 On September 12 , Norbert absorbed Tropical Depression Eighteen @-@ E which was in close proximity . Norbert strengthened as it moved north @-@ northwestward . The tropical storm was upgraded to a hurricane on September 14 , and formed an eye on September 15 . The storm reached its peak strength of 80 mph ( 130 km / h ) sustained winds that day . Turning north of due west , Norbert then weakened as it moved over cooler waters . It was downgraded to a tropical storm later on September 15 , and then to a tropical depression on September 18 . Norbert dissipated as a tropical cyclone on September 19 after losing all its deep convection . 
