New warning levels designed for better accuracy


Always the toughest job for storm predictors is matching people’s level of concern to the level of threat. Weather forecasting is an inexact science, but it often offers us the chance to be prepared for the kinds of things that took our grandparents by cold surprise.

Weather systems that might produce tornadoes, damaging straight-line winds, hail and flash floods can be identified, but how severe the weather will become right where you are — that’s not something we can do with consistency.

Following outbreaks of severe weather, like the storms that spawned deadly tornadoes in Moore, Okla., last year, people listen to forecasts more closely and take warnings more seriously. But if a couple of warnings are issued without severe weather following, people go back to being complacent.

The National Weather Service’s Storm Prediction Center in Norman, Okla., is aware that the danger of issuing too many warnings can be as dangerous as not predicting enough.

That’s why the center is tweaking the kinds of warnings it issues around thunderstorms, starting sometime this spring.

Now, when significant severe weather — tornadoes, high winds, significant hail — is forecast, current labels describe the risk as slight, moderate or high, according to an Associated Press story. Because a few of those slight-risk days turned out to have pretty bad weather, officials at the Storm Prediction Center believe a fourth level, “enhanced,” in the spot between slight and moderate is warranted.

Without the new rating, conditions that seemed to indicate more than a slight risk, but less than a moderate one, were labeled “slight,” according to the AP report. But forecasters are not satisfied with that.

“Some ‘slight risk’ days are really quite active,” Russ Schneider, director of the Storm Prediction Center, told the AP. “You can get some strong tornadoes those days.”

Forecasters will also be able to use “marginal” to describe risks less than slight but more than nothing.

Guidelines at the other end of the scale, moderate and high, remain unchanged.

David Maxwell, director of the Arkansas Department of Emergency Management, explained how the levels translate into action in his department.

“We start paying attention on slight risk,” he told the AP. A moderate or high risk initiates conference calls with county emergency managers to make sure they’re ready.

All of this planning pays off if it means no loss of life.

Science is improving our ability to forecast conditions that could be life-threatening, but it will mean nothing if people whose lives are threatened are not listening. By adding more nuanced descriptors, the Storm Prediction Center is working to make sure you don’t tune out reports of severe weather. But in the end, you will be the one making the decision to prepare or to ignore the warning. We hope you will choose to listen and be grateful, not annoyed, if bad weather passes you by.

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This editorial was originally published in the Southwest Times Record.