At 6:30 on a February morning, the TV weather announcer suddenly turns into a wardrobe consultant. Ignoring actual temperatures, he concentrates on wind-chill, telling ''folks'' in Philadelphia they should dress for three-degree weather. Working his way up the East Coast, he advises New Yorkers to suit up against an even colder wind-chill factor and warns viewers in Boston to dress for readings that will feel like 8 below. Brrrrr, a listener thinks, heading for the closet to find something warm.
The weatherman - never leave home without him.
As it happens, although the day is chilly, it hardly merits the kind of sartorial overload he suggests. Yet his unsolicited advice - call it the wardrobe factor - adds to the drama Americans have come to expect from weather reports. It also helps ensure his place in a new elite of self-appointed authority figures influencing public behavior and popular belief.
Once upon a time, voices of authority primarily belonged to parents, teachers, and bosses. Before the arrival of wind-chill indexes and assertive TV forecasters, it was our mothers' voices echoing in our heads that reminded us on blustery days, ''Be sure to wear your boots, and don't forget your mittens.''
Now the advice we're supposed to obey comes increasingly from a host of TV personalities we've never even met, acting in loco parentis as they tell us how to dress, when not to venture out, what to eat or not eat, and how to care for our bodies. From weather announcers sternly telling listeners to ''bundle up'' and ''leave your car at home'' to TV doctors with their ''medical minutes'' and capsule descriptions of the ailment-of-the-day or the latest forbidden food, everything seems fraught with danger. Even summer, beautiful summer, is suddenly a season filled with pollen counts, ultraviolet indexes and a mysterious new equation some Florida weather announcers call ''humiture.''
Some of the advice these new protectors offer proves useful and necessary, of course. But not everyone regards it as an unmitigated blessing. When the subject is meteorology, hairdressers and other professionals whose income depends on scheduled appointments find that when forecasters issue ever-earlier warnings about potential bad weather, phones start ringing with cancellations. A decade or so ago, one retailer in the Midwest even threatened to sue a TV station because business dropped every time forecasters told viewers, ''If you don't have to go out tonight, stay home.'' The store argued that it was the station's duty to present the forecast, not tell people what to do.
If Americans a century or two ago were as cautious as everyone today is supposed to be, the country might not have been settled when it was. Had all those brave adventurers heading west in covered wagons been bombarded with warnings about wind-chill in the winter and humidity in the summer, would they ever have found the right time - and the courage - to leave home? On the other hand, a 19th-century version of the Weather Channel might have saved the lives of the Donner Party, half of whom perished in a late-October snowstorm in the Sierra Nevadas in 1846 on their way to California.
Could a barrage of constant warnings from these new voices of authority eventually turn America into a nation of scaredy-cats? Probably not. Yet perhaps it's little wonder that more people are choosing adventure vacations - from whitewater rafting in Colorado to trekking through Nepal and bungee jumping at Victoria Falls in South Africa. It's a chance to live daringly, out of earshot of all the constant health and weather cautions.
In a few weeks the winter of '96 will be only a memory for the record books. Weather announcers will have to find new seasonal warnings. March winds (''Hold onto your hats today, folks'') will give way to April showers (''Don't forget your umbrellas!'') and eventually to summer heat waves (''Remember your sunblock''). The human race wouldn't want to give up talking about the weather. But the forecaster who insists on turning into a behavior adviser might make at least some of his listeners want to try.