A thunderstorm with hail diameter greater than 12 millimeters inches) but less than 19 millimeters (0.75 inches) and surface winds between 40 and 57 miles per hour (64 and 92 kilometers per hour).
APPROACHING-SEVERE THUNDERSTORM
Meaning of APPROACHING-SEVERE THUNDERSTORM in English
Weather and meteorology English vocabulary. Английский словарь погоды и метеорологии . 2012