
Some of the highest and rarest clouds on Earth, nacreous clouds form 10+ miles up during winter over polar locations like Antarctica. They are thought to exacerbate the effects of human-caused ozone depletion by producing chlorine, which destroys ozone.
From Matador managing editor Carlo Alcos, friend of the photog: "Taken July 11, 2012 in Nelson. Heavy rain and thunderstorms this summer have caused rivers and lakes to rise to levels not seen in several decades. Numerous evacuation alerts have been issued and a landslide in nearby Johnsons Landing wiped out homes and the only road access to the community. Four people have been missing since, two of them recovered from the debris. Another man died on June 23 in the Slocan Valley when he was swept away by flood waters from a bridge he was standing on."
Altocumulus formations usually comprise many individual cloudlets and take shape at heights of 6,500 to 23,000 feet. The whorls visible in this altocumulus layer, as seen from the International Space Station, are caused by two regions of ocean air moving at different speeds.
Photo: Cosmonaut Fyodor Yurchikhin and the Russian Space Agency Press Services
When caught in dusk light, any cloud becomes more dramatic -- particularly a rare formation like this mammatus, photographed above New York City in 2009.
Sometimes a little water vapor makes it 50 miles up into the mesospheric layer of the atmosphere and freezes to create noctilucent clouds. Again, the ISS provides a unique perspective from which to photograph these super rare formations, illuminated by an obscured sun.
Another iteration of Australia's famous Morning Glory, this time with multiple roll clouds. The area around Burketown is known for the phenomenon, most likely to appear between September and mid-November.
A similar phenomenon to a rainbow, the fog bow features much smaller droplets of moisture and because of this lacks all but faint color. Usually they appear white, as in this shot taken outside Sydney.
In January of 2009, this roll cloud was seen over the beach resort town of Punta del Este. Roll clouds most often appear in coastal areas -- the circulation of sea winds plays a part in their creation.
I'm not sure if conditions for crazy lenticular action are riper in New Zealand than elsewhere, but I'd definitely believe it based on this photo collection. The formation above seems like another candidate for the proposed "undulatus asperatus" classification.
Here's another example of the highest-forming cloud type (as much as 50 miles up in the atmosphere). In the foreground is Kuresoo bog, in southern Estonia, which provides a pretty amazing reflection scenario.
The intended subjects of this NASA satellite image are the very faint north-south-running lines of color, known as "glories," visible to the west of Guadalupe Island. I included it here because I like the more apparent von karman vortices, the swirls trailing off to the island's south.
These clouds are the visible manifestation of an otherwise invisible process; Wikipedia explains: "The Kelvin–Helmholtz instability (after Lord Kelvin and Hermann von Helmholtz) can occur when there is velocity shear in a single continuous fluid, or where there is a velocity difference across the interface between two fluids."
Referred to as a "cloud accessory," pileus formations are extremely short-lived. They form in similar fashion to lenticulars, only over clouds in place of mountains. As shown above, they're thin enough to pick up some color from the setting sun.
Also known as hole punch clouds, these formations occur as the moisture in a layer of cirrocumulus or altocumulus starts to freeze and fall to earth. Alternatively, they may signify an isolated pocket of evaporation.
As air travels over a raised land feature, it sometimes forms an atmospheric wave on the opposite side of the feature. Air then essentially surfs the wave, and when moisture conditions are right, these characteristic cloud bands are the result.
From the photographer: "I was out Weather Spotting for Buffalo County.... Just a beautiful shelf cloud and perfect conditions for this storm. Had to drive like a banshee to get back in front of the storm once it got too close. By far my best of 2009."
Wall clouds form beneath the underside of cumulonimbus clouds, typically within the zone where rain is not produced. Wall clouds that demonstrate rotation could indicate that a massive tornado is imminent.
This one certainly has the look of a violent supercell storm, but it's hard to tell from this distance -- what makes the difference is whether there's a persistent rotating updraft within the formation.
From the photographer: "I took this in 2002 in Lebanon, Missouri. I saw the clouds roll in and knew I had a few minute window to get a possible picture. I high tailed it from my place (about 3/4 mile) to get a nice view."
The photo above is from a NASA study on the wake vortices of aircraft. Here, the vortex phenomenon is made observable with the use of colored smoke. The formation occurs naturally in many diverse scenarios -- tornadoes, hurricanes, and cyclones being obvious cloud-related examples.