 A tropical wave exited the west coast of Africa on August 12 . Although large amounts of deep convection accompanied the system , it was displaced from the poorly defined center . Over the next few days , convection consolidated and by 1200 UTC on August 17 , the system began as Tropical Depression Six , while centered about 690 miles ( 1 @,@ 110 km ) east of the Lesser Antilles . Outflow was initially limited due to light wind shear , though the depression was forecast to become a strong tropical storm by August 20 . It was " highly surprising " to the National Hurricane Center that the depression did not immediately begin to intensity , despite warm sea surface temperatures and light wind shear . Because of a burst in deep convection , as well as satellite imagery estimating winds of 40 mph ( 65 km / h ) , the depression strengthened into Tropical Storm Chris at 1200 UTC on August 18 . 
