Obviously, the past couple of weeks have offered up a stark reminder of what winter can be like here in the South Central Missouri Ozarks.
We who call the region home have experienced almost every possible form of precipitation, including rain, snow, sleet and freezing rain, and we’ve also seen our thermometers display some awfully frigid temperatures. While many of us have continued going about daily life, it’s safe to say that all the weather-related activity has made that a bit more challenging than it might otherwise be.
But while we hear those terms describing the various types of precipitation tossed about without hesitation on TV and radio weather reports, I’m pretty sure they fall into that category of familiar-yet-unfamiliar aspects the English language, as do so many other terms and phrases we pretty much take for granted.
In other words, I’m not sure people know exactly what they all really refer to.
Now, I’m no weather expert, but I did take a meteorology course in college, so I have a basic grasp of the scientific definition of each term. Plus, there’s that analytical mass inside my head that has led me to make sure I comprehend the matter.
With that in mind, here’s a little briefing on the subject.
We all know that water falling from the sky is called rain. And it’s really no secret that rain forms when moisture condenses into water droplets that become too heavy to remain aloft and are drawn to the Earth’s surface by gravity.
Rain isn’t often dangerous, but it certainly can be when enough of it falls in a short enough time to cause flooding.
OK, so this isn’t very tough, either. It’s frozen water that falls from the sky in the form of a “flake.”
Of course, we were all told as kids that no two flakes are alike. But maybe we don’t all know that those flakes are made up of a bunch of individual ice crystals that grow while they’re suspended in clouds, and then fall prey to the Earth’s gravitational pull and descend to the ground (where they can sometimes pile up and either wreak havoc or offer significant recreational value).
Like snow, sleet is also a form of frozen water aloft. But it differs from snow in that there are no crystals; it’s basically pellets of ice formed by frozen raindrops or snowflakes thawing and then refreezing.
Sleet can be ugly as heck when it piles up; it’s notorious for being more slippery than snow.
Simply put, it’s drops of water that fall from a relatively warm air mass into a freezing air mass. So it begins as rain and then freezes when it reaches the surface.
On their way to the ground, the raindrops are cooled big-time as they pass through a colder layer of air, and then freeze when they land on things like tree branches, vehicles, power lines and a variety of other surfaces. That’s why freezing rain (and the “ice storms” it’s associated with) can be one of the most problematic types of precipitation.
The thickness of the “glaze” that forms determines the amount of danger or damage, simply because of the weight of the ice.
Thankfully, we haven’t seen any of this lately.
Like sleet, hail is made up of solid chunks of ice. But “hailstones” differ in that they are usually layered and irregular and are made up of a bunch of chunks clumped together.
Hailstones typically form in thunderstorm clouds, mainly those with considerable height, intense updrafts and high water content, and where a major portion of the cloud is below freezing.
As we who live in these parts all know (based on what happened last March), hail has the potential to be an incredibly damaging form of precipitation.
•The continent that receives the least precipitation on Earth is Antarctica.
•The world record for the most snowfall in a season is 95.01 feet, recorded in 1998 – 1999 at Mount Baker Ski Area in Whatcom County, Wash.
•Only a week or so ago, rain was falling at the house where my wife and I live and the temperature was 19 degrees Fahrenheit.
•The heaviest hailstone on record weighed 2.25 pounds. It fell in Bangladesh on April 14, 1986. The largest hailstone on record measured 7.9 inches in diameter and 18.622 inches in circumference. It fell in Vivian, S.D. on July 23, 2010.