The tropical wave that would become future Hurricane Trudy became identifiable on satellite imagery as early as September 30, emerging near the African coast off Cape Verde. However, the wave did not show any signs of development until October 16, when the wave developed into a tropical depression several hundred kilometers south of Acapulco. The tropical depression intensified significantly. The ship "Maple Ace" reported tropical storm-force winds about from the center at 1800 UTC on October 18. In less than 36 hours, at 1200 UTC on October 20, Trudy became a powerful hurricane with Category Four equivalent maximum winds of and a minimum pressure of according to satellite estimates. The hurricane was at least as intense as Hurricane Max three years earlier and Hurricane Hernan earlier in the year. Estimates state that Trudy may have been the strongest eastern Pacific hurricane since wind estimates have been available from satellite images.