Cloud Streets

Via Pink Tentacle. According to Wikipedia, cloud streets are

rows of cumulus or cumulus-type clouds aligned parallel to the low-level wind.

The most favorable conditions for their formation occur when the lowermost layer of air is unstable, but is capped by an inversion -by a stable layer of air. This often occurs when upper air is subsiding, such as under anticyclonic conditions, and is also frequently found when radiation fog has formed overnight. Convection occurs below the inversion , with air rising in thermals below the clouds and sinking in the air between the streets.