Author's Note: The following report has not been subjected to the scientific peer review process.

On Friday evening, July 28th, a fierce thunderstorm affected central 
Greenville and Spartanburg counties.  The storm was unusual in that it 
drifted slowly west, dropping torrential rain (2.97 inches at our office). 
Hail fell for nearly 30 minutes at the airport, reaching the size of dimes 
on two occasions.  The storm also had nearly continuous cloud-to-ground 
lightning.  In addition to the several trees which were struck at the 
GSP airport, the main runway was also hit.  Lightning blasted an 18 inch 
diameter hole in the runway, temporarily closing the airport.

Figure 1.  A series of four images showing lightning damage to trees at 
the Greenville - Spartanburg International Airport, caused by a severe 
thunderstorm on 28 July 2000.  From left to right, a tree in the long-term 
parking lot, along with a close-up of the same tree.  Looking up the trunk, 
the scar caused by the path taken by the lightning along the bark of the 
tree.  Another tree damaged by lightning was just a few feet away.

A few pictures of the trees hit by lightning are provided above.  Click 
on the image to see a larger picture.  The first three pictures are of 
the same tree.  This is a wonderful illustration of how lightning works. 
The lightning strike followed the conductive, living outer layer of the 
tree.  While bark was knocked off in a 4 or 5 inch width along the path, 
a much smaller channel was cut in the wood of the tree.  The width of an 
average lightning channel is somewhere between that of a pencil and a 
human finger.  Thus, the deeper gouge in the tree was that of the lightning 
channel itself!