Roll cloud

{
  "id": "MLC-T-MET-002354",
  "term": "Roll cloud",
  "field": "Meteorology and atmospheric science",
  "definitions": [
    "A low, horizontal, tube-shaped arcus cloud that appears to roll about its horizontal axis. It forms along the leading edge of a thunderstorm outflow or a cold front, detached from the main cloud base. This cloud type is distinct from a shelf cloud, which is attached to the base of the parent cloud.",
    "A low, horizontal tube-shaped arcus cloud associated with a thunderstorm gust front (or sometimes with a cold front). Roll clouds are relatively rare; they are completely detached from the thunderstorm base or other cloud features, thus differentiating them from the more familiar shelf clouds. Roll clouds usually appear to be \"rolling\" about a horizontal axis, but should not be confused with funnel clouds."
  ],
  "see_also": [
    "Rotor cloud",
    "morning glory"
  ],
  "references": [
    "NWS Glossary"
  ],
  "url": "https://mlchart.com/terminology/meteorology/roll-cloud/"
}