tropical storm tropical storm weak tropical cyclone affected parts western united_states august 12th tropical cyclone 9th named storm pacific hurricane season formed west mexico weather disturbance embedded broad system classified tropical depression august quickly intensified tropical storm environmental conditions caused begin weakening cyclone moved northward august transitioned extratropical cyclone approached california remnants produced unprecedented august rainfall numerous traffic accidents power outages meteorological history tropical storm originated broad region active weather persisted west mexico middle august multiple disturbances precursor developed august southwest baja california peninsula later day banding features formed convection began turning nascent area low pressure middle levels atmosphere continued better organized utc august national_hurricane_center classified tropical depression time storm situated approximately southwest cabo outside area tropical cyclones usually form ocean basin depression moved northwestward mph steering currents mid- upper level trough low pressure coast california burst deep convection formed near cyclone center early august estimated maximum sustained winds subsequently increased mph upgraded tropical storm utc time storm reached lowest recorded barometric pressure increasingly colder waters presence southwesterly wind shear immediately stopped intensifying maintained tropical storm status short time early august weakened depression weakening stage deep convection existed northwestern quadrant circulation august cold cloud tops reappeared brief revival attributed non tropical instability utc depression declared extratropical continued northward dissipating near california day later moisture system persisted passed state pacific_northwest ultimately merging larger extratropical cyclone involving remnants hurricane impact tropical cyclone little effect land remnants produced unprecedented precipitation parts coastal california rainfall reached record levels areas amounting san_francisco received precipitation leading august record city recorded rainfall date august contrast area usually receives trace moisture august rainfall represented year event major_league_baseball game august canceled weather rainfall triggered isolated flash flooding locations debris flow deep wine adversely impacted heavy rainfall ruined year unfavorable growing conditions compounded rains hurricane september creating described tumultuous year crops storm contributed numerous weather related traffic accidents classified major collisions occurred night august crashes interstate forced closure lanes minutes blocked large tree fell saturated soil unclear injuries resulted incidents thunderstorms associated storm system left electric customers power lightning struck power outages lasted hours lightning knocked workers unconscious near good condition rainfall extended far north northwestern united_states ending unusually long day dry spell oregon remains significant rainfall tropical cyclone states washington oregon
Tropical Storm Ignacio (1997)