Would the media and storm spotters PLEASE stop rating tornadoes before the official National Weather Service survey teams do!

A couple Fridays ago a radio announcer in Saint Louis assigned a tornado an EF-3 rating while the storm was still in progress, chewing through the city. More recently I read a news writeup in which the April 27 Tuscaloosa–Birmingham, Alabama, tornado was described as an EF-5, as though that rating were a done deal. At the time, the matter had yet to be determined by damage assessment professionals.

Both the Tuscaloosa and Saint Louis tornadoes were in fact officially rated EF-4. In one case the news medium underestimated the damage rating; in the other, it overestimated; and in both cases the media overstepped their bounds.

“EF-5 in Progress!”

It appears that a good number of reporters and storm spotters are prone to the same error that many storm chasers make: linking their impression of a tornado’s strength based on appearance–whether visually or on the radar–to an Enhanced Fujita scale (EF-scale) rating. Doing so demonstrates ignorance of what the EF-scale actually is: a tool that assesses and rates tornado damage, and from it extrapolates potential wind speeds. By its very nature, the EF-scale cannot be used to describe a tornado in progress; it was developed for use in post-mortem assessments of tornado events.

Expanding on the original F-scale criteria developed by pioneer tornado scientist Dr. Theodore Fujita, the EF-scale considers 28 Damage Indicators (DIs)–small barns or farm outbuildings, one- or two-family residences, strip malls, hardwood trees, and more–in rating tornadoes. Each DI is scrutinized according to its makeup, its circumstances, and the Degree of Damage (DOD) it received. For instance, did a hardwood tree sustain broken branches? How big were the branches? Was the tree uprooted? Snapped? Debarked, with only a stub of trunk left standing?

In its 95-page recommendation for an Enhanced Fujita scale that it submitted to the National Weather Service in June, 2004, the Wind Science and Engineering Department at Texas Tech University said:

Ideally the recommended approach for assigning an EF-Scale rating to a tornado event
involves the following steps:
• Conduct an aerial survey of damage path to identify applicable damage indicators and
define the extent of the damage path
• Identify several DIs that tend to indicate the highest wind speed within the damage
path
• Locate those DIs within the damage path
• Conduct a ground survey and carefully examine the DIs of interest
• Follow the steps outlined for assigning EF-Scale rating to individual DIs and
document the results
• Consider the ratings of several DIs, if available, and arrive at an integrated EF-Scale
rating for the tornado event
• Record the basis for assigning an EF-Scale rating to the tornado event
• Record other pertinent data relating to the tornado event.

Obviously this kind of information isn’t snap-judgment material. Making such assessments requires training and resources of a kind that most media personalities–and, for that matter, most storm chasers–don’t have.

The bottom line is this: It’s just flat-out wrong to rate a tornado in progress based on its appearance using the EF-scale. Also, while there’s nothing wrong with personally speculating about the nature of the damage you’ve observed in a tornado’s aftermath, remember that your opinion is unofficial.

Bear these things in mind the next time you hear someone say, “That’s got to be an EF-4!”–or the next time you’re tempted to say it yourself. Particularly if you’re a journalist. When you broadcast or publish as definitive what is in reality nothing more than your own or some spotter’s or chaser’s subjective opinion, you are misinforming the public. Your hunch might eventually be proved right, but it could also easily be proved wrong. Why create such confusion? It costs you nothing but sensationalism to refrain from presenting uninformed impressions as if they were fact. Leave EF-scale ratings out of the picture until the NWS has completed its investigation of an event and assigned official ratings.

So What CAN You Say?

You can describe a tornado that you are observing as weak, strong, or violent.

You can describe its size and/or appearance using subjective terms that are commonly understood by storm chasers and meteorologists. Small and large are good, as are wedge, cone, rope, stove pipe, and multiple vortex.

It’s correct to say, “That’s a small but strong tornado,” or, “There’s a large, violent, multi-vortex tornado in progress.” It’s incorrect to say, “Oh my gosh! EF-5 tornado!” or “A trained spotter has reported an EF-3 tornado moving toward the town of Pleasantville.” (A properly informed spotter won’t use such language.)

As for reporting tornado damage, most people–including me–aren’t intimately familiar with the nuances and complexities of the Enhanced Fujita scale. So leave it alone. Better to just describe the damage in general terms as light, significant, severe, homes completely swept away, trees uprooted, complete devastation, and so forth. Or if you want to speculate on the EF potential, make it clear that what you’re sharing is only your opinion. Saying, “This looks like it could receive an EF-2 rating,” or, “I’m guessing EF-3 damage here, but we’ll wait for the National Weather Office to make an official determination,” is different from stating definitively that “We’ve got EF-4 damage.” How do you know? Unless you’re a NWS damage assessment expert, you don’t. Your guess may prove to be true, but leave it out of print or off the airwaves until it has been established as fact.

The Bottom Line

It’s human nature to speculate on the strength and effects of something as singular, violent, visually striking, and impactful on a community as a tornado. Moreover, there’s nothing wrong with forming your personal opinion regarding which EF-scale rating a tornado might deserve, bearing in mind that you could very well be wrong. But if you’re a broadcast personality, reporter, or storm spotter, hold your thoughts to yourself. When it comes to information that’s relevant and truly helpful to the public, you’ll do well to heed the advice of Sergeant Friday in the old Dragnet TV series: The facts, please. Just give us the facts.