Three nearly identical, UFO-like cloud formations recently appeared over Myrtle Beach, South Carolina, sparking online discussions linking the features to everything from the Second Coming to recent mass bird deaths to secret military experiments.

At least one scientist believes the so-called hole-punch clouds have a military explanation, though it may not be quite what conspiracy theorists expect.

On January 7, IT technician Wesley Tyler was running out to his car for a computer part when he noticed the saucer-like formations. (See other cloud pictures.)

"At first we thought they were tornado clouds, but the air was so still—like mausoleum still," Tyler said. "You just knew it was unusual. I've lived on the beach for years and never seen anything like that."

Back home, he uploaded pictures of the clouds to Facebook, tagging a meteorologist friend, who later identified the phenomena as hole-punch clouds, or punch-hole clouds.

Hole-punch clouds are miniature snowstorms that can occur in thin, subfreezing cloud layers.

The lack of fine particles, such as dust, in the clouds means water droplets have little to condense around, so they don't turn to ice until the cloud hits about minus 38 degrees Fahrenheit (minus 36 degrees Celsius).

"Basically, the water molecules become sluggish enough at this temperature to form their own cluster of ice that produces an ice crystal spontaneously," according to ice microphysicist Andrew Heymsfield.

When airplanes ascend into this type of cloud, the rearward force created by propellers or by air forced over wings causes air to expand.

This expansion can cool a vaguely circular section of the cloud to the point where many of the water droplets freeze and ice crystals form, according to a June hole-punch cloud study co-authored by Heymsfield in the Bulletin of the American Meteorological Society.

Over the next 45 minutes or so, ice crystals grow and spread outward, often resulting in a tightly contained, roughly half-hour snowstorm—leaving behind a hole "punched" in the cloud. (Related: pictures of a possible new type of cloud.)

Triple Hole-Punch Clouds Linked to HAARP, Heaven?

Tyler, the photographer, was skeptical of the airplane explanation, due to the sheer number and close proximity of the cloud formations.

"I've scoured the Internet and have yet to find more than one hole-punch cloud in a single frame," he said.

Myrtle Beach International, he added, is "not that busy an airport." And, he said, "I've read that these clouds form at 20,000 feet [6,100 meters], and these clouds looked like they were right above us.

"I doubt they were created by airplanes," Tyler concluded—and he's not alone.

After his pictures were posted on spaceweather.com, the Myrtle Beach (map) resident began hearing from people all over the world.

Some suspected a more colorful cause—perhaps the military-funded High Frequency Active Auroral Research Program, or HAARP, which conspiracy theorists have linked to earthquakes, chronic fatigue syndrome, global warming, and other phenomena.

Though remote, the observatory-and-antenna facility in Gakona, Alaska, is anything but secret. Even so, its use of radio waves to "excite" areas of Earth's ionosphere has helped convince some that HAARP can control weather—and perhaps even create triple hole-punch clouds.

"There is no doubt," one HAARP theorist wrote of the Myrtle Beach apparition on the Big Wobble message board, "it's an electromagnetic corridor produced by our technology." Another wrote on Starseeds.net, "This could be related to HAARP or some weather manipulation as it also ties in with the bird deaths."

And on Rapture in the Air, a site devoted to signs of the Second Coming of Christ, "mike" wrote, "Hope the photos was taken after 3 invisible space [arks] came down from heaven which the Lord has sent to earth. ... "

While Tyler doesn't necessarily buy these theories, he thought the airplane explanation was flawed. "There must be another explanation—natural or otherwise."

Military Responsible for Odd Clouds?

To Heymsfield, the physicist, the explanation is both natural and otherwise.

"To me, it's a slam dunk" that these are hole-punch clouds that were created the usual way—by planes—said Heymsfield, of the National Center for Atmospheric Research in Boulder, Colorado.

There's "nothing at all" surprising about the picture, he added.

For one thing, it's the right type of cloud—thin, with no other layers above it—as evidenced by the clear skies just beyond, he said.

And the cloud layer's temperature fits the hole-punch model: 14 degrees Fahrenheit (minus 10 degrees Celsius), according to National Weather Service records.

As for the cloud being low in the sky—9,000 feet (2,700 meters), according to the weather service—"it doesn't matter," as long as the cloud layer is cold enough, he said.

But why three together?

"The hole sizes and the structure of the snow falling out of the holes suggest that all three holes were made at nearly the same time," he said. "My suspicion is that military aircraft were flying in formation or one behind the other."

And in fact, it's "very common" for training maneuvers to take place over Myrtle Beach, according to Robert Sexton, community relations manager for nearby Shaw Air Force Base.

More to the point, Sexton confirmed that fighter jets from Shaw and from the South Carolina Air National Guard's 169th Fighter Wing were training off the South Carolina coast on January 7 between 9 a.m. and 2 p.m.

"After us, the Marines were in the airspace from 3 to 4 p.m. with F-18s" out of the Marine Corps air station in Beaufort, South Carolina, he emailed.

After having heard the new evidence, Tyler, the photographer, said he's convinced by the aircraft explanation, though he initially seemed slightly disappointed by its straightforwardness.