pacific hurricane season pacific hurricane season fifth active season record active season terms season officially started eastern pacific june central pacific lasted november dates conventionally period year tropical cyclones form northeastern pacific_ocean bounds slightly exceeded hurricane alma formed hurricane alma earliest tropical cyclone basin satellite era began strongest october eastern pacific hurricane record overall impact season minimal tropical storm rachel mexico brought rain united_states brought light showers california season summary eastern hurricane season active terms number storms attained tropical storm intensity accumulated cyclone energy tropical cyclones year developed westward moving african tropical waves season established tropical storm records basin marked strong hurricanes named tropical cyclones seven record established pacific hurricane season years later long term average sixteen named storms twice average previous record reached hurricane intensity douglas aka rachel simon reach hurricane strength hurricanes reached category intensity higher saffir simpson hurricane scale strongest observed area alma earliest named tropical cyclone eastern pacific ocean east west eastern pacific produced tropical depressions reach tropical storm status exception marie polo systems developed east baja california favored area tropical cyclogenesis development tropical cyclones moved west northwest track dissipated cool waters affecting land rachel system landfall addition tropical storm formed eventually crossed dissipating storms hurricane alma tropical wave emerged africa april moved atlantic crossed northern south_america entered pacific_ocean convection started increase wave south panama wave moved westward continued better organized days wave organized designated tropical depression tropical depression moved slowly northwest strengthening slowly easterly vertical wind shear depression upgraded tropical storm alma storm quickly strengthened vertical wind shear relaxed near hurricane force morning hurricane alma reached peak intensity early maximum sustained winds mph hurricane entered area southwesterly wind shear caused upper level ridge high pressure increasing vertical wind shear cooler water caused alma weaken tropical storm storm continued weaken depression day system dissipated tropical cyclone west mainland mexico alma earliest named storm hurricane satellite era east pacific proper hurricane tropical wave came northwest coast africa wave significantly develop moved west atlantic_ocean caribbean_sea crossed central_america increased considerably system organized upgraded tropical depression june depression system moved west northwestward upper level easterly vertical wind shear limited initial strengthening increase convective banding led upgrade tropical storm june southwest strengthening occurred anticyclone aloft fostered additional development june hurricane hurricane began north northwest response trough west_coast united_states strengthening continued storm reached peak strength winds mph minimum central pressure inhg hurricane cloud pattern elongated southwest northeast axis june increased vertical wind shear downgraded tropical storm later day june deep convection tropical storm decreased moved cooler waters downgraded tropical depression june factors depression dissipated tropical cyclone june system quickly lost tropical characteristics small circulation remained cloud field offshore northwest coast baja california days winds eyewall ripped sails outer rainbands storm produced moderate rain mexican states mexico rainfall peaked near remnants brought sporadic rainfall western united_states precipitation reported arizona california colorado nevada wyoming remnants responsible causing june san_diego records began rain fell location rainfall remnant system united_states peaked santa mountains direct damages casualties reported tropical storm tropical wave emerged atlantic_ocean coast africa wave moved central_america northeastern pacific_ocean convection organized system june system organized upgraded tropical depression june south southern tip baja california depression continued strengthen upgraded tropical storm june initially established upper level outflow failed reach hurricane status peaking maximum sustained winds mph movement associated upper level anticyclone north mexico caused exposed easterly vertical wind shear moved generally northwestward eventually placed storm cooler waters caused deep convection system dissipate june diminished tropical depression moved west northwestward low level flow depression dissipated tropical cyclone june lack deep convection hours tropical storm douglas tropical wave moved northwest coast africa june continued westward tropical north_atlantic caribbean_sea significant development wave entered northeastern pacific_ocean june generated area increased organization thunderstorm activity increased late june early june tropical depression formed june south acapulco mexico evidence low level circulation past hours depression moved west northwest direction subtropical ridge north depression satellite analysis indicated depression reached tropical storm force strength upgraded tropical storm douglas june southwest acapulco douglas reached peak strength mph june tropical storm warning issued june discontinued june tropical storm douglas brushed western coast mexico center circulation approached coast mexico june douglas began weaken interaction mountainous terrain mexico system continued weaken despite warm water temperatures favorable upper level conditions douglas dissipated