How do low-pressure areas and cyclones form?

Cyclogenesis is the broad term for the development and strengthening of cyclonic circulation in the atmosphere, encompassing various processes from microscale to synoptic scale. Different types of cyclones, such as tropical, extratropical, and mesocyclones, form through distinct mechanisms involving factors like latent heat, weather fronts, and atmospheric instability. Furthermore, some extratropical systems undergo explosive cyclogenesis, rapidly dropping in atmospheric pressure to create intense weather events.

What we know

• Cyclogenesis is an umbrella term for at least three different processes that result in the development of a cyclone at scales ranging from microscale to synoptic scale. [2]
• Tropical cyclones form as warm-core cyclones driven by latent heat from significant thunderstorm activity and require six main factors, including sufficiently warm sea surface temperatures. [2, 4]
• Extratropical cyclones form as waves along weather fronts before eventually occluding later in their life cycle as cold core cyclones. [2]
• Explosive cyclogenesis, or bombogenesis, involves a rapid central pressure decrease of 24 millibars or more in 24 hours, with the exact threshold being latitude dependent. [3]

Where to go next

• how it workedWhat triggers tropical cyclones to develop?
• a case in pointWhat happens during explosive cyclogenesis?
• compared withWhat is an anticyclone and how do high-pressure areas form?
• the bigger pictureWhat characteristics define a subtropical cyclone?
• what followedHow do tornadoes originate from mesocyclones?
• an unexpected connectionHow can winter maritime storms pack winds as fierce as tropical hurricanes?Although bomb cyclones form through entirely different extratropical mechanisms than tropical storms, they can still produce hurricane-force winds ranging from 74 to 95 mph.

Sources

• [1]cyclogenesis (Wikidata Q245472) · CC0 1.0
• [2]Cyclogenesis · CC BY-SA 4.0
• [3]Explosive cyclogenesis · CC BY-SA 4.0
• [4]Tropical cyclogenesis · CC BY-SA 4.0
• [5]Subtropical cyclone · CC BY-SA 4.0