Tornado or straight-line winds; how do you know? - | WBTV Charlotte

Tornado or straight-line winds; how do you know?

CHARLOTTE, NC (WBTV) - A storm moves through your neighborhood.  It causes damage, but it's unknown whether the thunderstorm that moved through actually produced a tornado.  For a group of meteorologists with the National Weather Service, that's where their puzzle begins. 

After the storm, a team of two meteorologists will make preparations to go out and study the damage caused by the storm.  They will analyze maps of the area and talk to local Emergency Management officials.

Then they head to the damage site.

Tony Sturey, a Warning Coordination Meteorologist with the National Weather Service in Greenville-Spartanburg, says that while inspecting the damage he's trying to put together a puzzle.  "You're trying to piece together something that's very chaotic." 

To determine whether or not a storm was tornadic, meteorologists look at the damage patterns.  To help him visualize the storm, Sturey draws vectors of the damage on a map.  Divergent patterns are usually indicative of straight-line wind damage, while patterns showing circulation often point toward tornado damage.  He's quick to point out, however, that there are always exceptions.  "There are always outliers."  He adds that a storm can also cycle back and forth.  Some storms are obvious early, but others can be more difficult.

Along with their work at the damage site, they will also speak with any witnesses about what they saw and look at any pictures or videos that are available.  Once they make their conclusion in the field, they will report to a mobile command area or call in prelim info to weather service office.  Next the local weather service office will put out a Public Information Statement and eventually release a comprehensive report with their final findings.

If it is determined that a tornado did touch down, the damage is then compared to a set of about 30 damage indicators that engineers have studied.  It will take much stronger winds to knock over a mobile home than one made of brick.  By noting the strength of what was damaged, it is then classified using the Enhanced Fujita Scale, with an EF-0 being the weakest and EF-5 being the strongest.  It's important to note here that the tornado is ranked after the storm, and not during it.

One of the biggest myths is that a tornado sounds like a freight train.  Coming up later this week we'll set the record straight about this and other severe weather myths.

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