 The origins of Hurricane Danielle trace back to a tropical wave that emerged off the western coast of Africa and into the eastern Atlantic Ocean early on August 21 . Tracking west @-@ northwestward , the National Hurricane Center ( NHC ) began Dvorak satellite intensity estimates later that morning following the consolidation of convection – shower and thunderstorm activity – near the system 's center . Favorable atmospheric conditions led to further organization , and it is estimated that the disturbance intensified into a tropical depression by 0600 UTC on August 24 , while located roughly 690 miles ( 1 @,@ 110 km ) west @-@ southwest of the Cape Verde Islands . Operationally , the National Hurricane Center initiated advisories at 1530 UTC and noted that the depression was already on the verge of tropical storm intensity . The depression was upgraded to Tropical Storm Danielle later on August 24 following an increase in organization on satellite imagery . 
