The National Hurricane Center in Miami said in its 11 p.m. EDT advisory that the former Category 1 hurricane had atrophied to the point where its maximum sustained winds were near 70 mph, down from 80 mph earlier in the day.
Nadine was about 775 miles west-southwest of the Azores as it headed to the east-northeast at 18 mph.
The hurricane center said that while there were no coastal watches or warnings in effect, people with interests in the Azores should monitor Nadine's progress.
The forecasters said the storm, which was generating tropical storm-force winds up to 185 miles from its center, was expected to slow down Monday and turn to the northeast with little change in strength during the next two days.
Notable deaths of 2014 [PHOTOS]