 On September 12 , an area of thunderstorm activity in the Gulf of Mexico organized into Tropical Depression Nine , about 60 mi ( 97 km ) southeast of Matagorda , Texas . Within three hours of forming , it was named Tropical Storm Humberto , and it turned to the north @-@ northeast before rapidly intensifying . In the early morning hours of September 13 , a Hurricane Hunter aircraft found that Humberto had strengthened into a hurricane while located about 15 miles ( 20 km ) off the coast of Texas . Humberto quickly weakened and entered Southwest Louisiana as a tropical storm during the afternoon of September 13 , dissipating the next day . 
