Dear Scotsbard,

I'll give you what the paper says about yesterday's twisters:

"[quoting Skip Ely, a meteorologist with the National Weather Service in Fort Worth]" . . . yesterday's twister was what forecasters call a 'cyclic storm'."

"It means that a tornado develops and dissipates, and another tornado develops and dissipates nearby, and sometimes the process will go on four or five times."

A tornado is a balance beween downdrafts and updrafts, he said. Sometimes, a downdraft will wrap around the updraft and choke off the supply of warm, moist air, which causes the tornado to weaken and dissipate.

"But the parent air circulation aloft in the middle to upper levels of the storm remains, and a new tornado sometimes develops in the new updraft of the storm complex," he said. The new tornado frequently moves east or southeast of the first tornado."

The paper also says that radar images show the tornado that struck downtown Ft. Worth developed suddenly northwest of the city center and curved eastward. It zigzagged through downtown, and began to head east after hitting the Clear Fork of the Trinity River. The twister appeared to break up in the vicinity of N. Riverside Drive along Interstate 30, but it was quickly replaced by a separate but related tornado that swept through southwest Arlington and Grand Prairie, continuing on a southeast track until it dissipated over DeSoto.