Shelter Island Highway Department in final stages of plowing

At about 10:30 p.m. the worst of the all-day snow storm seemed to have passed over the Island.

Highway Department Superintendent Jay Card Jr. was shifting strategies to clearing roads and beginning to intensify the deployment of sand and salt to the surfaces.

Mr. Card said the snow was of a hard-packed consistency on top of ice. It is “extremely slippery and dangerous,” he said, strongly advising residents not to drive and to even stay off the roads on foot because of the dangerous conditions.

Coastal flooding remains a concern, with a coastal flood advisory from the National Weather Service in effect through 1 a.m. Sunday.

Highway Department crews will be out tomorrow doing final cleanups from the storm, Mr. Card said.