(often used as 'wintry showers'): When the air temperature is close to zero deg.C (either side), it is sometimes easier to use this shorthand term for showers producing soft hail, sleet, snow, 'sleety-rain' etc. Frowned upon by proper meteorologists but a useful term nonetheless. (However, we try to avoid it when the showers are much heavier, and are expected to give significant snowfall.)
WINTRY PRECIPITATION
Meaning of WINTRY PRECIPITATION in English
Weather and meteorology English vocabulary. Английский словарь погоды и метеорологии . 2012