‘Tis the season to … slip and slide, shovel snow, deal with black ice and freezing fog. Yes, at this time of year, Mother Nature dishes up a mixed bag of precipitation, each presenting its own challenge for walking, driving and generally just getting around.
When you listen to the local weather forecast it gets even more confusing. Do you ever wonder what the difference is between freezing rain, sleet and freezing drizzle? In my book it all translates into leaving early for work, driving even more defensively and generally making for a challenging day all the way around.
All this winter weather affects us in more ways than we sometimes realize. Not only does it make commuting difficult, it basically rearranges everyone’s schedules. Think about it; schools either run late or let the students out early, which means schedules with daycare and babysitters have to be re-arranged; patients cancel appointments, thus altering schedules for doctors and nurses; delivery people have a hard time maneuvering and end up working longer hours; and the list goes on and on.
Weather is the focal point of conversations more than any other topic because weather affects everyone everyday. Remember when the forecast used to be simple. When snow was predicted, it was just snow. Now we have lake-effect snow. Freezing rain meant exactly what it said, not freezing drizzle or freezing fog or sleet. In the summers, we would have tornadoes, so what’s up with straight-line winds?
Through all this muck I decided to get a little weather-savvy and sort out all these terms that meteorologists like to throw at us. Here are some interesting facts I discovered:
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Let’s start with snow. Quite simply, snow is precipitation in the form of ice crystals, usually falling white flakes. When the term lake-effect snow is mentioned, it refers to cold winds moving across long expanses of warmer lake water like the Great Lakes. When this occurs, snow accumulation is heavier the nearer you are to the body of water. Here in Michigan when we hear the term lake-effect, it translates to mean “we’re going to be dumped on by snow, better head to the grocer’s because by noon the shelves will be pretty bare and by evening we have a 50-50 chance of either having 2 feet of snow or 2 inches.”
The adage that no two snowflakes are alike is probably true for fully developed flakes. Jon Nelson is a research scientist who studies snowflakes. Imagine that! Snow that reaches the ground in the early stages of development is basically all the same, consisting of six-sided prisms. However, once they start growing the crystals, each one picks up its own unique shape. If photographs of a million different snowflakes were compared at a rate of two every second, it would take 100,000 years for the comparisons and the odds are there would not be two exactly alike.
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All precipitation falls through the atmosphere, which is technically the air between the clouds and the earth. Differences in temperature in different parts of the atmosphere are responsible for determining if the moisture falls as snow, sleet, freezing rain or drizzle.
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Sleet is a snowflake that begins its journey frozen, passes through a thin layer of warm air and then goes through a pocket of cold air before reaching earth’s surface. The snowflake re-freezes and becomes an ice pellet that we call sleet, which bounces when it hits the ground.
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Freezing rain follows the same pattern as sleet. It starts as snow, becomes rain, but before hitting the ground it goes through a shallow pocket of cold air that cools it some but not enough to make sleet.
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Hail is a form of solid precipitation that is distinct from sleet. It consists of balls or irregular lumps of ice and usually falls during warmer weather as opposed to sleet, which occurs when temperatures are colder.
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Fog is essentially a cloud that visits the earth and lingers near the earth’s surface. Freezing fog is fog that is super cooled and, when it comes in contact with objects, will turn to ice. It is often accompanied by freezing drizzle, which is a film of ice that coats nearly everything. Ice fog consists of tiny ice crystals and occurs in cold Arctic air.
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Hoar frost is a term I only heard a few years ago. It is arrangements of ice crystals on surfaces. This usually occurs when there are very cold temperatures overnight and thick frost coats everything in sight the following morning.
OK, all this weather terminology is clear as mud now, which in itself is a whole other story. What it really all boils down to is, here in Michigan and other northern states, winter brings a mixed bag of precipitation that can change from moment to moment.
While it creates havoc on the roads and disrupts schedules and sometimes is just a plain nuisance, it can also give us some unprecedented beauty in the world around us. Since we can’t change the weather, we may as well embrace whatever is thrown at us and see the beauty in it. I’m sure I will be the first to remember this the next time I have to shovel my way out!
