SHEBA ship was on the southwest side of a large high pressure system. The center of the high was northeast of the ship. Stratus clouds were present from 2.5 to 6.5 km. The stratus were thickening during the flight. Light rain and snow were reported in the ship's 00 UT weather observation. The lidar showed a variable cloud base around 2.5 km. The sounding humidity profile showed saturation at 2.5 km and near saturation up to 6.5 km. Satellite images showed some cellular structure on the cloud top at 23:36 UT but not at 00:17 UT. The altostratus clouds were moving to the northeast.
The trajectories to SHEBA ship show the low level air from the surface to 1.0 km came from the Beaufort Sea to the southeast. At 1.5 km the air also came from the Beaufort Sea. But this air parallelled the Alaskan coast before turning north toward the ship. Higher air came from central Alaska to the southeast.
