A shocking side to the blizzard of '93.

The mammoth blizzard that buried the East Coast with snow in mid-March also generated record-breaking amounts of lighting. Within two days, sensors along the storm track detected more than 59,000 flashes from cloud to ground, reports Richard E. Orville of Texas A&M University in College Station.

The blizzard developed over Texas and the Gulf of Mexico and then rolled straight up the East Coast between March 12 and 14. It pounded Florida with heavy winds and tornadoes and dropped record snowfall farther north, causing 200 deaths.

Compared with summer storms, winter blizzards do not normally create much lighting. But sensors recorded a surge in lightning strikes as the blizzard gained strength, peaking at 5,100 flashes per hour on March 13, Orville reports in the July 9 GEOPHYSICAL RESEARCH LETTERS. That exceeds the highest flash rate ever reported in the scientific literature for any storm, summer or winter--a record that stood at 3,300 flashes per hour. Orville notes, however, that he has seen unpublished data on summer storms with 9,100 flashes per hour.

Researchers have yet to figure out why the March blizzard sparked so many bolts. Most winter storms lack the strong vertical air currents that build tremendous electric charges in clouds, but this one clearly did not fit the usual pattern.