High and Low Lightning
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Have you ever wondered why some thunderstorms keep their lightning high in the clouds while others drop bolt after bolt to the ground? Meteorologists have wondered the same thing for years. It's only now though that they have the tools to start to figure it out. Hi, I'm Dave Thurlow from the Mount Washington Observatory and this is the Weather Notebook.

Multiple cloud-to-ground and cloud-to-cloud lightning strokes observed during night-time thunderstorm. NOAA Photo Collection

Cloud to ground strikes are the ones that can zap kites, scare dogs and even kill people. But, thunderstorms vary in how many cloud to ground strikes or "CG's" as they're called, they can produce. Since the 1980s we've been able to count CG's across the country through a network of special antennas. You might see these reports in a lightning strike map on your local weathercast. But, what about the lightning that stays up in the clouds?

It's much harder to locate these intracloud or "IC" flashes. But, a few studies have used special equipment to track ICs and two NASA satellites are now watching for ICs. Certain types of thunderstorms produce a lot more lightning up above then down below. This includes the giant storm clusters that cause the flooding in the midwest almost every year. On the other hand some of the smaller severe storms that drop very little rain can still produce a lot of cloud to ground lightning.

Starting this month in the high plains a summer-long research project will document these low precipitation storms. But, whatever the thunderstorm type, it's always best to remember lightning safety. Be sure to take shelter indoors whenever thunder follows lightning by less than thirty seconds. Our writer today is Bob Hensen from Boulder, Co. He has a masters degree in meteorology. He's a writer, stormchaser and a frequent contributor to our show.