early june south southeast southern tip baja california highest rainfall report mexico douglas totaled deaths damage reported hurricane tropical wave came coast africa june system moved atlantic entered northeastern pacific_ocean wave significant tropical system cyclonic turning lower middle layers system june center circulation located south acapulco mexico system exhibited sufficient organization considered tropical depression june depression quickly strengthened tropical storm later day track west northwestward northwestward june june rainbands moved mountainous region southwestern mexico flooding damage casualties reported result continued strengthening upgraded hurricane early june passing directly later day right reached peak strength mph dropping rain island windows broke result minor structural damage reported result island high pressure area north forced westward june convection began decrease hurricane moved cooler waters weakened tropical storm later day weakened tropical depression july dissipated july tropical depression area disturbed weather south acapulco organized tropical depression june system began northwest originally system expected reach tropical storm strength near hurricane intensity late july early july persistent vertical wind shear system development convection began merge national_hurricane_center discontinued advisories tropical depression stating depression dissipated regeneration unlikely wind shear began decrease convection associated remnants tropical depression quickly began increase low level circulation near edge deep convection national_hurricane_center resumed advisories tropical depression july intensification tropical storm predicted tropical depression remained poorly defined eventually dissipated july hurricane tropical wave came northwest coast africa june wave crossed atlantic_ocean caribbean_sea warm waters northeastern pacific_ocean july area disturbed weather moved northwards tropical depression seven early july depression moved northwest increased organization deep convection designated tropical storm july south mexico weakly defined eye formed july storm upgraded south peaked strength winds mph central pressure inhg july passed north causing northwest wind mph rain location hurricane fluctuated intensity july weakening tropical storm later day west cabo san lucas weakening moved continuing cooler waters downgraded tropical depression june west cabo san lucas depression dissipated tropical cyclone june low level circulation clouds persisted days hurricane tropical wave moved coast africa june moved atlantic_ocean central caribbean_sea little development western caribbean_sea convection developed wave july system better organized moved northeastern pacific_ocean system upgraded tropical depression july depression moved west northwest good outflow north gradually strengthened tropical storm later day continued strengthen reaching hurricane strength july storm approached sustained wind mph gust mph reported weather equipment island failed hurricane began turn west strengthening growing ridge north increasing outflow aloft began form hurricane reached peak strength mph defined eye center circulation turned northwest july area strong vertical wind shear low water temperatures hurricane quickly weakened tropical storm july tropical depression july dissipated tropical cyclone later day reduced circulation cloud field hurricane tropical wave moved northwest coast africa july passed atlantic_ocean caribbean_sea significant development wave moved central_america northeastern pacific_ocean july thunderstorm activity increased system july rainbands present tropical disturbance july tropical depression formed later day southwest acapulco mexico tropical depression strengthened tropical storm july south tropical storm continued strengthen moved northwest hurricane late july continued strengthen passed southwest july reached peak strength mph minimum pressure inhg center circulation south southwest july concentric eyewall located inside formed center time pattern observed eastern pacific hurricane kept category hurricane intensity days hurricane strength days overall hurricane weakened tropical storm july moved cooler waters turned west low level center separated thunderstorm activity steering surface high pressure system north moved cooler waters dissipating tropical cyclone early july hurricane tropical wave moved coast africa july wave moved west moved caribbean_sea wave convection organized system entered northeastern pacific_ocean concentrated convection surface center circulation southeast acapulco moving west northwest tropical depression formed july south mexico early following day depression strengthened tropical storm storm continued strengthening proximity hurricane hurricane july hurricane continued west northwest duration reached peak strength mph july crossed recorded mph sustained wind heavy rain july hurricane weakened following days moved cooler waters downgraded tropical storm july subsequently tropical depression july depression dissipated later day losing low level circulation southwest san_diego tropical depression july tropical disturbance hurricane strengthened tropical depression close proximity west development depression hindered vertical wind shear outflow wind shear dissipated depression july remnants absorbed nearby cyclone damages casualties caused depression sea tropical storm aka tropical storm aka tropical storm form area disturbed weather began organize august august system organized designated tropical depression depression intensified tropical storm moving west south august