EVERYBODY talks about the weather - nobody does anything about it. So goes the perennial complaint. But the way everybody talks about the weather is changing, with semantic refinements being invented to match the electronic refinements of TV weather maps. Just in time to dramatize the 120-degree heat in New Mexico and Texas, a new term has been coined, dripping with virtual sweat: ``apparent temperature.''
Encapsulating into data the folk wisdom that it's not the heat, it's the humidity, ``apparent temperature'' measures the oppressively sticky effect on human skin of a pure scorcher combined with an attack of the muggies. Thus when the thermometer in Philadelphia reached 99 degrees, the ``apparent temperature'' read as 110 - just what a perspiring world needs to know!
Among cases of information overload, the weather forecast is beginning to rank high. As news bites grow shorter and shorter, the time allotted to weather stretches longer and longer. The TV viewer waiting to learn whether to carry an umbrella or not is subjected to detailed and far-reaching meteorological asides, reporting low-pressure troughs in the Mississippi Valley and cool fronts stalled in Canada while simulated vapor swirls in the background like the witches' scene in ``Macbeth.'' By the time the forecaster - after an obligatory joke with the anchor team - reaches the bottom line, the weather-watcher's eyes have long since glazed over.
The effect of these new indexes is to make weather seem a not only complicated but dangerous business as well. If the ``apparent temperature'' is tolerable, the pollen count will be a menace. The very latest indicator - the Ultraviolet Index, measuring a day's potential for sunburn on a scale of 0 to 15 - will keep the adventurer who dares to go out at all swathed from head to foot like Lawrence of Arabia and greased in sun-block.
Life was simpler and less scary when state-of-the-art forecasting consisted of sticking your hand out the window, squinting at the nearest weather vane, and muttering, ``Red sky at night, sailor's delight.'' No mumbo jumbo about ``apparent temperature'' in the summer or wind-chill factor in the winter.
Was such primitive, 30-second forecasting accurate compared with today's endless readout from the computer? Of course not. But the element of surprise had its charm - and think of the time everybody saved.