Abstract
Meteorological conditions leading to the crash of an airliner short of the runway of a New York airport were studied. Thunderstorm downdrafts much stronger than those measured on the 1946–47 Thunderstorm Project were found. These exceptional downdrafts have been designated as “downbursts.” The violent cloud systems that produce downburst cells can be identified in the form of forward extensions of radar echoes designated as “spearhead echoes” which move with unusual speed. The development of downburst cells appears to he tied in with overshooting tops of clouds at the anvil level.
