 On October 1 , a disorganized area of thunderstorms existed south of Panama . It gradually headed west @-@ northwestward , slowly organized , and developed deep and concentrated convection . The disturbed area had become organized enough to be considered a tropical depression . Numbered Twenty @-@ Four @-@ E , the cyclone was located about 460 mi ( 740 km ) south @-@ southeast of Acapulco . It moved towards the west @-@ northwest at a speed of about 12 mph ( 19 km / h ) , and by the time it was located about 550 km ( 340 mi ) south of Zihuatanejo , it had intensified into Tropical Storm Winifred . 
