Inmeteorology, acycloneis a large scaleair massthat rotates around a strong center of lowatmospheric pressure.[1][2]Cyclones are characterized by inwardspiralingwindsthat rotate about a zone oflow pressure.[3][4]The largest low-pressure systems arepolar vorticesandextratropical cyclonesof the largest scale (thesynoptic scale). Warm-core cyclones such astropical cyclonesandsubtropical cyclonesalso lie within the synoptic scale.[5]Mesocyclones,tornadoes, anddust devilslie within smallermesoscale.[6]Upper level cyclones can exist without the presence of a surface low, and can pinch off from the base of thetropical upper tropospheric troughduring the summer months in theNorthern Hemisphere. Cyclones have also been seen on extraterrestrial planets, such asMars,Jupiter, andNeptune.[7][8]Cyclogenesisis the process of cyclone formation and intensification.[9]Extratropical cyclonesbegin as waves in large regions of enhanced mid-latitude temperature contrasts calledbaroclinic zones. These zones contract and formweather frontsas the cyclonic circulation closes and intensifies. Later in their life cycle, extratropical cyclonesoccludeas cold air masses undercut the warmer air and become cold core systems. A cyclone's track is guided over the course of its 2 to 6 day life cycle by the steering flow of the subtropicaljet stream.

Weather fronts mark the boundary between two masses of air of differenttemperature,humidity, anddensities, and are associated with the most prominentmeteorological phenomena. Strong cold fronts typically feature narrow bands ofthunderstormsandsevere weather, and may on occasion be preceded bysquall linesordry lines. Such fronts form west of the circulation center and generally move from west to east;warm frontsform east of the cyclone center and are usually preceded bystratiformprecipitationandfog. Warm fronts movepolewardahead of the cyclone path. Occluded fronts form late in the cyclone life cycle near the center of the cyclone and often wrap around the storm center.

Tropical cyclogenesisdescribes the process of development of tropical cyclones. Tropical cyclones form due to latent heat driven by significant thunderstorm activity, and are warm core.[10]Cyclones can transition between extratropical, subtropical, and tropical phases. Mesocyclones form as warm core cyclones over land, and can lead totornadoformation.[11]Waterspoutscan also form from mesocyclones, but more often develop from environments of high instability and low verticalwind shear.[12]In the Atlantic and the northeastern Pacific oceans, a tropical cyclone is generally referred to as ahurricane(from the name of the ancient Central American deity of wind,Huracan), in the Indian and south Pacific oceans it is called a cyclone, and in the northwestern Pacific it is called atyphoon.[13]The growth of instability in the vortices is not universal. For example, the size, intensity, moist-convection, surface evaporation, the value of potential temperature at each potential height can affect the nonlinear evolution of a vorte.