Pacific Tropical Storm Irwin was weakening Sunday morning far from the western U.S. and Mexican coasts, forecasters in Miami reported.At 5 a.m., the U.S. National Hurricane Center said Irwin was 865 miles southwest of the southern tip of Baja, Calif., moving northeast at 5 mph.The ninth named Pacific storm of the year had weakened and had sustained winds of 45 mph, the report said.Forecasters said additional weakening was likely in the next two days.Meanwhile, tropical storm-force winds were extending as far as 85 miles from the storm\'s center.There were no weather watches or warnings posted.