Fox News’ Janice Dean went berserk yesterday in a forecast on the impact of Hurricane Sandy. “Catastrophic damage,” “historic” and “worst-case scenario” three times — those are the things that Dean said, though the true level of hysteria can be appreciated only by watching the video above.

Dean’s hype outstripped the language and breathlessness of other organizations, ones that give tons of thought to just how they articulate the storm and the threat it may pose to the population. Thanks to some extended interviews with weather fiends, here’s a little cheat sheet on how to avoid overdoing the weather forecast.

*Be careful with “catastrophic.” This is the word that defines scaremongering for weatherpeople. Don’t just throw it around. “Literally, we don’t use that term” absent extraordinary circumstances, says Bryan Norcross, senior director of weather content and senior hurricane specialist at the Weather Channel. That said, the Weather Channel does have a weather classification system that spans the following terms: AWARE, ALERT, ACTION, EXTREME, CATASTROPHIC. In order for the Weather Channel to trot out the CATASTROPHIC term, the storm must be strong enough to wipe an area clean.

*Explain! Forecasters have been fond of calling Hurricane Sandy “historic” and “unprecedented,” terms that can stir fear among the public. They may well refer to the meteorological happenstance of a tropical storm making the acquaintance of a nor’easter off the East Coast. That’s rare enough to qualify as history. You just don’t often see a storm that “comes out of the Bahamas, then heads out to the ocean and takes a hard left and heads toward New Jersey,” says Bob Ryan, senior meteorologist at WJLA-TV in Rosslyn, Va. The tropical-nor’easter combo affects the winds and moisture in the storm, says Ryan, but that doesn’t mean that it’ll be the most destructive storm in history.

*Timing! Ringing the bell too loudly too early, says CNN meteorologist Chad Myers, creates mayhem and not much else. “My mom is the biggest worrywart,” says Myers. If a tornado is projected for Tuesday, “don’t tell her on Sunday. Don’t make people panic before they need to.” And don’t wait forever, either. With a hurricane on the way, for instance, people can’t wait until the winds come before protecting their property. “You can’t handle plywood when the wind is blowing 20 mph,” says Myers.

*Tone! People who watch a weather forecast on TV aren’t necessarily listening carefully to all the words. Norcross says that one of his colleagues has paid a great deal of attention to the imperative of “controlling hyperbole.” The important thing, he says, is to keep forecasters “paying attention to the impact of their message and the impression that what they say leaves. You can be truthful but be inaccurate” in tone, says Norcross.

*Credibility! Exaggeration has huge consequences, as WJLA’s Ryan notes. “People get unnecessarily frightened and they’re preparing for something that is really terrible and then it doesn’t happen, and then the next time you say it’s a catastrophic storm and they say, ‘We don’t believe you,’” says Ryan. (Full disclosure: Ryan is a former colleague of mine.)