 Almost immediately after emerging into the Gulf of Mexico on July 30 , the cloud pattern of system quickly became better organized . Later after emerging into the Gulf of Mexico , ships and satellite images confirmed that Tropical Depression Four had formed offshore of the north coast of the Yucatán Peninsula ; although it was likely that the depression formed 80 miles ( 129 km ) north of the Yucatán Peninsula several hours earlier than confirmed . The following morning after development occurred , the depression had intensified into a tropical storm 575 miles ( 920 km ) southeast of Texas ; the National Hurricane Center assigned it to the name Chantal . Although it became a tropical storm early that morning , the system was not upgraded to a tropical storm until a reconnaissance flight confirmed tropical storm force winds about six hours later , when sustained winds were already 50 mph ( 85 km / h ) . Tropical Storm Chantal rapidly strengthened thereafter , with weather satellites indicating t – numbers increasing from 2 @.@ 5 to 3 @.@ 5 within twelve hours using the Dvorak technique . Chantal continued to intensify , and headed northwestward at 11 mph ( 18 km / h ) due to weak ridging over Florida . 
