 A tropical wave moved off the coast of Africa and across the Atlantic Ocean and Caribbean Sea without significant development . The wave entered the northeastern Pacific Ocean and began to show signs of organized thunderstorm development . Tropical Depression Seventeen @-@ E formed on September 10 while centered <unk> mi ( 1 @,@ 220 km ) south @-@ southwest of Cabo San Lucas , Mexico . The depression became better organized and strengthened into Tropical Storm Norbert later in the day . 
