Weather or Not | The fearsome flash

A look at lightning, a phenomenon that's treacherous, entrancing and perfectly natural.

Posted: June 18, 2007

By the time a neighbor spotted him, Zachary Yizzi's shirt was on fire. When the paramedics arrived, the 14-year-old had no pulse.

Lightning struck Zachary on his Cherry Hill street Tuesday afternoon as particularly powerful thunderstorms fired the atmosphere with electricity. Peco Energy recorded 46,000 strikes that day in South Jersey and Southeastern Pennsylvania.

It was a tragic incident, a parent's nightmare that underscores the hazards of lightning as we enter the peak lightning season.

Yet truth be told, I've taken more than one risk during electrical storms, both as a teenager and as a well-seasoned adult.

I have always found lightning at once fascinating and frightening, and still feel a sense of awe watching the brilliant, jagged lines exploding from the sky with strobelike flashes incandescently turning night into day.

As Benjamin Franklin certainly would have agreed, lightning is dramatic and irresistible.

So what is it?

Essentially, lightning is a massive spark of static electricity. It is set off by the attraction between negative and positive charges - either among clouds (the kind to watch) or between clouds and the ground (watch out).

The incredible heat generated by lightning - a bolt can sear surrounding air to 50,000 degrees Fahrenheit - helps set off the shock wave we call thunder. It is impossible to have lightning without thunder, and vice versa.

Cloud-to-ground lightning, sometimes in those spectacular forks and zigzags, comes when negative charges in the clouds find their positive opposites near the ground.

Since the storms that rolled through Tuesday were particularly electrified, the rising air currents within them must have encountered generous amounts of ice in the high atmosphere.

Ice is essential to lightning, says Ted Mansell, a scientist at the University of Oklahoma.

Without ice, storms have trouble generating electricity. Air in a storm moves up and down violently, causing collisions among moving ice particles. Some tropical-storm remnants can wring out heavy rains but fail to kick off thunderstorms because the air is too warm for ice to form.

"The lightning is primarily a discharge that builds up from these ice collisions," says Mansell, who works with the Cooperative Institute for Mesoscale Meteorological Studies, a partnership between the university and the National Oceanic and Atmospheric Administration.

Mansell is researching ways to use real-time lightning data in forecast models in the hope of making thunderstorm forecasts more precise in timing and location.

During the ice collisions, electrical charges become separated. Positively charged ice particles head to the top of the thunderstorm; those with negative charges move down.

The overwhelming majority of lightning flashes, 60 to 95 percent, occur from cloud to cloud, high in the sky.

Cloud-to-ground lightning, the kind more likely to get our attention, results when the negatively charged ice particles in a storm are attracted to their positive opposites near the ground.

That kind is extremely dangerous to those of us below. Of course, the odds that you'll get hit by lightning are minuscule - about 280,000 to 1 in any given year - and relatively simple precautions can make them even smaller.

At any given instant, 2,000 or so storms are cooking on the planet, accompanied by about 100 lightning flashes a second. Obviously, only a tiny percentage of them injure or kill human beings - an average of 54 deaths per year from lightning in the United States, according to NOAA data.

But it does happen.

Zachary Yizzi, the Cherry Hill teenager, remains in stable condition at Temple University Hospital's Burn Center. A few years back, a Chester County man was struck and killed on a golf course.

Bob Stauber, a National Weather Service meteorologist in Mount Holly, noted that lightning can strike even when a thunderstorm is miles away. Mary Ann Cooper, an expert in lightning injuries, says the old rules about what to do if you're outside and hear thunder are obsolete.

"No place outside is safe when thunderstorms are in the area," says Cooper, a professor of emergency medicine at the University of Illinois.

Assuming we have the good luck and good sense to be inside, odds are that when we hear the ominous rumble of thunder, instinctively we look to the window - and not usually out of fear.

For high drama, lightning holds a special place, a fiery reminder that we are connected to something larger and electrifying.


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Contact staff writer Anthony R. Wood at 610-313-8210 or twood@phillynews.com.

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