In the context of weather patterns, stormy weather with clouds and precipitation is usually indicated by **low air pressure**. Low air pressure is often associated with unsettled weather conditions, leading to the formation of clouds, precipitation such as rain or snow, and potentially stormy conditions.
Conversely, high air pressure typically brings about more stable weather conditions with clear skies and lower chances of precipitation. Therefore, when you observe low air pressure on a weather map or in a forecast, it is likely an indication of impending stormy weather characterized by clouds and precipitation.