A winter weather advisory is in effect for St. Lawrence County through 1 a.m. Monday with more heavy snow predicted for the area, according to the National Weather Service (NWS).

Forecasters predict 3-6 inches of snow throughout the day that will cause slippery road conditions and poor visibility for motorists.

Snow this morning may mix with rain at times across southern St. Lawrence and southern Franklin Counties, before ending as snow showers this evening, NWS says. The heaviest snowfall accumulations will be near the international border.

Expect temps to drop today into the teens with an overnight low around 17, NWS says.

Frigid temps will move into the region next week, the service says.

The extended forecast for St. Lawrence County is as follows:

Monday

A 30 percent chance of snow showers, mainly after 4pm. Cloudy, with a high near 22. Calm wind becoming northwest around 5 mph in the afternoon. New snow accumulation of less than a half inch possible.

Monday Night

A 30 percent chance of snow showers before 4am. Cloudy, with a low around 10. Southwest wind 5 to 9 mph becoming light west after midnight. New snow accumulation of less than a half inch possible.

Tuesday

Mostly sunny, with a high near 15. Calm wind becoming west 5 to 7 mph in the afternoon.

Tuesday Night

Mostly cloudy, with a low around 3. South wind 3 to 5 mph.

Wednesday

Partly sunny, with a high near 21. Southwest wind 5 to 10 mph.

Wednesday Night

Cloudy, with a low around 14. Southwest wind 6 to 8 mph.

Thursday

Cloudy, with a high near 24. West wind 9 to 13 mph.

Thursday Night

A 50 percent chance of snow showers before 1am. Mostly cloudy, with a low around -1. West wind around 7 mph.

Friday

Mostly cloudy and cold, with a high near 8. Northwest wind 8 to 11 mph.

Friday Night

Partly cloudy, with a low around -16. Northwest wind 5 to 10 mph becoming light and variable after midnight.

Saturday

Sunny and cold, with a high near 7. Calm wind.