tropical cyclone scales tropical cyclones officially ranked tropical cyclone scales according maximum sustained winds tropical cyclone basin located scales classifications officially meteorological agencies monitoring tropical cyclones alternative scales exist accumulated cyclone energy power dissipation index hurricane severity index tropical cyclone form classified categories saffir simpson hurricane scale tropical cyclones ranked scale india uses different scale assess maximum sustained winds tropical cyclone forecast center reunion uses scale covers fiji use australian tropical cyclone intensity scale definition sustained winds recommended weather agencies minute average height saffir simpson hurricane scale based wind speed measurements averaged minute period surface scale applies minute averaging period australian scale based second wind gusts maximum sustained winds averaged minute interval direct comparisons basins difficult basins tropical cyclones named sustained winds hit mph background tropical cyclones defined warm non frontal cyclones develop tropical subtropical waters organized atmospheric convection definite cyclonic surface wind circulation classified wind speeds located circulation centre ranked tropical cyclone scales scale particular tropical cyclone depends basin system located example saffir simpson hurricane wind scale australian tropical cyclone intensity scales scales rank tropical cyclones maximum sustained winds observed measured estimated techniques period minutes atlantic eastern central pacific tropical cyclones occur east anti officially monitored national_hurricane_center region tropical cyclone defined warm non frontal cyclone develops tropical subtropical waters organized atmospheric convection closed defined circulation centre region defines subtropical cyclone non frontal low pressure system characteristics tropical extratropical cyclones classifications met warning centers classify system tropical subtropical depression minute sustained winds estimated measured mph system intensify minute sustained winds mph called tropical subtropical storm assigned tropical system intensify winds estimated measured greater mph called hurricane classified saffir simpson hurricane wind scale lowest classification category hurricane winds mph hurricane intensify rated category hurricane winds mph system category hurricane winds mph considered major hurricane warning centers category hurricane winds mph category hurricane winds mph originally created wind speed storm surge relationship wind speed storm surge necessarily definite scale changed saffir simpson hurricane wind scale based entirely wind speed increasing scale correspond stronger winds rankings absolute terms effects lower category storms inflict greater damage higher category storms depending factors local terrain population density total rainfall instance category strikes major urban area likely damage large category hurricane strikes rural region fact tropical systems hurricane strength produce significant damage human casualties especially flooding landslides historically term great hurricane describe storms possessed winds mph large caused large amounts destruction term fell introduction saffir simpson scale early 1970s minor change scale ahead hurricane season wind speeds categories eliminate rounding errors occurred previous seasons hurricane wind speeds mph tropical cyclones occur anti officially monitored tokyo region tropical cyclone defined non frontal scale cyclone originating tropical sub tropical waters organized convection definite cyclonic surface wind circulation lowest classification tropical depression minute sustained winds mph tropical depression intensify named classified tropical storm winds speeds mph system continue intensify classified severe tropical storm winds speeds mph highest classification typhoon committees scale typhoon winds speeds greater mph divide typhoon category domestic purposes divides typhoon category categories minute maximum wind speed mph assigned strong typhoon category strong typhoon wind speeds mph violent typhoon wind speeds mph greater divide typhoon category categories assigning maximum wind speed mph typhoon category severe typhoon wind speeds mph super typhoon winds mph introduced term super typhoon systems winds greater mph addition nation united_states joint typhoon warning centre monitors basin issues warnings significant tropical cyclones warnings use minute sustained wind speed compared saffir simpson hurricane wind scale use scale intensity classifications basin classifications typhoon super typhoon addition scale chinese uses scale english tropical cyclone develops monitored region tropical cyclone defined non frontal scale cyclone originates tropical subtropical waters organized convection definite cyclonic surface wind circulation lowest official classification depression minute sustained wind speeds mph depression intensify deep depression winds mph system classified cyclonic storm assigned develop gale force wind speeds mph severe cyclonic storms storm force wind speeds mph severe cyclonic storms hurricane force winds mph extremely severe cyclonic storms hurricane force winds mph highest classification