Mt. Rainier: Despite the Downpour, It's "Ruh-near," Not "Rainy-er"

What is the collective noun for a bunch of stereotypes? Perhaps "a convention of stereotypes"? At any rate, a lot of them presented themselves as I enjoyed a ride across Puget Sound aboard a ferry this past weekend.

One stereotype was missing--the rain--which made it possible to enjoy the rest, such as harbor seals, sailboats, tugboats, gulls, and the city skyline glowing in the warm light of early evening, with the Space Needle standing apart from its less funky counterparts downtown. I'd perched right at the front of the ferry, in the "King of the World" spot favored by Leonardo Dicaprio, so this space-age wonder was all the way to the left of my view, with another space-age thrill capping the ultimate stereotype far to the right: UFOs over Mount Rainier.

The things hovering over Mount Rainier weren't really UFOs, of course. They were "cap" or "lenticular" clouds and looked rather like a stack of pancakes soaked in syrup.

But a little more than 60 years ago, a series of lenticular clouds may have kickstarted a UFO craze and inspired the first use of the term "flying saucer." In 1947, a pilot named Kenneth Arnold spied nine weird objects hovering over Mount Rainier and the Cascade range while flying from Chehalis, Washington, to Yakima. Back then, of course, he couldn't snap photos with a phone and tweet the news to the world. Instead, he contacted the press. In the media frenzy that followed, his description of the objects as saucer-shaped quickly morphed into "flying saucers."

Many theories exist regarding what Arnold saw or didn't see, and one of them suggests that the nine weird objects were just nine of these weird clouds.

The clouds are beautiful and strange, adding mystery to a mountain that disappears for weeks on end, thanks to the weather, then suddenly reappears, prompting people to declare, "Oh, the mountain's out today," as if it were perfectly natural for a 14,411*-foot-tall active volcano to vanish and then pop up again.

So the lenticular clouds capping the mountain over the weekend didn't augur little green men--just rain. It seems that when you see these formations, you're in for some soaking in the days ahead.

"How do these remarkable clouds form?" you ask? What a good question. Let's try to answer it, shall we?

Like the rest of the Cascade range of which it's part, Rainier blocks the flow of moist air traveling from west to east. The air is forced to flow up and over the peak. The air cools as it rises and its water vapor condenses, forming a smooth, rounded cloud. The front part of the cloud disappears as it descends because the air warms up as it flows down the other side of the mountain; meanwhile inflowing air continues to turn into cloud at the other end. So what looks like an unmoving cloud-cap on Rainier's head is actually a river of moisture-laden air briefly made visible for a portion of its journey.

According to Cliff Mass, whose beautiful book The Weather of the Pacific Northwest resides on my books-to-buy list, lens-shaped "mountain wave clouds" may also stay intact long enough to string out for miles on the mountain's lee side.

Not that we're seeing any more of them this week. The mountain was right. Rain!

*Give or take a few inches. Rainier was remeasured in summer 2010 using the latests GPS technology. Back in 1988, it was the first major mountain peak to be measured using GPS, and its height came in at 14,411 feet. However, it was thought that Rainier may have shrunk or grown in the interim (not a stretch for a mountain that can become invisible or give rise to UFOs). But luckily for Rainier, it won't need to buy a new wardrobe anytime soon. The measurements varied by mere inches, so the overall height remains the same.