Formation of expanded fields of stratocumulus clouds due to very light winds at the surface combined with little instability as can be seen in the weather sounding. Typically, these form after rain but no rain was observed on the day but the moist NE wind blowing at the time usually cause cloudy skies over the Islands. According to the visible satellite image analysis and the surface pressure chart, it seemed that the tail-end of a cold front was the trigger for such cloud formation as both cumulus and stratocumulus clouds were observed. The first thumbnail is another view of the dark bases of stratocumulus clouds and cumulus clouds formed on the day.