What is an extratropical cyclone?

Extratropical cyclones are large atmospheric storms that form in mid-latitude regions along zones of strong temperature contrasts. Driven by upper-level Rossby waves and guided by the subtropical jet stream, these synoptic-scale low-pressure systems develop weather fronts over a two-to-six-day life cycle. Unlike tropical cyclones, extratropical storms eventually occlude into cold-core systems.

What we know

• Extratropical cyclones originate as waves within baroclinic zones characterized by strong temperature contrasts in mid-latitude regions. [2]
• An extratropical cyclone's movement is guided by the subtropical jet stream over a typical life cycle lasting two to six days. [2]
• Extratropical cyclones operate on a synoptic horizontal scale of 1,000 kilometers or more and are driven by atmospheric Rossby waves. [3]
• Extratropical cyclones occlude into cold-core systems late in their life cycle as cold air masses undercut warmer air. [2]
• Cyclonic systems are capable of transitioning between tropical, subtropical, and extratropical phases. [2]

Where to go next

• what caused itHow do jet streams steer atmospheric storms?
• how it workedHow do weather fronts form during cyclogenesis?
• what followedWhat occurs during extratropical occlusion?
• compared withHow do mid-latitude depressions compare to tropical cyclones?
• the bigger pictureWhat is synoptic scale meteorology?
• an unexpected connectionCan a tropical storm transform into an extratropical cyclone?Cyclones are dynamic weather systems capable of transitioning between warm-core tropical, subtropical, and cold-core extratropical phases over their lifespan.

Sources

• [1]cyclone (Wikidata Q79602) · CC0 1.0
• [2]Cyclone · CC BY-SA 4.0
• [3]Synoptic scale meteorology · CC BY-SA 4.0
• [4]2026–27 South Pacific cyclone season · CC BY-SA 4.0
• [5]Cyclone Arnab · CC BY-SA 4.0