 Operationally ( in real @-@ time ) , Erin was briefly downgraded to a tropical depression on August 16 , though post @-@ storm analysis indicated it retained tropical storm intensity that day . Early on August 17 , the ship British Cygnet measured 44 mph ( 71 km / h ) winds in relation to the cyclone ; around this time , it was estimated that Erin attained its peak intensity with sustained winds of 45 mph ( 75 km / h ) and a barometric pressure of 1 @,@ 006 mbar ( hPa ; 29 @.@ 71 inHg ) . A temporary northwesterly turn occurred around this time as the storm moved through a weakness in the ridge . Later on August 17 , increasing wind shear took its toll on Erin and convection became displaced from the center . The following day , Erin degenerated into a remnant low about halfway between the Lesser Antilles and the west coast of Africa . The remnants proceeded westward on the low @-@ level trade winds before opening up into a trough early on August 20 , and ultimately dissipated several days later . 
