 The northeast movement followed a passing short @-@ wave trough on August 18 ; the forward motion of the storm also increased due to the trough . On August 20 , the steering currents around Arlene collapsed , leading to the storm nearly stalling for 24 hours . During this period , the storm developed excellent outflow and intensified . Operationally , Arlene was upgraded to a hurricane at 2200 UTC on August 20 based on the appearance of an eye @-@ feature on satellite imagery ; however , post @-@ storm analysis indicated that the storm did not attain hurricane @-@ status until 0600 UTC on August 22 . This occurred 14 @.@ 5 days after its formation . 
