Gray, dark clouds with no clearly defined base which are associated with continuous precipitation that may or may not reach the ground. The clouds are several thousand feet thick and will completely block the Sun. Their precipitation may consist of snow, sleet, rain, or drizzle, but not hail (since there is no convection). [See also stratus.]
NIMBOSTRATUS (NS)
Meaning of NIMBOSTRATUS (NS) in English
Weather and meteorology English vocabulary. Английский словарь погоды и метеорологии . 2012