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Posted at 03:58 PM ET, 07/02/2012

Lightning gone wild during Washington D.C.’s derecho


A still shot of lightning flashes captured by the Washington, D.C. Lightning Mapping Array shown atop a radar (rain reflectivity) image. (Scott Rudlosky)
The wind stole the show, but the second most striking feature of Friday night’s derecho was the vivid, almost continuous display of lightning.

The amount of atmospheric energy for this event was through the roof, priming the sky for the lightning spectacle.

It turns out the coverage and intensity of lightning was measured and mapped via a local network of 10 sensors known as the Washington, D.C. Lightning Mapping Array (DCLMA).

Watch the lightning flare up as the derecho blasts through the metro region in the animation below - visualizing DCLMA data.

Scott Rudlosky, a physical scientist with NOAA who works with the lightning data, said it can reveal certain storm characteristics not apparent in conventional radar.

“[Something] the lightning data shows well, which tends to mix out on radar, is the location of the strongest convection within the main line,” he said.

In the the above animation, the lightning flash markers unveil the explosive development of convection after the storms cross the Appalachians and encounter the hot, unstable environment around D.C.

As impressive as the animation is, it only captures about 25 percent of the lightning from the storm Rudlosky said (the actual network captures a lot more).

He called the derecho’s lightning show “one of the largest I have seen in D.C.”

Just a week before the derecho, he blogged about the lightning associated with the microburst storm that rocked parts of Montgomery county, the District, and northern Prince Geoge’s county.


Comparison of lightning radiation detected by the Washington, D.C. Lightning Mapping Array, between the June 22 microburst and June 29 derecho in Washington, D.C. from a network of 10 local lightning sensors. ( Washington, D.C. Lightning Mapping Array )
The image above shows a comparison of the two events. You can see how lightning reached extreme intensity during both events, but was more widespread in the derecho. The units shown are a measure of the density of very high frequency (VHF) radiation sources detected by the network. In both images, levels reach the top of the scale.

Established in 2006, Washington, D.C. Lightning Mapping Array (DCLMA) is a joint demonstration project involving NASA, NOAA, New Mexico Tech (the inventors of the lightning detector stations used), and a number of local sponsors.

What did you make of the lightning during the derecho? Do you notice any interesting or unusual qualities?

By  |  03:58 PM ET, 07/02/2012

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