S Ridge to NW ridge descent

Sunny day with cool N winds. Vestiges of snow from night before last. Climb was in good condition. Of note: 1st 30 m rap on NW ridge can be done in 2-15 m rappels, but 2nd bolted station is 7 or 8 m N on the ledge. ( Not obvious at first glance}
N face of Sir Donald was holding snow and winds appeared strong on the upper third of the mountain.