tropical storm aka peaked maximum sustained winds mph storm continued west approached island weather deteriorate tropical storm crossed international date line august aka weakened depression dissipated days later august tropical depression diana hurricane diana struck eastern mexico managed hold remaining tropical depression entered eastern pacific_ocean late august tropical depression diana entered eastern pacific national_hurricane_center classify system intensification occurred system entered eastern pacific dissipated tropical cyclone following day remnant tropical disturbance developing significant convection moved northwest mexico brought rainfall amounts local areas state remnant disturbance moved august tropical depression tropical depression second tropical cyclone develop north central pacific_ocean depression developed tropical disturbance southeast hawaii better organized night august tropical depression moved west northwest direction hours changed west southwest track august turned southwest depression weakened dissipated august south southeast hawaii tropical depression persistent area thunderstorm activity southwest better organized strengthened tropical depression august moving northwest system developed slowly embedded easterly shear kept system reaching tropical storm strength caused ultimate dissipation august damages fatalities caused depression hurricane tropical wave moved western coast africa august moving atlantic_ocean caribbean_sea significant development system entered northeastern pacific_ocean organized upgraded tropical depression thirteen august centered south acapulco mexico depression moved west northwestward track strengthened tropical storm august strengthening continued reached hurricane strength august cyclone peaked maximum sustained winds mph august storm turned westward began weakening regained tropical storm status august tropical depression status august dissipating tropical cyclone later day damage reported hurricane tropical wave moved coast africa august spawned tropical storm days later moved southern windward_islands august dissipated shortly tropical wave progressed northeastern pacific_ocean wave spawned tropical depression fourteen east southeast hurricane depression moved westward days weakened depression began increase strength tropical storm august continued strengthen hurricane august peaking winds mph day august strong frontal trough weakened high pressure system storm north causing turn north days hurricane weakened response cooler water increasing vertical wind shear removed convection center weakened tropical storm strength august tropical depression august system dissipated tropical cyclone august hurricane tropical wave moved northwestern coast africa atlantic_ocean august moving atlantic caribbean_sea development system moved northeastern pacific_ocean moved northward august thunderstorm activity organized sufficiently system upgraded tropical depression august southeast acapulco mexico depression moved west northwestward strengthened tropical storm south southwest august storm began turn westward strengthening high pressure system north upgraded hurricane august southwest cabo high north continued strengthen hurricane turned west southwest thunderstorm activity hurricane began weaken downgraded tropical storm status august tropical storm turned north northwestward storm passing cooler waters august storm downgraded tropical depression minimal amounts deep convection remaining circulation dissipated tropical cyclone september low level circulation clouds seen satellite imagery days damage casualties reported result hurricane marie tropical wave moved northwestern coast africa august wave moved west atlantic_ocean caribbean_sea significant development wave moved central_america northeastern pacific_ocean august isolated convection system increased south system moved northwest parallel southwest coast mexico convective activity increased system upgraded tropical depression sixteen september centered southwest weaker normal high pressure system controlled movement depression system moved slowly west duration depression strengthened tropical storm marie september hurricane september south southwest marie reached peak intensity mph september hurricane crossed central september hurricane maximum sustained winds mph hurricane weakened september marie regained tropical storm status system weakened tropical depression september dissipated tropical cyclone september near hawaiian coast casualties damages caused marie hurricane tropical wave moved coast africa atlantic_ocean caribbean_sea significant development wave entered northeastern pacific_ocean began signs organized thunderstorm development tropical depression seventeen formed september centered south southwest cabo mexico depression better organized strengthened tropical storm later day september absorbed tropical depression eighteen close proximity strengthened moved north northwestward tropical storm upgraded hurricane september formed eye september storm reached peak strength mph sustained winds day turning north west weakened moved cooler waters downgraded tropical storm later september tropical depression september dissipated tropical cyclone september losing deep convection tropical depression eighteen september satellite images indicated eighteenth tropical depression season formed southwest cabo san lucas located close proximity tropical storm depression soon enter region colder sea surface temperatures national_hurricane_center noted little intensification possible predicted hindered intensification tropical depression eighteen