Late-May 1998 Tornado Outbreak and Derecho - Northeastern North America Tornado Outbreak

Northeastern North America Tornado Outbreak

That afternoon, as the derecho dissipated, the outflow boundary moved into a very warm and unstable airmass which was in place (CAPE was above 2400 J/kg). Thunderstorms developed along this boundary and quickly became severe. One particularly severe thunderstorm which later went on to produce an F3 tornado in Mechanicville, NY developed at 4:02 pm. At 4:12 pm, the storm shows strong rotation with 64+ kt (33+ m/s) winds at 5,000 feet (1,500 m) in the mesocyclone. At 4:15, this storm produced 1 inch (25 mm) hail and a 52 mph (23 m/s) wind gust. At 4:17 pm, rotation increases, and at 4:20 pm the storm produced 1+3⁄₄ inches (44 mm) hail. At 4:22 pm, Albany Doppler radar shows a strong and deep TVS, with 105+ kt winds. This is also the same time a tornado is reported on the ground.

The most destructive tornado of the day tore through Mechanicville and the adjacent town of Stillwater. It caused major damage to the town's old industrial section located on Route 4 and 32 along the Hudson River. One of the two historic smokestacks (visible from 2 miles (3.2 km) away) was knocked down by the tornado. In 2005, the other smokestack and the conjoined building were bulldozed. The tornado was rated F3 on the Fujita scale.

Several other tornadoes touched down across New York and Pennsylvania with one of the tornadoes causing a fatality in the Salisbury, Pennsylvania area. Another tornado caused major damage to the town of Lyons while another caused major damage around the Binghamton Metro Area; TV station WIVT sustained heavy damage which forced them to be off the air for several months. Activity ceased late in the evening across the southeastern portion of Pennsylvania. A total of 41 tornadoes were confirmed during the post-derecho outbreak. In total, 1 was killed, dozens injured, and damages for the outbreak were at least $100 million.