Extratropical

{
  "id": "MLC-T-MET-000921",
  "term": "Extratropical",
  "field": "Meteorology and atmospheric science",
  "definitions": [
    "Describing atmospheric phenomena that occur outside of the tropics, generally poleward of 30 degrees latitude in both hemispheres. This includes weather systems such as mid-latitude cyclones, frontal zones, and associated precipitation. These systems are driven by horizontal temperature gradients and the Coriolis effect, contrasting with tropical systems that derive energy from latent heat release.",
    "A term used in advisories and tropical summaries to indicate that a cyclone has lost its \"tropical\" characteristics. The term implies both poleward displacement of the\ncyclone and the conversion of the cyclone's primary energy source from the release of latent heat of condensation to baroclinic (the temperature contrast between warm and cold air\nmasses) processes. It is important to note that cyclones can become extratropical and still retain winds of hurricane or tropical storm force."
  ],
  "references": [
    "NWS Glossary"
  ],
  "url": "https://mlchart.com/terminology/meteorology/extratropical/"
}