Roll

{
  "id": "MLC-T-MET-008601",
  "term": "Roll",
  "field": "Meteorology and atmospheric science",
  "definition": "A type of horizontal, tube-shaped cloud associated with the leading edge of a thunderstorm gust front or a cold front. This cloud, formally an arcus cloud, is completely detached from the base of the parent cumulonimbus cloud, distinguishing it from a shelf cloud. A roll cloud appears to be rolling about its horizontal axis as it moves across the sky, driven by the outflow of cold air.",
  "see_also": [
    "Pitch",
    "Yaw",
    "ship motion"
  ],
  "url": "https://mlchart.com/terminology/meteorology/roll/"
}