The Ice Storm, to judge by the reviews, is not a film with a cheerful narrative. Despite, or perhaps because of, the best efforts of Kevin Kline and Sigourney Weaver, it paints a depressing picture of the 1970s, with a climax, apparently, that takes place in the middle of that eponymous and very American meteorological phenomenon. The antihero, if I understand the blurb correctly, makes a rather shocking discovery in the ice, and then the aftermath of the storm brings about a cathartic reunion of the film's dysfunctional family.
But what exactly is an ice storm? A blizzard, as we all know very well, is an unpleasant combination of snow and strong winds, but an ice storm is a phenomenon that is almost unknown to us in Ireland and very rare in western Europe. But they are common enough in wintertime in the north-eastern quadrant of the United States.
An ice storm is an event which, if the distribution of temperature in the atmosphere were slightly different, might be a harmless spell of rain instead, or at worst a period of snow. Given critical conditions, however, the precipitation comes in the vicious guise of "freezing rain". The term "storm" - as in the case of "snowstorm" - is misleading; the freezing rain may, or may not, be accompanied by gales, but it is the ice that does the damage.
Temperature, as we know, normally decreases steadily with height. In such circumstances, snowflakes falling from a cloud survive as snow if it is cold enough adjacent to the ground, or melt and fall as rain if the temperature is much above the zero mark. Sometimes, however, there occurs a thermal distribution in the vertical we call a "temperature inversion" - a shallow wedge of warmer air some distance from the ground; an ice storm becomes a probability if temperatures are above zero in this warm layer, and below freezing near the ground.
So what happens to our snowflake in these circumstances? Drifting down through the warm air near the inversion, it melts into a raindrop - but as the raindrop nears the ground, the temperature becomes low enough for it to want to freeze again; it does so, very rapidly, on making contact with any solid object.
Freezing rain coats everything with layers and layers of hard solid ice, called "glaze". Roads become impassable, every tree becomes a wilderness of icicles, and every exposed wire becomes a translucent elongated cylinder. In severe cases, overhead power cables become so thickly coated that they topple their supporting poles, or break completely with the unaccustomed weight.