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Cone of Silence
Fri Jan 23, 2004
Listen in RealAudio 
What does weather radar have to do with the TV show "Get Smart?" Why, the "Cone of Silence,"
of course. Hi, I'm Bryan Yeaton for The Weather Notebook.
If you watched that classic sixties sitcom, you might remember one of the recurring gags was a
see-through dome where secret agent Maxwell Smart could meet with his boss in confidence: the
Cone of Silence. The joke was the cone wasn't silent at all.
In real life, the cone of silence works perfectly. Where is it? Imagine you're a weather
radar, rooted to one spot, twirling around and scanning the horizon for storms. Now tilt your
head as high as it can go. You may notice there's a cone-shaped area right over you head that
you can't quite see. That's the cone of silence. The Doppler radar used by the National
Weather Service can tilt their receivers up to about 20 degrees above the horizon. This means
if a severe storm is ten miles away, the radar might see only the bottom half of it, although
it can still spot the rainfall below. And often, there's enough overlap in weather radar so
that the signals from one unit can be used to fill in the cone of silence from
another.
But sometimes the cone of silence leaves forecasters in the dark. That happened near Del Rio,
Texas, in May of 2001. A late-night thunderstorm brought a powerful downdraft that slammed
into the dome of the weather service radar, disabling it for weeks. We'll never know the
details of that downdraft, because it was obscured by the cone of silence. Certainly, Maxwell
Smart would understand.
Thanks to Bob Henson for today's silent story. The Weather Notebook is produced with support
from The National Science Foundation and Subaru - Driven By What's Inside. Special funding
comes from Davis, makers of the Car Chip: a black box for your car.
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