A lake effect snow warning is in effect through 1 a.m. Monday for southeastern St. Lawrence County, according to the National Weather Service (NWS).

Heavy lake effect snow is expected with total snow accumulations up to 4 inches north of Hammond to the Colton line and between 4 and 30 inches south of this line, forecasters say.

This is a long duration event that will persist through the weekend impacting post holiday travel plans, NWS sats. Travel could be very difficult to impossible.

High temperatures today will be around 24 with overnight lows around 24.

Little snowfall may occur for northern portions of the warned area with amounts increasing southward, the service says. Several feet of snow is expected in Jefferson County.

If you must travel, expect long delays, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. Stay tuned to NOAA Weather Radio or local media broadcasts for further information.

During lake effect snow, the weather can vary from bands of locally heavy snow to dry weather just a few miles away. Visibilities can also vary greatly. Be prepared for rapid changes in weather, visibility, and road conditions.

The forecast through next Thursday is as follows:

Saturday: Snow. The snow could be heavy at times. High near 32. Southwest wind 7 to 9 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 5 inches possible.

Saturday Night: Snow showers. Low around 19. Southwest wind around 8 mph. Chance of precipitation is 80%. New snow accumulation of 3 to 5 inches possible.

Sunday: Snow showers. High near 30. Southwest wind around 8 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible.

Sunday Night: A 30 percent chance of snow showers before 1am. Mostly cloudy, with a low around 14. Southwest wind 3 to 6 mph.

Monday: A 30 percent chance of snow showers after 1pm. Partly sunny, with a high near 30. Southwest wind 3 to 5 mph.

Monday Night: A 30 percent chance of snow showers before 1am. Mostly cloudy, with a low around 13. Calm wind.

Tuesday: A 40 percent chance of snow showers after 1pm. Mostly cloudy, with a high near 29. Calm wind becoming west around 5 mph.

Tuesday Night: A 40 percent chance of snow showers. Mostly cloudy, with a low around 13. Calm wind.

Wednesday: A 50 percent chance of snow showers. Partly sunny, with a high near 28. South wind 3 to 8 mph.

Wednesday Night: A 50 percent chance of snow showers. Mostly cloudy, with a low around 15. South wind around 10 mph.

Thursday: Snow showers likely. Mostly cloudy, with a high near 31. Southwest wind around 9 mph. Chance of precipitation is 70%.