The National Weather Service has posted a hazardous weather outlook for St. Lawrence County for rapidly falling temperatures -- from around 30 this afternoon to well below zero -- and some snow, with winds strong enough to push wind chills to as low as 25 below tonight.

Occasional light snow through this evening will produce total snow accumulations of 1 to 3 inches, nearer to 4 inches in the mountains.

The combination of temperatures near freezing this afternoon with light snow falling will create wet pavement, but as a strong Arctic cold front sweeps across the North Country between 4 and 8 p.m. this evening, temperatures will fall rapidly through the 20s, resulting in a flash freeze with potential areas of black ice, creating a hazardous evening commute.

With temps tonight falling to about minus 10, brisk north winds will produce wind chill values between 15 and 25 degrees below zero at times after midnight tonight.

Tuesday, the high temperatures will only reach the single digits above zero, and it will dip to 20 below or colder Tuesday night.

The NWS forecast for the St. Lawrence Valley and northwestern Adirondacks:

• This afternoon - Light snow. High near 30. West wind around 8 mph. Chance of precipitation is 100%. Total daytime snow accumulation of 1 to 3 inches possible.

• Tonight - Snow showers, mainly before 11pm. Low around -11. Wind chill values as low as -19. North wind 8 to 13 mph. Chance of precipitation is 80%. New snow accumulation of less than a half inch possible.

• Tuesday - Sunny and cold, with a high near 3. Wind chill values as low as -22. North wind around 6 mph becoming calm in the morning.

• Tuesday night - Mostly clear, with a low around -21. Calm wind.

• Wednesday - Sunny, with a high near 19. South wind 3 to 5 mph.

• Wednesday night - Partly cloudy, with a low around 1. South wind around 6 mph.

• Thursday - Partly sunny, with a high near 24. South wind 5 to 8 mph.

• Thursday night - Mostly cloudy, with a low around 11. Southwest wind around 9 mph.

• Friday - Partly sunny, with a high near 22. Northwest wind 7 to 9 mph.

• Friday night - Mostly cloudy, with a low around 4. West wind around 5 mph becoming calm in the evening.

• Saturday - Partly sunny, with a high near 29. South wind around 7 mph.

• Saturday night - Mostly cloudy, with a low around 21. South wind 7 to 13 mph.

• Sunday - Mostly cloudy, with a high near 33. Southwest wind 7 to 11 mph.