Freak Forecasts: Bizarre Weather Phenomena
-40 degrees. It’s a special temperature.
When it's 40 below outside, not only can you throw boiling water in air and observe what's called “deposition” (a gas turning directly into a solid)—but you can also ignore what kind of thermometer is on the wall. -40 is the only temperature reading that is the same in Celsius and in Fahrenheit.
Our biosphere is chock-full of meteorological oddities: freakish cold snaps, dust devils, rains of frogs or fish. Here is a sampling of the oddest of the odd:
Red sprites and blue jets. First proved to exist in 1989, these lightning-like flashes occur above thunderstorms. Way, way above them. In a storm, common lightning bolts are 5 to 10 miles high—they’re the ones we know, the bolts that split trees, blow circuit breakers, and stun golfers. But above a storm’s cauldron of rain and hot electrical activity, other things are going on.
Occasionally, a storm cell will release a giant, reddish charge into the upper atmosphere—called a “sprite,” these discharges of energy can top out at 30 to 55 miles high, practically high-fiving the ionosphere. Sprites are triggered by a large, normal lightning flash lower down. Less common—and unrelated to surface lightning—are “blue jets,” another upward-moving bolt of energy occurring at lower altitudes (25 to 30 miles up) and giving off, as the name suggests, a bluish light.
St. Elmo’s fire. It's mentioned over and over throughout history, often in nautical accounts—in the writings of Julius Caesar and the letters of Charles Darwin, in Robert Burton’s Anatomy of Melancholy and Herman Melville’s Moby-Dick: a violet-bluish glow on the tips of masts, chimneys, lightning rods, even the horns of oxen. These crackling, plasma-globe-like electrical emanations—named for St. Erasmus (or Elmo) of Formiae, the patron saint of sailors—have been scaring the pants off sailors for millennia. Melville writes: “All the yard-arms were tipped with a pallid fire...each of the three tall masts was silently burning in that sulphurous air, like three gigantic wax tapers before an altar” (Moby-Dick, Ch. 119, “The Candles”).
St. Elmo’s fire has rarely, if ever, been caught on film. And it is not the same as ball lightning, a much more debatable phenomenon. The latter is supposedly a free-floating ball of electrical charge, said to zip around erratically, often coming in windows or doors before sizzling out.
Lenticular clouds. These have something in common with ball lightning (if that can be said to exist). Both are periodically mistaken for UFOs. Lenticular clouds have a very distinct structure: they look like opaque saucers or lenses (lenticula = Latin diminutive for “lens”). They commonly form when moist air is forced into a hump over a mountain—this air condenses into cloud and, as it dips down again, evaporates back into water vapor. A lenticular cloud may look inert, but it’s more like the standing foam on a flowing wave.
Another type of capping cloud, called a “pileus,” forms over other rising air masses rather than mountaintops. Pilei can be seen over cumulus clouds, nuclear explosions, even volcanic eruptions—as on June 12, 2009, when the International Space Station took this startling video-like series of photos of Sarychev Peak, a violently exploding Russian volcano.
Sun dogs. In 1461, the War of the Roses was in full swing in England. Prior to a decisive battle at Mortimer’s Cross, Edward, Earl of March (soon to be King Edward IV), saw a strange sight in the sky: three suns. Today, we know he and his troops were witness to “sun dogs.”
Properly called a parhelion, a sun dog occurs when sunlight bends through a high, icy haze in the atmosphere. On either side of a faint halo around the sun appear two bright—sometimes very bright—spots, the result of refraction. Edward and his Yorkist troops were able to take the triple sun positively. He declared it a good thing, a Trinitarian sign—and they won the battle.
Giant snowflakes/hail. The largest snowflake on record fell in Fort Keogh, Montana, in January 1887. According to the Guinness Book of World Records, it was 15 inches in diameter—about the size of a frying pan. The biggest flakes are created when thousands of symmetrical, 6-sided snow crystals freeze into one large disk.
Large hailstones, on the other hand, form when updrafts force hail back into the clouds over and over again, where they collect layer after layer of ice. What finally comes out of the sky is layered like, and sometimes the size of, an onion. The biggest hailstone ever discovered fell in 2003, on a house in Aurora, Nebraska. It was 7 inches wide—menacing, but unlikely to kill you.
Simoom. If you've read The English Patient, you’re familiar with it: a dry, blistering, desert wind that screams in and wreaks absolute havoc. The simoom (from the Arabic “samma,” meaning hot or poisonous) is a hot wind that occurs in the Sahara and the Middle East. While not the meteorological assassin it is sometimes made out to be, its choking dust and dry, kiln-like atmosphere have been known to cause people and animals to die of thirst.
Snowspouts and fire whirls. Think dust devils are odd? Fire devils, or flaming vortices, often occur during big conflagrations—wildfires, oil fires, and the like. Most are small and localized, but they can occasionally grow to an enormous size: in 1923, after an earthquake in Yokohama, Japan, fires—including a titanic fire whirl—burned an estimated 39,000 to death in Tokyo. Less common and less deadly are snowspouts, a.k.a. winter waterspouts, which form when cold air masses over significantly warmer water. Few have ever been photographed.
Artificial Weather. Humans have been modifying the weather for over 60 years. Prior to the 2008 Summer Olympics in Beijing, for example, China launched rockets over Beijing to induce rainfall. It's called cloud seeding—using a plane or rocket to disperse particles (usually silver iodide) in the atmosphere. The particles form ice crystals and, with luck, rain-bearing clouds. Silver iodide was first used for this purpose in 1946, by an atmospheric scientist working for GE in Schenectady, NY.
He was Bernard Vonnegut, older brother of novelist Kurt Vonnegut, Jr.