Primary depression

{
  "id": "MLC-T-MET-008146",
  "term": "Primary depression",
  "field": "Meteorology and atmospheric science",
  "definition": "An extratropical cyclone identified on a synoptic chart by at least one closed isobar, which is not part of a broader family of cyclones. It moves independently and is the main low-pressure system in a region, as opposed to a secondary depression that forms on its trailing fronts. A primary depression may have multiple secondary lows developing within its circulation as the system matures and occludes.",
  "url": "https://mlchart.com/terminology/meteorology/primary-depression/"
}