With snow and sleet continuing to fall in Riverhead, Town Supervisor Sean Walter and Riverhead police issued a travel advisory to residents.
Roads, police said, are slush-covered and slick, and driving is not recommended.
With sleet falling, the rain snow mix is expected to continue all afternoon before turning to snow Friday evening, police said, adding that a Blizzard Warning is in effect for Suffolk County through Saturday at 1 p.m.
Wind conditions are expected to pick up Friday afternoon, ranging from 30 to 40 miles per hour, with gusts of up to 60 miles per hour, causing major drifting in Riverhead on north-south roads or any roads near open spaces, police said.
Total snow accumulation in Riverhead is expected to total approximately 18 inches, police added.
Residents who must leave their residences or businesses and drive are urged to proceed with extreme caution and reduce driving speed. Authorities urge residents to stay home -- and stay safe.
The storm, police said, is expected to bring moderate coastal flooding, with a high tide Friday night three to five feet above normal. Residents should expect roads in low-lying areas to be flooded over, especially Creek Road in Wading River and Beach Way in Baiting Hollow.
Those who live in the north shore and experienced significant beach erosion during Hurricane Sandy are asked to pay close attention as additional erosion is expected.
Residents are urged to remove their vehicles from the street to facilitate and increase the effectiveness of snowplowing efforts. Fire hydrants near homes should be shoveled out so they remain accessible to emergency responders.
In addition, residents are asked not to shovel out into the street, creating hazards for neighbors.
Any cars parked on a public highway during a snow emergency are subject to fines and towing, police said.
Town officials also urge residents to check on neighbors, especially the elderly and homebound, and to ensure pets are safely in the house.