The Aleutian low remained in the Bering Straight. The pressure gradient and winds were stronger. Beaufort Sea trajectories showed the air came across Alaska from the Pacific ocean at all levels.
SHEBA ship trajectories show a slightly different picture with the surface and 1.0 km trajectories coming from the Beaufort Sea to the east, and Canada 2 days earlier. From 1.5 km and above, the air came over Alaska from the Pacific ocean to the south.
The satellite visible image shows that the CV-580 crossed extensive open water. Clouds don't appear on the GAC images in the area of the flight. The flight log also noted clear conditions except for a few ice crystals detected in a profile.