hurricane force winds mph historically system classified depression area barometric pressure low compared surroundings classifications historically include cyclonic storm winds exceed force scale cyclone winds force scale tropical cyclones classified categories depression deep depression cyclonic storms severe cyclonic storms change introduce category severe cyclonic storm core hurricane winds tropical cyclones wind speeds mph categories severe cyclonic storm super cyclonic storm introduced severe cyclonic storm core hurricane winds category eliminated modification intensity scale took place calling system minute maximum sustained wind speeds mph extremely severe cyclonic storm united_states joint typhoon warning centre monitors basin issues warnings significant tropical cyclones behalf warnings use minute sustained wind speed compared saffir simpson hurricane wind scale regardless intensity basin labels systems tropical cyclones south western indian ocean tropical cyclone develops africa monitored tropical cyclone centre region tropical disturbance defined non frontal scale low pressure area originating tropical sub tropical waters organized convection definite cyclonic surface wind circulation average wind speed estimated exceeding knots tropical disturbance generic term non frontal area low pressure organized convection definite cyclonic surface wind circulation system estimated wind speeds knots mph system designated tropical depression subtropical depression reaches wind speeds knots mph tropical depression reach wind speeds knots mph classified moderate tropical storm assigned mauritius madagascar matter strong subtropical system basin designated subtropical depression named storm intensify reach winds speeds knots mph classified severe tropical storm severe tropical storm designated tropical cyclone reaches wind speeds knots mph tropical cyclone intensify reach wind speeds knots mph classified intense tropical cyclone intense tropical cyclone highest category south west indian ocean tropical cyclone scale winds knots mph tenth tropical cyclone committee held recommended intensity classifications changed ahead tropical cyclone season specifically decided classifications moderate tropical depression severe tropical depression changed moderate tropical storm severe tropical storm change implemented ahead tropical cyclone season united_states joint typhoon warning centre monitors basin issues warnings significant tropical cyclones behalf warnings use minute sustained wind speed compared saffir simpson hurricane wind scale regardless intensity basin labels systems tropical cyclones australia fiji tropical cyclones occur east officially monitored tropical cyclone warning centres run new_zealand indonesia dan national_weather_service run region tropical cyclone defined non frontal low pressure system scale develops warm waters definite organized wind circulation minute sustained wind speeds mph greater near centre definition met centres system start use australian tropical cyclone intensity scale measures tropical cyclones category system based minute maximum sustained winds category tropical cyclone estimated minute sustained wind speeds mph category tropical cyclone estimated minute sustained wind speeds mph system category tropical cyclone reclassified severe tropical cyclone wind speeds mph category severe tropical cyclone winds mph maximum rating category severe tropical cyclone winds mph systems tropical cyclone strength terms including tropical low tropical depression tropical disturbance defined non frontal system scale originating tropics persistent enhanced convection indication circulation tropical depression tropical low disturbance defined circulation central position estimated maximum minute average wind speed mph near centre numbers systems potential develop tropical cyclone persist cause significant impact life property area responsibility analysed previous hours australian tropical cyclone intensity scale introduced ahead cyclone season united_states joint typhoon warning centre monitors basin issues warnings significant tropical cyclones behalf warnings use minute sustained wind speed compared saffir simpson hurricane wind scale regardless intensity basin labels systems tropical cyclones alternative scales scales officially organizations example scale index measures destructive potential storm surge works scale ranges having highest destructive potential accumulated cyclone energy ace agencies express activity individual tropical cyclones tropical storm strength entire tropical cyclone seasons calculated taking squares estimated maximum sustained velocity active tropical storm wind speed knots higher hour intervals numbers usually divided unit ace use index unit assumed squared ace wind speed referred power dissipation index hurricane severity index scale rates severity types tropical subtropical cyclones based intensity size wind fields point scale points tropical cyclone intensity points wind field size points awarded sliding scale majority points reserved hurricane force greater wind fields comparisons basins terminology tropical cyclones differs region summary classifications official warning centres worldwide
Tropical cyclone scales