Occasionally I write a blog post on something other than charity auctions. This is one such post.
But today, I’m ranting. And it’s not on auctions.
Since moving to the Washington, DC area, I’ve been annoyed with what I’ve perceived to be inaccurate weather reports around tornadoes. It’s the tornado warning versus watch lingo.
Announcers will say, “We’ve got a tornado warning in effect,” when the weather suggests they meant to say, “We’ve got a tornado watch in effect.”
- A watch means the conditions are ripe for a tornado to form. In effect, we should be watching the clouds for a tornado because one could appear.
- A warning is more serious. In Kansas vernacular, it means grab the dog and take cover because a tornado is ripping through the area.
“Reporters get the definitions mixed up out here,” a fellow Midwestern once agreed.
About three weeks ago while running errands, I heard another on-air reporter confuse the lingo. This time I decided to correct the language. I sent an email to the on-air reporter inquiring as to whether she was using the proper terminology. She promptly emailed back, “Here’s what the National Weather Service sent us.”
The bulletin she had from the NWS confused me.
Here it is:
BULLETIN – EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 201 PM EDT SUN AUG 21 2011
THE NATIONAL WEATHER SERVICE IN STERLING VIRGINIA HAS ISSUED A
* TORNADO WARNING FOR…
NORTHEASTERN ANNE ARUNDEL COUNTY IN CENTRAL MARYLAND…
* UNTIL 230 PM EDT
* AT 200 PM EDT…NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR FORT
SMALLWOOD STATE PARK…MOVING EAST AT 20 MPH.
* LOCATIONS IMPACTED INCLUDE..
Remember: A warning means that a tornado is occurring or imminent. But the language in this bulletin said, “…severe thunderstorm capable of producing a tornado…”
Capable doesn’t mean “sure thing.” It means maybe … perhaps … it could.
What was going on here?
I emailed the National Weather Service for clarification. It took two emails and a phone call, but here’s what I learned.
Tornado warnings are issued in two ways: by eyewitness or by Doppler analysis.
In the Midwest, most tornado warnings are issued after someone sees the funnel.
Because of long sightlines and few trees, it’s relatively easy to see a tornado approaching. Warning bulletins sound like, “Kansas Highway Patrol has spotted a tornado in Butler County heading southeast towards XYZ… “
But along the East coast, tornado warnings are most often issued by Doppler analysis.
Because of the hilly terrain and trees in the Washington, D.C. area, tornadoes are difficult to see. In addition, they tend to be wrapped in rain, so the storm itself hides the approaching funnel.
To compensate, meteorologists watch atmospheric conditions from their computer screen to see if a pattern of rotating swirling clouds emerges. If it does, they issue a tornado warning. The resulting warning bulletin sounds like, “The National Weather Service Doppler radar indicated…”
The key is to listen to the report. How was the tornado identified?
If the reporter says, “Montgomery County law enforcement reported a tornado traveling along I-270 …” it means that the funnel has been seen by human eyes. It exists.
But if the reporter reads, “The National Weather Service Doppler radar indicated…” (Or as it does in the above bulletin, “National Weather Service Doppler radar indicated a severe thunderstorm …”), it means the meteorologist’s computer analysis suggests a tornado exists.
I didn’t know the difference … did you?
Glad we’ve got this cleared up.