Definition
Long, parallel rows of cumulus clouds that form along the axis of the wind, spaced roughly evenly apart. They develop when convective thermals rise in organized rolls of circulating air, with cloud forming along the rising bands and clear air along the sinking bands between them.
Plain English
Lines of puffy clouds lined up like rows on a farm field, all running in the same direction as the wind. Between each cloud line is a strip of clear sky.
Context Anchor
Seen in weather discussions, cross-country planning, and in flight when rows of cumulus clouds stretch across the sky in the same direction.
Derivation
Called 'streets' because the clouds line up in long, parallel rows that look like streets running across the sky.
Why Pilots Care
They mark reliable lift for gliders and indicate consistent surface winds, while also helping pilots anticipate areas of possible turbulence.
Grounding Statement
On a sunny day with steady wind, warm air rising from the ground organizes itself into parallel rolling tubes, with clouds forming along the tops of the rising sides.
Intuition Check
Do not read “streets” as actual paths a pilot should follow without judgment. Cloud streets are visual signs of organized rising and sinking air, not marked airways or guaranteed smooth routes.
Example Sentence 1
We spotted cloud streets stretching across the valley and followed them north, riding the lift the whole way.
Example Sentence 2
During the morning briefing the instructor pointed out the cloud streets on the satellite image to show the expected wind direction.