By September 1 a cyclonic circulation with a diameter of 690 mile ( 1115 km ) was evident on satellite imagery , well to the southeast of the Cape Verde Islands , and several hurricane forecast models anticipated development and strengthening .
By September 1 a cyclonic circulation with a diameter of 690 mile ( 1115 km ) was seen on satellite imagery , well to the southeast of the Cape Verde Islands , and several hurricane forecast models expected development and strengthening .