national_hurricane_center noted hours later depression likely absorbed national_hurricane_center later believed tropical depression eighteen dominating interaction systems forecast absorb unlike prediction absorbed tropical depression eighteen later day hurricane tropical wave coast africa september crossed atlantic waters caribbean_sea eventually pacific_ocean weak system area convection entered northeastern pacific_ocean miles south acapulco mexico september tropical depression nineteen formed convection south southeast southern tip baja california depression moved west northwestward track rounding southwest strong high pressure system depression continued strengthen upgraded tropical storm september hurricane september intensity peaked maximum sustained winds mph september hurricane began turn northwestward response high pressure system weakening north began weaken moved cooler waters september cyclone regained tropical storm status september slowly progressed northward system weakened tropical depression status september lost deep convection steered southwestward low level flow dissipated tropical cyclone october remaining low level circulation clouds continued southwestward course tropical storm rachel mid september weak tropical wave moved coast moved westward entered eastern pacific_ocean early september concentrated system south september organized thunderstorm area upgraded tropical depression south acapulco depression developed slowly tropical storm september rachel briefly moved northward curving accelerating mexican coast storm passed southern portion baja california sur october rachel final landfall midway los system landfall eastern north pacific_ocean rachel decayed rapidly land final public advisory rachel issued early october remnants continued accelerating texas lost identity highest rainfall total system mexico totaled near tip baja california northern mexico thousands homeless people died texas rachel remnants caused heavy rain flooding occurred big bend area hurricane polo polo originated tropical wave moved african coast september spawned hurricane atlantic basin september system increased convection moving west approaching central_america southern extent wave crossed pacific_ocean september wave continued westward related thunderstorm activity increased following week convective system organized tropical depression september nearly midway mexico hawaii initially depression drifted northwest large upper level trough located west polo strengthened rapidly hurricane early september winds peaking mph storm small vertical wind shear caused significant weakening october polo regained tropical storm strength crossing north basin dissipated tropical cyclone later day casualties damages caused polo tropical storm simon weakly defined tropical wave moved northwest coast africa september crossed northern portion tropical atlantic northern south_america significant organization wave moved northeastern pacific waters coast colombia september wave passed southern central_america rainbands increased system october october system merged october october signs convective organization reappeared october october system upgraded tropical depression south cabo mexico depression continued develop upgraded tropical storm simon october south southwest high pressure system north northwest simon continued west northwestward path tropical storm continued strengthen peak intensity mph late october simon passed cooler waters weakened tropical depression october depression moved westward course low level circulation displaced deep convection following day simon dissipated tropical cyclone early october open waters northeast pacific hurricane tropical wave moved northeast pacific_ocean formed tropical depression south mexico october strengthened moderate pace reached hurricane intensity october entered favorable environment intensified reaching peak strength october time upper level trough drifted north increased vertical shear causing substantially weaken system category hurricane status trough storm replaced ridge turned storm west led intensification category hurricane upper level trough approached pulled northward hurricane apart cyclone dissipated november eventually moisture spread parts mexico united_states impact land island reported hurricane force winds seven hours unusually large eye large wide fourth strongest pacific hurricane october season season season spent hours life category hurricane longer hurricane basin hurricane area disturbed weather possibly related tropical wave organized tropical depression october strengthened tropical storm early october hurricane days later moved parallel west coast mexico approached southern tip baja california peninsula strike land high pressure area blocked path forced storm small clockwise loop day period loop encountered wind shear cool waters stirred earlier duration weakened tropical storm october depression october cyclone dissipated late october accumulated cyclone energy ace rating table right shows ace storm season ace broadly speaking measure power hurricane multiplied length time existed storms long time particularly strong hurricanes high aces ace calculated advisories tropical systems exceeding knots mph tropical storm strength figures storms basin west basin cumulative ace season fell official normal grading active occurred season intense storms lasted long period time important note highest ace seasons respectively storm names following names named storms formed eastern pacific names retired season list season storms named time names assigned marked gray list aka usage
1990 Pacific hurricane season